Central Park Observing - 30 Nov. 2005

Location: TotL - Central Park's Great Lawn (north end)
Date/time: Wed., 30 November 2005 (5:30p-8:00p)
Optics: 10x70 Fujinon's (mounted)
Conditions: winds var.-WNW 7-9 mph, temp. 54-49°F

Another evening spent nova hunting. The search area is still SALC 34N in Perseus which includes α, ι, κ and δ Persei. Conditions were clear, cool with the wind predominantly from the west. Tonight was the first night working with light blocking equipment. When the wind isn't gusting ‘The Plamp’ and the 12" reflector hold up nicely. They are keepers.

Transparency was consistent throughout the session. The binocular limiting magnitude (BLM) was close to 9.4. Start time was 6:10p. The area was covered in 1 hour and 40 minutes ending around 7:50p. A number of people stopped by to chat and I broke up the nova hunt a few times to show people objects in the binoculars.

James (who knew me from birding) stopped by and talked about an American Kestrel project he was working on so I passed on my email address to him in case he needed any assistance. Part of the project is searching for nests in the city. There are quite a few nests but few locations are known since these falcons (the smallest in North America) are pretty secretive when they want to be.

Mike stopped and asked to look at something, he's been around the site a few times before. I gladly offered to show him the Pleiades. This object in the 10x70's never fails to please. We talked a bit and I recommended a few things for him to look up on the net since he made the request. I thought for a bit and told him to look up ‘ice volcanos’ and ‘Cassini’ since he showed an interest in the planets. I also recommended Neil DeGrasse Tyson's excellent biographer ‘The Sky Is Not The Limit’. Thanks again Peter for introducing me to this book!

Later on Oakley and Harry stopped by. I've never seen them around TotL. Oakley is short and beautiful and has a remarkable pair of eyes. I couldn't actually see what they looked like in the dark but she was able to pick out 7 stars in the Pleiades including Pleione, 5 arc minutes from Atlas. When she saw the cluster in the binoculars she was amazed. She stayed at the eyepiece for quite a long time. A true connoisseur. Can Bogart with the best of them. Coming away from the eyepieces she saw in the stars the figure of a horse and described it fully. I'll need to take a look next time to see if I can see what she saw. Harry walked away with an image of a Unicorn. Power of suggestion?

• Nova Hunting:

Stars Seen:

No stars needed to be added. The chart's limiting magnitude is 9.5 which goes just beyond the limiting magnitude of the Fujinon 10x70's. BLM for the evening was around 9.4.

Number of stars seen: 408 stars in 5°s of declination by 50 minutes of right ascension.

Lunar Occultations: 4-December-2005

Three of the stars involved are very close doubles. Unfortunately only the last of the three will be easy enough to view in a small scope. This star is bright enough and will disappear on the dark edge of the Moon. The other two tight double events occur on the sunlit side.

The Moon's altitude at the start of the series is 19°. It will descend to 13° when the close double 60 Sagittarii (separation = 0.05" (5 hundreths of an arcsecond)), is occulted on the dark limb.

I've never attempted to view tight doubles during a lunar occultation. Given clear skies this should be an interesting evening.

DEFINITION OF TERMS: Vertex Angle - the angle of the event around the limb of the moon measured anticlockwise from the vertex of the lunar limb - i.e. the point on the limb highest from the horizon. To help with above term I've converted it to an "o'clock" time (i.e 01:15 "o'clock") which will shows where the star will be seen on the limb of the Moon as if the Moon were a clock's dial as viewed naked eye or through a pair of binoculars. Cusp Angle - the angle of the event around the limb of the moon, measured from the nearest cusp. Negative (-) values indicate a bright limb event. The cusps are usually N (north) or S (south), but near full moon can be E (East) or W (west). (d/r D/R) If the letter in parentheses next to "Disappearance" and "Reappearance" are lowercase this means the star may not be visible in a small telescope. These events are useful to test the algorithm built into WinOccult 3.1.0 to see how it applies to various telescopes/binoculars.

Event: Total Lunar Occultations
Location: Central Park, New York City
Day/date: Sun., 04 December 2005

[Click on (d/r) or (D/R) for location on limb.]

Star: ZC 2910 (omega Sgr) / Mag.: 4.7
Duration (h:mm:ss): 0:09:34
Sun's altitude at disappearance: -3°

• ome Sgr is a double: mv 5.6 & 5.6, sep. 0.001" (PA 51.3)

¶ Disappearance (d): EVENT #1
Local time: 04 Dec 2005 04:42:17 PM
Vertex angle: 325° / 01:15 "o'clock"
Moon's alt/ill.: 19°SSW/14%
Cusp angle: -9°N

¶ Reappearance (r): EVENT #2
Local time: 04 Dec 2005 04:51:51 PM
Vertex angle: 307° / 01:45 "o'clock"
Moon's alt/ill.: 18°SSW/14%
Cusp angle: -25°N

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Star: SAO 188749 / Mag.: 8.1
Duration: [disappearance only]
Sun's altitude at disappearance: -8°

¶ Disappearance (d): EVENT #3
Local time: 04 Dec 2005 05:09:19 PM
Vertex angle: 347° / 12:30 "o'clock"
Moon's alt/ill.: 17°SSW/14%
Cusp angle: +18°N

EVENT #8: Check for reappearance starting at 5:48 PM around 3 "o'clock" on the dial.

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Star: SAO 188724 / Mag.: 7.7
Duration: [reappearance only]
Sun's altitude at reappearance: -8°

¶ Reappearance (r): EVENT #4
Local time: 04 Dec 2005 05:10:43 PM
Vertex angle: 229° / 04:15 "o'clock"
Moon's alt/ill.: 16°SSW/14%
Cusp angle: -80°S

Note: 188724 is double: mv 8.4 & 8.4, sep. 0.100" (PA45.0)

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Star: SAO 188764 / Mag.: 8.9
Duration: [disappearance only]
Sun's altitude at disappearance: -8°

¶ Disappearance (d): EVENT #5
Local time: 04 Dec 2005 05:11:09 PM
Vertex angle: 31° / 11:00 "o'clock"
Moon's alt/ill.: 16°SSW/14%
Cusp angle: +62°N

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Star: SAO 188779 / Mag.: 8.7
Duration: [disappearance only]
Sun's altitude at disappearance: < -12°

¶ Disappearance (d): EVENT #6
Local time: 04 Dec 2005 05:36:41 PM
Vertex angle: 38° / 10:45 "o'clock"
Moon's alt/ill.: 14°SW/14%
Cusp angle: +73°N

---

Star: ZC 2914 (60 Sgr) / Mag.: 4.8
Duration (h:mm:ss): 1:01:47
Sun's altitude at disappearance: < -12°

ZC 2914 is double: mv 5.8 & 5.8, sep. 0.050" (0.0PA)

¶ Disappearance (D): EVENT #7
Local time: 04 Dec 2005 05:42:40 PM
Vertex angle: 16° / 11:30 "o'clock"
Moon's alt/ill.: 13°SW/14%
Cusp angle: +53°N

¶ Reappearance (r): EVENT #10
Local time: 04 Dec 2005 06:44:27 PM
Vertex angle: 227° / 04:30 "o'clock"
Moon's alt/ill.: 5°SW/14%
Cusp angle: -88°N

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Star: SAO 188817 / Mag.: 8.0
Duration: [disappearance only]
Sun's altitude at disappearance: < -12°

¶ Disappearance (d): EVENT #9
Local time: 04 Dec 2005 06:31:26 PM
Vertex angle: 53° / 10:15 "o'clock"
Moon's alt/ill.: 7°SW/14%
Cusp angle: +84°S

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Recent Purchase: The Plamp

‘Plamp’ is short for ‘Plant Clamp’.

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For the longest time I've been looking for a solution to block stray light at my current observing location in Central Park. The lampposts at TotL are further apart than most of the lampposts surrounding the Great Lawn but they still create enough glare to make observing difficult.

Central Park Lamppost

An articulated arm that could hold a light shield seemed like the right solution but I couldn't easily find one on-line. I finally went down to B&H Photo to take a look around. Nobody in the store could point me to the right product so I decided to hit the lighting section. Nothing on display seemed right. Too heavy!

After roaming around the department for a few minutes I saw two products. Both had articulated arms that could clip-on to a tripod and both had clamps on the end. The smaller of the two seemed to fit the bill. The ‘neck’ is 19" long with 33 articulations. I also purchased a 12" round black/silver light shield.

This should do the trick!

Central Park Observing - 20 Nov. 2005

Location: TotL - Central Park's Great Lawn (north end)
Date/time: Sun., 20 November 2005 (6:05p-8:15p)
Optics: 10x70 Fujinon's (mounted), Tele Vue-76
Conditions: winds var.-SW from 5-9 m.p.h., temp. 53°F

Another evening dedicated to the hunt. The search area is SALC 34N in Perseus which includes α, ι, κ and δ Persei.

Conditions were clear, cool with a south-west wind blowing on my back. Tonight was the first night working with a Cartes du Ciel (CdC) chart printed with asterism lines.

Transparency improved as the session progressed. The binocular limiting magnitude (BLM) was 9.2 early on increasing to 9.3+ towards the middle of the session. Start time was 6:05p. The full area was covered in 1.5 hours ending around 7:35p.

This is quickest I've been able to cover all of SALC 34N. I don't think it can get much quicker if I'm going to thoroughly check out the starless regions for potential novae. Having a chart with a limiting magnitude of 9.5 helps eliminate the time spent triangulating and plotting stars that aren't on the chart.

Ken was setup at the top of the lawn showing Venus to a small crowd through a spotting scope. Tom C. showed up a bit later. Both left early on.

NOVA HUNTING:

Variable Stars:

V410 Persei was seen for the first time tonight. It was the dimmest star in the area surrounding the ‘Three Boxes’ asterism making it ~9.2. V410 Per is a semiregular variable with a late-type spectrum (M, C, S or Me, Ce, Se). The quoted range is between 8.8 and 9.4. The period is listed as 110 days. This star should be visible in the 10x70's, even at its dimmest, on most evenings.

Here is a description of an SRB variable star from the General Catalog of Variable Stars (GCVS):

Semiregular late-type (M, C, S or Me, Ce, Se) giants with poorly defined periodicity (mean cycles in the range of 20 to 2300 days) or with alternating intervals of periodic and slow irregular changes, and even with light constancy intervals (RR CrB, AF Cyg). Every star of this type may usually be assigned a certain mean period (cycle), which is the value given in the Catalogue. In a number of cases, the simultaneous presence of two or more periods of light variation is observed.

The chart's limiting magnitude is 9.5 which goes just beyond the limiting magnitude of the Fujinon 10x70's in Central Park. BLM for the evening was 9.2 - 9.4.

Number of stars seen: 419. Area covered: 5 degrees of declination by 50 minutes of right ascension.

Irons in the Fire

• Double star list for ‘Planetarium for the Palm’
• Updating list of confirmed novae for charting purposes
• Searching for novae

Unflagging effort is probably the most important quality needed in finding a nova. Alfredo Pereira, discoverer of Nova Aquilae 1999 No. 2, introduced me to the word ‘assiduity’ from the article linked to. Assiduity levels are hard to keep up.

Research on topics related to novae are keeping me from going out into the field as often as I'd like. Cloudy nights are not helping.

• A project I'm involved with, not related to novae, is reducing the Paul Couteau table of double stars for the software program ‘Planetarium for the Palm’.

This involves researching the stars on the Internet including updating the orbits based on an Excel program I found on the web. I'll probably split the list of 744 stars into at least 3 groups based on the separation of the primary/secondary stars.

• The nova related project involves creating a list of all known novae bringing the list as up to date as possible.

I became most interested in nova hunting when I produced the following chart based on a preliminary list of 361 novae. The drop-off of ‘finds’ for stars reaching maximum visual magnitude that are greater than 7th mag. was intriguing to say the least. Here is a rough idea of what I saw:

Mag  No. Graph
>1st  3  #
1st   2  #
2nd   5  ##
3rd   5  ##
4th  12  ######
5th  14  #######
6th  24  ############
7th  51  #########################
8th  39  ###################
9th  45  ######################
10th 34  #################
11th 32  ################
12th 14  #######
13th  9  ####
14th  8  ####
15th  5  ##
16th  6  ###
17th  3  #
18th  2  #
99th  3  #

You would think that the number of ‘finds’ would increase as magnitudes increase. I wouldn't have guessed that there was a drop off after 7th magnitude.

This is main thing that prompted me to search for novae visually at a limiting magnitude deeper than 7th magnitude.

AMS List of Fireballs (2005)

The following site was passed onto me by Tom C. showing all fireball sightings reported to the American Meteor Society (AMS) for 2005.

An entry for November 11th 2005 at 10:28pm shows a fireball witnessed at the same time in the same place in the sky from both Philadelphia, PA and New York, NY.

• Fireball Sightings Table: 2005

Scroll down to entries 371a & 371b to see the both entries for this Taurid Fireball on the ‘Fireball Sightings Table’.

See previous post for details on the New York City sighting.

Asterism List for SALC 34N in Perseus

Below is a list of asterism names for SALC 34N. I've finished laying out the figures in the planetarium program Cartes du Ciel (CdC). An example, and a short write-up, for a few of the asterisms appears at the end of this post:

» See examples below table «

ASTERISM NAMES
Bromeliad	Orange Slice
Single Box	Mace
ι Per "Kite"	Cubist Lady
Three Boxes	Three Kings
Triangle Man	River Styx
Sm. Witch's Hat	Keystone
Transformer	Gooseneck Lamp
Water Jar	Nautilus
Greek Capital - Σ	Clog
κ Per "Ship"	Home Plate & Triangle
Five Doubles	Pegasus
Lg Witch's Hat	Sextant
Little Dipper	Bowtie
Segmented Dog

[ IMAGE] SALC 34N Asterism - ‘Bowtie’

[Click on the variable names for details from a previous post]

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This is an image of the ‘Bowtie’ asterism which exists along the southern edge of SALC 34N. One of the variables I'm following, called Y Persei, is just right/south of the ‘knot’.

Also near the asterism is GK Persei AKA Nova Persei 1901 which became the brightest ‘new star’ since the two supernovae from nearly 300 years before Nova Persei 1901 appeared. The supernovae are refered to as Tycho's Star (1572) and Kepler's Star (1604).

The size of the asterism is ~1.5° x 0.75°. The limiting magnitude is 9.5.

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[Image] SALC 34N Asterism - ‘Bromeliad’

The above link shows an asterism in SALC 34N I call ‘Bromeliad’. This is the first one created for this region and remains unchanged from the day it was created.

This flowering plant often collects water used to capture protein in the form of insects and other organic material. The flowers will make use of the nutrients in this debris.

The size of the asterism is ~2° x 1.5°. This one includes the brightest star in Perseus - Mirfak (α Persei) - and a portion of the Perseus OB3 Association. West is up and north is to the left. The limiting magnitude is 9.5.

The water level and the doomed fly are both represented in this figure.

Central Park Observing - 10 Nov. 2005

Location: TotL - Central Park's Great Lawn (north end)
Date/time: Thu., 10 November 2005 (7:40p-9:45p)
Optics: 10x70 Fujinon's (mounted)
Observers: Peter T., Kin L.
Conditions: winds from 8-15 m.p.h., temp. 45°-43°F

Tonight was dedicated to nova hunting in Perseus. The search area is still the north portion of SALC 34. I'm very close to finalizing the asterisms. Tonight was the first night working with a pencil & ruler chart.

I'm ready to create asterisms for the planetarium program Cartes du Ciel (CdC). This is one of the reasons I've taken off from observing under a clear sky. I'm convinced Leslie Peltier would never have done such a thing.

Observing was broken up somewhat by heavy clouds moving through. Luckily they moved out fairly quickly creating down time of approximately 15 minutes. It was fun watching the clouds move from the field revealing rich star fields in the binoculars.

The observing chair I use is made of wood and fairly lightweight. Lightweight is important since I travel on foot or by bus to observe. The chair I use is The Beer Chair.

I started nova hunting with a pair of Fujinon 7x50's but felt I should go deeper as long as I could maintain a decent field of view. The Fujinon 10x70's fit the bill. The gain over the smaller binoculars is almost a full magnitude. The FOV is 5°18' (5.3°) compared to the 7.5° FOV for the 7x50's. Any deeper would show too many stars to track & map successfully.

The session started at 7:40p and ended at 9:45p. The full search area was covered. While I was checking out the ‘new stars’ on my PDA program ‘Planetarium for the Palm’ for any ‘suspect’ stars I spotted one star I wanted to check again. When I went back to observe the skies were completely obscured. The cloud cover was thick enough so only the Moon, Mars and Capella could be seen.

During this time we were able to spot a 22° halo surrounding the Moon. Only half the full circle was detected. It was subtle, not obvious like the same feature surrounding the Sun.

I should be out there now to checking up on that star!

NOVA HUNTING:

SALC Date & Tot. Time  BLM    Optics
34N  2005/11/10 2h05m  9.6 Fujinon 10x70

Hand Plotted - Stars dimmer than mag. 9.1:

15 stars were plotted by hand on the original chart. These stars were dimmer than the limiting magnitude of 9.1 on CdC. Only 2 of these stars were not seen: a mag. 9.03 star (CdC shows this object dimmer than 9.1) off of the ‘Three Boxes’ asterism (TYC 3319- 366-1) and the variable star V410 Persei also within the ‘Three Boxes’.

Additional Stars Not on Chart:

53 additional stars were spotted and plotted. All but one were cleared as ‘non-novae’. The range of the stars not plotted was 9.03 - 9.64. A mag. 9.86 star (TYC 3312-1838-1) was seen in the ‘Transformer’ asterism which does not appear to be a double needing to have its magnitude corrected. This is much deeper than I should be able to see. I'll need to check into this star a bit more.

Number of stars seen: 367 plotted, 13 added and 53 additional. Total of 433 stars. Area size: 5°s of declination by 50 minutes of right ascension. I will need to lower the limiting magnitude of the chart to include most of the stars seen in the past few sessions.

NYC Taurid Fireball - 11 Nov. 2005

Brighter than Venus!

As I was waiting for a late night coffee to brew I went over to a north facing window to look at the stars. I was testing my variable star skills to see which stars are brighter than others.

The skies in N.Y.C. are currently cold & crystal clear.

Seconds after arriving at the open window I saw a brilliant white streak that wasn't your typical meteor. It grew brighter than Venus and appeared to sparkle towards the end of its flight. The whole event lasted less than a second.

It originated from the general direcion of Capella and ended its orbit at a point about halfway up from the northern Pointer in the Big Dipper (α Ursa Majoris - Dubhe) and Polaris. It left a naked eye smoke trail.

Plotting it on SkyMap Pro shows that the path in the sky was at least 25° and the direction it was travelling from leaves no doubt about which comet this originated from - Comet Encke.

My northeast facing window (aka Manhattan north) perfectly framed the end of the line for one of a seemingly endless source of meteors.

I don't think it was a Bolide because the only sound heard was the quickening of my heartbeat.

[Image] Path of Taurid Fireball - 11 Nov. @ ~10:28 PM

Wikipedia: Bolide, Taurids

Central Park Observing - 7 Nov. 2005

Location: Central Park's Great Lawn (north end) [TotL]
Date/time: Mon-Tue, 7-8 Nov. 2005 (~7:00p-12:00a)
Optics: 10x70 Fujinon's (mounted)
Observers: Charlie R., Peter T., Kin L.
Conditions: winds variable 5-7 m.p.h., temp. 58°-53°F

The skies were clear when I left the house. When I arrived at the park some high cirrus started to appear. Soon after arriving Charlie, Peter & Kin showed up under skies blanketed with light cloud cover. Things were to change soon.

The nova hunt started around 7:30pm while looking through clouds. During this first session it was possible to see down to magnitude 8.5 in the 10x70's instead of the typical binocular limiting magnitude (BLM) of 9.2 to 9.3.

We waited around and talked as the clouds kept coming. Then suddenly the sky was crystal clear! I resumed the hunt in SALC 34N around 9:30p in Perseus and was able to see stars down to 9.40 which is the best I've been able to do since purchasing the Fujinon's. Naked eye limiting magnitude (NELM) for me was slightly better than 5.0.

While searching during the 1st session I made some connections between the asterisms. Since I was able to see only the brightest stars this allowed me to get a feel for larger arrangements which spanned a number of asterisms clearly showing the relationships between them. This was a big help and I'll try to incorporate this technique even when the skies are not lightly covered with clouds.

At the start of the session, around 7:30p, the center of SALC 34N was ~40° above the horizon. This is in my comfort zone of a 30° - 50° altitude when viewing with tripod mounted bincoculars on a video head. At the beginning of the 2nd session, around 9:30p, the center of the SALC rose to ~60°. At the end of the hunt the center was at ~70°. Viewing objects above 50°+ altitude with the current setup puts a strain on the neck but is obviously doable. I wouldn't want to this too often.

Observed with the Teleport 10":

• Deep Sky:

Messier 1 (Supernova Remant: 6x4', distance ~6,500 l.y.) Very impressive to see this object from the heart of N.Y.C. Peter star hopped to the Crab Nebula after an off the cuff comment asking if he's seen M1 from the city. I was surprised he picked it up but then again his observing skills are top notch and improving all the time. Messier 1 is barely discernable from the background and is most noticeable when moving the scope slightly.

Seeing a supernova remant for the first time from the light pollution capital of the world was a great treat. Thanks for the views Peter!!

Observed with the Fujinon 10x70's:

• Globular Clusters:

Messier 15 in Pegasus was picked up easily and shared with Peter T. The bright core was evident at 10x. It's good to see how much he appreciates viewing objects with any type of optical aid including unassisted optical observations i.e. ‘naked eye’.

• Double Stars:

ψ Draconis, STF 2241 AB (mag. 4.9 & 6.1 / sep. 30.0") splits easily and cleanly with the 10x70's.

40 & 41 Draconis, STF2308 AB (5.7 & 6.0 / sep. 18.6") The pair was pointed out to us by Charlie which he split with the 15x50's. In the Fujinon 10x70's this is a wonderful double. Both components are nearly equal in magnitude with black space separating the stars.

• Nova Hunting:

Category 2 - Stars needing effort to see:

This category wasn't quantified.

I wanted to get through the area as quickly as possible since it was going to rise out of range of the tripod mounted binoculars. My feeling during the transparency rich portion of the night was that stars down to 9.40 were visible with a bit of effort which is considerably deeper than previous nights out with the Fujinon 10x70's.

The dimmest stars: TYC 2874-1527-1 (mag. 9.39), TYC 2874-2178-1 (mag. 9.36) [both in the ‘Bowtie’]; TYC 3311-2297-1 (9.34), TYC 3311-1669-1 (9.33) [both in the ‘Small Witch's Hat’] are not listed as doubles in the catalogs. These are probably correct visual magnitudes.

Category 1 - Stars easily seen:

This was also not quantified.

Variable Stars:

Only 4 variables are looked for in this region on a regular basis and I only noted whether they were seen or not. Here are details on variable stars in SALC 34N from a previous post:

• Y Per (mv 8.4 - 10.3, var. type Mira, per. 248.6 days) was visible in the ‘Bowtie’ asterism.

• V410 Per (mv 8.8 - 9.4, var. type SRB:, per. 110 days) again this star was not visible in the eastern most of the ‘Three Boxes’ asterism.

• NSV 15682, SAO 38803, BD +48 0908 (mv 8.4 - 9.6, var. type E:) was visible and definitely brighter than nearby HIP 15862 which is mag. 9.0. This is in the ‘Bromeliad’ asterism.

• NSV 15684, BD +47 0819 (mv 8.5 - 10.0) is easily visible each time I'm out observing. I still need to look into this star a bit more to see what is meant by ‘Flared on 9 Jan 1992’. This star is in the tail of the ‘Segmented Dog’ asterism.

The last two stars are New Suspected Variables (NSVs). I don't know it they are ‘known’ variables yet.

The total number of stars plotted in SALC 34N was 277 in 22 separate asterisms. Twelve new stars were plotted that weren't on the original chart.

While Still @ the Office - Wed, 2 Nov '05

Arrived home as Gemini rose
beyond twin water towers
of the Upper East Side.

Central Park Observing - 30 Oct. 2005

Location: TotL - Central Park's Great Lawn (north end)
Date/time: Sat-Sun, 30-31 Oct. 2005 (~6:10p-12:45a)
Optics: 10x70 Fujinon's (mounted)
Observers: Charlie R., Peter T., Kin L.
Conditions: winds mainly variable & from the southwest 3-12 m.p.h., temperature 64°-58°F

First day of ‘standard time’ observing with friends. The skies were clear with a few patches of light cloud which cleared as the temperature dropped.

The first part of the evening was spent nova hunting in Perseus. The current search area (SALC 34N) was completed in 2h00m (6:40p-8:30p). This area is 50 minutes in ‘right ascension’ by 5 degrees of ‘declination’. I took a ten minute break around 7:25p. The whole area was covered with the binocular limiting magnitude (BLM) a few tenths short of ideal due to the light cloud cover for part of the session.

The balance of the night was spent talking and observing.

Peter's 10" dobsonian was mainly aimed at Mars and the views were spectacular when seeing allowed. I don't know much about the topography of Mars but a lot was seen including a few glimpses of Hellas. Hellas was only visible when the dusky markings near the southern limb were clearly seen. These markings were not visible while the disk was skipping about. The appearance of Hellas was as if it were being held in the arms of a spider.

A lighter gap along the dark bar, well east of Syrtis Major, was obvious. This appears to be between Mare Cimmerium and Mare Tyrrehenum.

It was good to have the 10" to view this close approach of Mars. I haven't taken out the Televue-76 in awhile. It would probably have been a bit frustrating, but nonetheless satisfying, to have viewed Mars solely with a 3" glass.

Objects observed with the 10x70's:

• Globular Clusters:

Both M15 in Pegasus and M2 in Aquarius were placed in the 10x70's for all to view.

• Open Clusters:

M34 in Perseus was looked at early on in the 10x70s's.

NGC 2281 in Auriga (mag. 5.4): star hopped from Gemini to an asterism that looked like the five on the side of a dice. To it's lower left was a peaked roof-like asterism with the cluster sitting on the right edge of the roof. Fairly obvious, elongated and small with some stars resolved. With averted vision the cluster was more easily picked out from the background stars and appeared nebulous. This was a pleasure to view in the 10x70's. Peter was able to see it but no one else felt they saw the object.

• Solar System:

At least half a dozen Taurid meteors were seen. The ones spotted naked eye were bright, fast and fairly white. Two were seen in the binoculars.

Uranus was seen by star hopping from the ‘Water Jar’ in Aquarius. Some movement has been noticed over the past month. This is probably due more to our motion than to Uranus'.

Saturn was placed in the 10x70's with the Beehive Cluster at the top edge of the 5.3° field of view.

• Double Stars:

ψ Draconis (mag. 4.9 & 6.1 / sep. 30") easily split with the 10x70's and clearly seen by the majority of the group.

π Andromedae (mag. 4.4 & 8.6 / sep. 35.6) not so easily split since the secondary is near the limit of the 10x70's. The large four magnitude difference doesn't make the task any easier. Both Peter and myself were able to see the dimmer star in the correct position. We confirmed this with a view in the 10" dob.

η Persei (mag. 3.8 & 8.5 / sep. 28.3) tried in the 10x70's but not successful. Splits easily with the 10". The problem with this pair is probably the 4.5 mag. difference between the components.

• Nova Hunting:

Category 2 - Stars needing effort to see:

Seventeen stars were not plotted on the chart and they all fell under this category. The magnitude range was 8.88 - 9.47. Excluding five outliers, two with bright magnitudes of 8.88 & 8.91 plus three with dim magnitudes of 9.36, 9.38 & 9.47, the ‘core’ range for stars needing some effort to view was 9.03 - 9.23.

After taking a closer look at the three dimmest stars I found that two are close doubles with incorrect combined magnitudes:

• BU 1294, TYC 3311-1731-1, SAO 38740, BD +46 0734
RA 03h 20m 40.6s / Dec +46° 40' 47.5"

This star is listed as mag. 9.47. The bright stars in this multiple are 9.66 & 10.28. Separation of the components was 8.1" / P.A. 237° in 1991 & 5.4" / P.A. 54° in 1896. The combined magnitude is 9.17. This falls well within the ‘core’ range listed above. This star is located in the ‘Small Witch's Hat’.

• HLD 8, TYC 3320-1240-1, HD 21539, BD +49 0950
RA 03h 30m 34.7s / Dec +49° 47' 21.2"

This star is listed as mag. 9.38. The bright stars in this multiple are mag. 9.42 & 9.79. Separation of the components was 2.3" / P.A. 177° in 1998 & 1.9" / P.A. 177° in 1881. The combined magnitude is 8.84 making it 0.2 brighter than the ‘core’ range listed above. This star is located in the bottom ‘left’ extention of the ‘Bromeliad’.

• TYC 3326-1645-1
RA 03h 46m 46.1s / Dec +46° 29' 54.1"

This star is listed as mag. 9.36. The catalogs don’t show that this as a multiple star. Maybe the mag. of the star is incorrect or it is slightly variable. It is over a full tenth of a mag. dimmer than the ‘core’ range listed above. This star is located in the ‘tail end’ of the ‘Nautilus’.

Fourteen stars were plotted on the chart and took some effort to notice. The magnitude range of these were 8.51 - 9.01. Excluding the two brightest at magnitudes 8.51 & 8.58 the ‘core’ range for stars needing some effort to view was 8.70 - 9.01.

Category 1 - Stars easily seen:

This category is difficult to quantify without looking at all of the stars at the dim end of this group. Looking at the data above I would say the stars in this range are probably all brighter than approximately 8.7. Analysis of all the stars in this group should reveal some discrepancies as seen in the group above. Over the two hour session the BLM appeared to fall short by a few tenths due to some very sparse and light cloud cover. This cleared up towards the end of the task.

Variable Stars:

Only 4 variables are looked for in this region on a regular basis and I only noted whether they were seen or not:

• Y Per (mv 8.4 - 10.3, var. type Mira, per. 248.6 days) was visible in the ‘Bowtie’ asterism and was in the magnitude range 8.6 - 8.9.

• V410 Per (mv 8.8 - 9.4, var. type SRB:, per. 110 days) was not visible in the eastern most of the ‘Three Boxes’ asterism.

• NSV 15682, SAO 38803, BD +48 0908 (mv 8.4 - 9.6, var. type E:) was visible and possibly brighter than 8.7. This is in the ‘Bromeliad’ asterism.

• NSV 15684, BD +47 0819 (mv 8.5 - 10.0) is easily visible each time I'm out observing. I assumed from the note ‘Flared on 9 Jan 1992’ meant it was at or below mag. 10.0 and shot up once to mag. 8.5 in 1992. I'll need to look into this star a bit more. This star is in the tail of the ‘Segmented Dog’ asterism.

The last two stars are New Suspected Variables (NSVs) and aren't accepted variable stars yet.

The total number of stars plotted in SALC 34N was 342 in 24 separate asterisms.

---

Overall a very successful evening out. It was enjoyable having the full TotL crew in attendance.

Visual Nova Hunting: An Opinion

The included quote at the end of this post is from a recently published article called ‘Observing Variable Stars, Novae and Supernovae’ by Gerald North published in 2004.

The sentiment expressed by Gerald North is probably commonly felt by most amateur astronomers. [See 9.8 Nova Hunting below.]

The reason I started a visual nova hunting program is to learn as much about the night sky as possible. Studying the Milky Way, which is where most novae occur, is not a bad way to get acquainted. It is also a good way to start up a variable star program which I've been interested in for quite awhile.

The one advantage the visual nova hunter has is the ability to see a nova in real time where the automated patrols, if they rely on delayed processing, will have to wait while the visual hunter has a chance of reporting the find before the outburst is noticed by others.

I don't seriously expect to find a nova in my lifetime due to automated patrols but since I'm having a good time trying I will continue the activity. I think my chances of finding a nova are still somewhat better than hitting the lottery! ;-D

9.8 Nova Hunting

This is a book about observing already known objects with a view to following their brightness changes, not a book about hunting down new examples. However, you are certainly not alone if you hanker to discover new objects yourself - but I must offer a warning. Increasingly professional programs of automated sky-searching are mopping up the new objects to be seen in the heavens. In addition a few highly motivated (and usually very expensively equipped) amateurs are vigorously doing the same. Discovering a genuinely new comet, asteroid, variable star, nova, or supernova from your own backyard is now very much harder to do than it used to be despite modern technology. It is now only fractionally short of 100 per cent certain that someone else will have seen and recorded that new object before you.

If you really are determined to become a nova hunter, then to have even the slightest chance of success you must devote yourself to that task almost entirely. You will have precious little time or energy left for other lines of observational astronomy. If you choose that route, then this is not the book to help you. I do cover nova hunting amongst other subjects in my book Advanced Amateur Astronomy, which was published in its second edition by Cambridge University Press in 1997. The one caveat I would warn you about is that in 1996 (when I wrote that edition) it was still reasonable for hunters to use entirely visual means and a pair of good binoculars to do their hunting. While the chances of success will never quite fall to zero using that method, they cannot be very much above that by now.

Question: How many visual nova hunters are active these days?

Variables: SALC 34 North

An important task is to identify all variable stars that can become as bright as the stars at the limit of the binocular limiting magnitude (BLM). For the Fujinon 10x70's this is currently ~9.4+. Searching at the BLM takes some effort so I've chosen an effective BLM (eBLM) of mag. 9.0.

For this purpose I set up an Excel file back in December of 2004 to filter on all known variables. This file contains all the stars in the General Catalog of Variable Stars (GCVS) which numbered 63,265 stars at the time. The filesize is ~37 megabytes.

The outline of the 'search area location chart' (SALC), in Right Ascension (RA) and Declination (Dec), is entered including a buffer zone. The buffer zone should include all stars in asterisms that extend beyond the boundaries of the main search area. This zone varies for each SALC.

SALC 34 (North) in Perseus:
• RA: +03h 50m - +30h 00m (buffer: 00h 07m)
• Dec: +50° - +45° (buffer: +01° 30')

This file identifies all variables in the SALC/buffer zone allowing one to filter on stars in any of the following categories:

• Spans - Stars that span the eBLM and change brightness by at least 3 tenths of a magnitude. These stars will become dimmer and grow brighter than the eBLM. These can easily be confused for a novae without knowing them beforehand. Four stars fall into this category for SALC 34N. See below for details. [Each variable has hyperlinks to two on-line catalogs. The 1st hyperlink after 'Name:' accesses SIMBAD & the last hyperlink accesses the GCVS.]

• Br.>.3 - Stars that change brightness by at least 3 tenths of a magnitude and are listed as always brighter than the eBLM. Four stars fall into this category. Only one, LX Per (8.1 - 8.9) comes close to the eBLM. See details below.

• Dim>.3 - Stars that change brightness by at least three tenths of a magnitude and are listed as always dimmer than the eBLM but no dimmer than three tenths of the eBLM. One star, NSV 15688, falls into this category ranging from 9.1 - 10.3 mag. See below for details.

Historic Novae (SALC 34 complete):

NOVA Persei 1901, GK Persei, [1] [2] - mv 0.2 - 14
RA 3h31m12s / Dec +43°54'15"
From Burnham's Celestial Handbook by R. Burnham Jr.

“Nova Persei 1901. About 4.5° NE of Algol. The first bright nova of the 20th Century, first noticed on February 21, 1901, by the amateur astronomer T.D. Anderson of Edinburgh, Scotland. At that time the star was of the 2nd magnitude, but within 2 days it had increased its light more than 6 times, and attained its maximum brilliancy of magnitude 0.2 on February 23.”

• SEARCH: AAVSO - charts, VSoM, publ. | ADS | Google | wiki.

NOVA Persei 1974, V400 Persei, [1] [2] - mv 8 - 18.26
RA 3h7m38s / Dec +47°7'40"
From “The UK Nova/Supernova Patrol—The First 25 Years” by Guy M. Hurst, 15 April 2000

“However in 1974, a nova was found in Perseus by N. Sanduleak and announced on IAU Circular No. 2716, and later designated V400 Persei. Although the nova had already faded to magnitude 11 by the time it was found on an objective prism plate of November 9, 1974, there was a possibility that it had been brighter at an earlier date and been missed.”

• SEARCH: AAVSO - charts | ADS | Google

Variable Stars (eBLM set to 9.0):

Span's eBLM (Range > mv 0.3):

Name: Y Persei, HD 21280, HIP 16126
RA / Dec: 03h 27m 42.39s / +44° 10' 36.5"
Magnitude, Max. - Min.: 8.1 - 11.3
Type / Period: Mira / 248.6 days
Spectrum: C4,3e(R4e)
• SEARCH: AAVSO - charts | ADS | Google

Name: V410 Persei, HD 19881, HIP 15026
RA / Dec: 03h 13m 38.65s / +47° 49' 33.9"
Magnitude, Max. - Min.: 8.8 - 9.4
Type / Period: SRB: (Semiregular late-type) / 110 days
Spectrum: C7,4(Np)

Name: NSV 15682, TYC 3320-1183-1, BD +48 0908
RA / Dec: 03h 25m 13.8s / +49° 10' 04"
Magnitude, Max. - Min.: 8.4 - 9.6
Type / Period: E: (Eclipsing Binary) / no period listed
Spectrum: K2

Name: NSV 15684, TYC 3316-1812-1, BD +47 0819
RA / Dec: 03h 25m 29.5s / +47° 58' 03"
Magnitude, Max. - Min.: 8.5 - 10.0
Type / Period: Flare on Jan. 9, 1992 / no period listed
Spectrum: A5V

Brighter than eBLM (Range > mv 0.3):

Name: LX Per, TYC 3315-1535-1, HIP 15003
RA / Dec: 03h 13m 22.37s / +48° 06' 31.3"
Magnitude, Max. - Min.: 8.1 - 8.93
Type / Period: EA/AR/RS / 8.038207 days
Spectrum: G5IV+G5IV

Name: V572 Per, HD 20096, HIP 15193
RA / Dec: 03h 15m 48.68s / +50° 57' 21.2"
Magnitude, Max. - Min.: 6.5 - 6.79
Type / Period: EA / no period listed
Spectrum: A0

Name: NSV 15601, HD 17891, HIP 13512
RA / Dec: 02h 54m 00.98s / +47° 09' 39.2"
Magnitude, Max. - Min.: 6.78 - < 7.5
Type / Period: VAR: / no period listed
Spectrum: B9

Name: NSV 15600, HD 17818, HIP 13462
RA / Dec: 02h 53m 21.07s / +48° 34' 11.8"
Magnitude, Max. - Min.: 6.17 - 6.55
Type / Period: VAR: / no period listed
Spectrum: G5Iab:

Dimmer than eBLM (Range > mv 0.3):

Name: NSV 15688, TYC 2873-716-1, BD +43 0719
RA / Dec: 03h 26m 52.72s / +44° 21' 50.7"
Magnitude, Max. - Min.: 9.1 - 10.3
Type / Period: no details listed
Spectrum: K0

Creating Asterisms: SALC 34 North

This is as good a time as any to document the process of working on a new search area location chart (SALC). Since the current SALC (#53 in Auriga) is rising a little too late these days I'm working on a new chart - SALC 34 (north) in Perseus.

I prefer working on rising SALCs since they are located in the darkest portion of Central Park's night sky ... the northeast.

The 1st night of observing (Mon., Oct. 17th) was under less than ideal conditions. High cirrus impacted the binocular limiting magnitude (BLM) by a few tenths of a magnitude for the 1st hour. The situation improved when the cloud cover started to dissipate.

When viewing through cirrus, stars of magnitude 8.6 and dimmer took some effort to see. Later on stars down to magnitude 8.8 - 8.9 were steadily seen without effort. The total number of stars examined for creating asterisms was 193. This is approximately half of the northern portion of SALC 34.

Time spent observing was 1h40m (9:20p-11:00p). A few minutes were spent talking to passersby about the night sky.

After noting the stars that are easily seen and the ones that took some effort I sketched in a preliminary set of asterisms. While viewing at the binoculars I'll sometimes just note that a star was easily seen by underlining it. Stars taking some effort to see are circled.

At home I create further connections based on what I remember seeing in the field and what appears to make the most sense.

Creating asterisms without sitting behind the binoculars doesn't seem to work even when knowing the BLM. I tried this with SALC 93 in Monoceros. After reviewing these asterisms in the field I needed to redo all of them.

From this chart I'll study the asterisms and revise connections whenever there's free time. Revisions are inevitable when I get back to the eyepieces.

After feeling comfortable with a preliminary version I'll layout the lines with pencil & straightedge. I'll copy these maps since they take time to create.

When I'm very comfortable with the figures I'll go to the desktop planetarium program Cartes du Ciel (CdC) and create an overlay which will become a permanent record of the asterisms. This overlay becomes a part of each chart I work with in the field. CdC makes the process of creating asterisms to display on a chart fairly easy after learning the 'way.'

From these charts I will hopefully develop a familiarity that will obviate the need for working with charts.

Central Park Observing - 17 Oct. 2005

Location: TotL - Central Park's Great Lawn (north end)
Date/time: Mon, 17 October 2005 (9:00p-11:25p)
Optics: 10x70 Fujinon's (mounted)
Conditions: winds variable: calm to 6 mph; temperature 55°-53°F; cloud cover: high thin cirrus for most the evening

Arrived at ~9:00p at the 'top of the lawn'. High cirrus covered the sky with patches of lighter cover in places. The brighter stars in Cassiopeia were visible including η Cas. The cloud cover didn't interfere much.

Since I was on my own at TotL I started nova hunting immediately. Tonight's task was to work on a new area of the sky since the current area I'm working on in Auriga is rising a bit too late for now - around 11:15p.

The new search area is half of SALC 34, the northern portion, which includes Mirfak and the surrounding Perseus OB3 Association. I'm cutting the SALCs in half in order to better represent them on paper. When printing stars to magnitude 9.0 a full SALC is very crowded on a sheet of 8.5 x 11".

The hunt started around 9:20p ending around 11:00p. A number of passersby stopped to chat. One couple asked about the 'upcoming' lunar eclipse. I had forgotten about this and showed them on the Palm that it already happened that morning on the 17th around 8:14am & was probably visible on the west coast. We talked about eclipses both lunar and solar and in the process her dog ran off along the path. When this was pointed out to her she said "that's OK, this was more interesting" then went off to fetch her pet!

Another couple on roller blades stopped by and the young woman asked to see something. I told her I wasn't looking at anything special and 'offered her the Moon.' She said 'that's what I was looking for!' She enjoyed a long drink at the eyepieces. Their names are Eric and Raina and they both know Derek Snow. Also, Claudia and John stopped by to chat and said to say hello to Team TotL.

For ~1h40m I focused on looking at patterns in Perseus to see what the new asterisms would be. I covered approximately half the region tallying ~200 stars. Approximately 10% of the stars fell into the category of taking some effort to see convincingly. This process of starting up a new search area is enjoyable and I spend the time comparing stars seen in the binoculars with the printed chart which goes down to magnitude 9.0. All the stars on the chart were seen including 16 additional ones. I'll check to see what the magnitude of the additional stars are in order to print these out. I didn't check to see if any were 'new'. The key to creating the asterisms is not to make things that look like something but to make sure the stars in each section make sense relative to each other. There are natural blank spaces around groups of stars which makes the task fairly easy. I hope to solidify the patterns in SALC 34(N) by the end of the weekend.

Reviewing the areas constantly should make covering these groups easier in the future. The large layout in time right now will hopefully pay off in the future.

There was one odd thing seen while observing near the area surrounding Mirfak. I noticed a change in brightness in the corner of my eye. When it happened again I swung the binoculars a bit to view what was going on. It was a tumbling satellite. It was moving from left to right and was visible in the binoculars even when it wasn't flashing. When it brightened it was obvious in the optics. Possibly 5th magnitude. The time between flashes was less than a minute. I didn't time them. This was seen shortly after setting up - around 10:00p-10:20p.

Objects observed with the 10x70's:

OPEN CLUSTERS:
• NGC 663 in Cassiopeia: star hopped from δ Cas (Ruchbah) to a 'water jar' looking asterism a little more than 2° northeast of Ruchbah. The cluster was small and very tight. At least three stars were resolved.
• M103 in Cassiopeia: fairly bright, small and elongated in the binoculars.

SOLAR SYSTEM:
• The Moon: I pointed the binoculars at the Moon for Raina but didn't look at the Moon myself. Before arriving in the park, at home, I took a long look at the just rising Moon and saw that the eastern libration was favorable as Peter has mentioned. Just southeast of the twin bright craters east of Tycho (one of them is called Stevinus) there was a large expanse of maria. I don't know the name of this region and will look it up tonight. It was located very close to the southeast limb. If anyone knows name of this portion of the Moon please drop me a line.

Field Research: 15 October 2005

Last night I attempted to test two things:

• How high can I view using mounted binoculars?
• When does a star take some effort to view it?

The first answer is less than 50° which is what I thought. This is the reason for placing an SALC season between an altitude of 30° & 50°. Anything higher than this, with a standard mount, is a strain on the neck.

I started the nova hunt, which was more like research, at midnight and ended shortly before the 1am curfew. I worked on four asterisms in SALC 53 in Auriga.

The number of stars viewed was 78 and 57 (73%) were deemed easily seen without having to expend any effort to pull them out from the background. The stars seen with a little effort totaled 21 (27%). The magnitude range for the second group was 8.6 to 9.3. For the first group there was consistency in 3 out of the 4 asterisms. The dimmest magnitude seen with ease appears to be 8.4-8.5. Some stars marked as easily seen fell into the mag. range for the 'seen with a little effort' group. These are possibly mislabeled magnitudes in the catalog.

Based on the above data I will print out charts down to mag. 9.0 and see if this works out.

Central Park Observing - 15 Oct. 2005

Location: TotL - Central Park's Great Lawn (north end)
Date/time: Sat-Sun, 15-16 Oct. 2005 (~10:30p-12:45a)
Optics: 10x70 Fujinon's (mounted); 8.5x42 Swarovski's
Observers: myself, Kin plus 8 passersby including George
Conditions: winds from the west from 7-9 m.p.h., temperature 59°-58°F

When I arrived at ~10:30p Kin was there speaking with another regular, George. Hearing snatches of conversation I could tell George was relating tales from his solo adventures across the globe.

After setting up the binoculars on the Pleiades both Kin and George enjoyed the view. Mars and the nearly full Moon respectively were placed in the binoculars as I was assembling the chair. George was thrilled with the view of the Moon calling it 'the gem of the sky'. He can Bogart optics like no other. A true connoisseur!

The night sky was finally clear after many days of overcast nights. Magnitude 4.8 stars were spotted easily but I didn't make an effort to do a true estimate of the limiting magnitude. More time than expected was spent showing the public and not looking for novae.

Objects observed with the 10x70's:

GLOBULAR CLUSTERS:

• M2 in Aquarius [mv 6.3]: spotted in the 8.5x42's and then picked up in the 10x70's. Kin was able to pick up the less than stellar glow. The star hop was made from β Aqr (Sadalsuud) [mv 2.9]. Three stars [mv 5.8-6.9] north of (above) Sadalsuud form a triangle whose base points in the general direction of M2. M2's distance from β Aqr is ~4.8°.

• M15 Great Pegasus Cluster [mv 6.0]: spotted easily in the 8.5x42's and much easier than M2. The star hop was from ε Pegasi (Enif) [mv 2.4]. A line from θ Pegasi (Baham, which is southeast of ε) [mv 3.5] to Enif leads directly to M15. The distance from Enif to M15 is ~4.2°. The stars immediately surrounding the globular cluster are close and bright making for a rich and recognizable field in the binocular's 5.3° field of view.

OPEN CLUSTERS:

• M45 in Taurus (The Pleiades): first object for the night. Enjoyed by all including a number of passersby. A group of three young people (2 girls and a guy) stopped by. One of the young ladies was more interested than her friends and stuck around to view as many objects as I could show her. She was impressed by all but was blown away by the number of stars seen in the Pleiades compared to what could be seen naked eye. She asked many times what was the most amazing thing I've ever seen in the night sky from Central Park and I wasn't able to give a definitive answer since all of it is pretty amazing to me. I called out a number events with 'Lunar Eclipse' heading the list.

• Hyades in Taurus: showed this to George and he was less than overwhelmed but still enjoyed looking at the view.

• Perseus OB Association (surrounding α Persei (Mirfak)): looked great in the 10x70's with each blue/white star perfectly formed in the optics. Showed this one to George also. Turns out he couldn't get enough of the Moon.

• M36 in Auriga: easily spotted in the binoculars below the 'Cheshire Cat'. Pointed this asterism out to Kin and he recognized it as a smiley face. He then easily picked it up in his 7x50's.

• M37 in Auriga: very dim. Dimmest object viewed and was not picked up by Kin. I star hopped to it starting at the False Kids (τ, ν & υ at the apex) which point to M37. An asterism of three stars near M37 form a 'T' with M37 as the upper left portion of the short arm. M37 is ~4.8° from the tip of the 'False Kids'. The observation was confirmed with Planetarium for the Palm. Very subtle.

SOLAR SYSTEM:

• Moon: a little more than a day from full. Showed to all who passed by. All were impressed by the view. I didn't look closely and didn't try to identify the craters showing up on the following limb.

• Uranus in Aquarius: star hopped to it from the western stars of the 'Water Jar' (π & γ Aqr [mv 4.4-4.7 & 3.9]) which point to θ Aqr (Ancha) [mv 4.2] to the south. From Ancha it's a short (~5°) walk ESE to Uranus. Five brightish stars surround the planet. Three form a long isoscoles triangle with Uranus just east of the apex. Uranus is the tip of a west pointing, less than isosceles, triangle which is ~1° wide.

• Neptune in Capricorn: found δ Cap (Deneb Algedi) [mv 2.9] to the lower left of the already spotted Sadalsuud (β Aqr). From here it was short ~9.1° hop through γ [mv 3.7], ι (iota) [mv 4.3] to θ [mv 4.1]. With θ Cap at the base of an elongated 'Keystone' Neptune is the right object on the narrow side of the trapezoid.

• Mars in Taurus: seen naked eye with a quick glimpse in the binoculars. Would have been nice to seen in the large scope.

OTHER OBJECTS:

• Alberio in Cygnus: double star easily split in the 10x70's. Showed to both Kin and George.

• 'Coat Hanger' (asterism in Vulpecula): the three bright stars in the head of the Eagle (Aquila) should roughly point to the 'Coat Hanger'. I scanned for it knowing it was inside the 'Summer Triangle' closest to Altair.

• M57: Ring Nebula in Lyra: This was the only object looked for and not seen. Kin asked whether I was able to see this object in the binoculars. I told him it would be tough but would look like a slightly out of focus star. Between β & γ Lyrae, closer to Sheliak (β Lyr) I could see a nearly equilateral triangle made up of stars from mag. 8.3-8.8 which point to M57, south of the triangle. Between the dim triangle and the wide binocular double (optical?) mags 7.7 & 8.1 an 8.7 mag star was seen but I couldn't pick up the nebula just southwest of this star. M57 at the time was ~23° above the horizon.

COMMENTS:

I was impressed by the effect the sidewalk astronmers at TotL, and elsewhere, had on the few people we met last night. Besides Kin & George three groups stopped by and each knew of the group in one way or another.

One the guys in the first pair asked if an astronomy club met at the top of the lawn. I said we did but we weren't a club, just a group of friends.

The young guy hanging with the two girls knew we observed in the area and I invited the interested young lady to visit us again especially when Saturn was visible before the 1 AM curfew.

Then a couple stopped by both taking a took at the Moon. The woman mentioned that she was in the park to view the Leonids on a cold November night around Central Park's Great Lawn and was really impressed by the event. I asked how she found out about the gathering, which she viewed in pajamas and a parka, and said she probably read about it somewhere. I was interested in talking to her more but the husband pulled them away after thanking us for the view of the Moon. Overall an excellent night.

The nova hunt was postponed until 12:00am which I'll write about in another post. It was nice that the sprinklers never activated!

Astronomical Almanacs for SALCs

The following charts graphically show when a section of the sky is above a certain altitude (i.e. 30 & 50 degrees above either horizon). The thick black line shows when the area is transiting the meridian. SALCs are Search Area Location Charts sectioning off areas of the Milky Way used for nova hunting.

Overlaying the three twilights will clearly show when the area is visible in the evening after astronomical twilight and before Central Park closes at 1:00 AM.

The pink upright lines represent the beginning of at least 1 hour of viewing time before the park closes or when the area is between 30° & 50° shortly after astronomical twilight. This is considered a 'season' and exists both when the area is rising and when it is setting.

[Image] SALC 89 in Aquila
Seasons for this region:
• Rising: Jun. 1st (midnight) - Jul. 13th (10:27p)
• Setting: Aug. 15th (midnight) - Nov. 15th (6:12p)

[Image] SALC 34 (north) in Perseus
Seasons for this region:
• Rising: Aug. 30th (midnight) - Nov. 28th (6:07p)
• Setting: Jan. 6th (midnight) - Mar. 26th (7:47p)

[Image] SALC 53 in Auriga
Seasons for this region:
• Rising: Oct. 9th (midnight) - Dec. 29th (6:15p)
• Setting: Feb. 1st (midnight) - Apr. 10th (9:10p)

[Image] SALC 93 in Monoceros
Seasons for this region:
• Rising: Nov. 6th (midnight) - Feb. 10th (6:54p)
• Setting: Jan. 20th (midnight) - Apr. 9th (9:04p)
• Daily double: Jan. 20th (midnight) - Feb. 10th (6:54p)

(In order to view the chart properly you may need to hover the cursor over lower right corner of the image to 'Expand to regular size')

A Year of Twilight: A Graphical View

The graphic below will be used to create charts showing when a celestial object is above a certain altitude (i.e. 30 & 50 degrees above either horizon). The thick black line shows when the star is transiting the meridian.

Overlaying the three twilights shows when the star is 'at altitude'.

[Image] Twilight Chart
[Image] γ Cas - Transit & 30°/50° Alt.

Definitions:

• Civil Twilight (outside lines) is defined to begin in the morning, and to end in the evening when the center of the Sun is geometrically 6 degrees below the horizon. This is the limit at which twilight illumination is sufficient, under good weather conditions, for terrestrial objects to be clearly distinguished; at the beginning of morning civil twilight, or end of evening civil twilight, the horizon is clearly defined and the brightest stars are visible under good atmospheric conditions in the absence of moonlight or other illumination. In the morning before the beginning of civil twilight and in the evening after the end of civil twilight, artificial illumination is normally required to carry on ordinary outdoor activities. Complete darkness, however, ends sometime prior to the beginning of morning civil twilight and begins sometime after the end of evening civil twilight.

• Nautical Twilight (middle lines) is defined to begin in the morning, and to end in the evening, when the center of the sun is geometrically 12 degrees below the horizon. At the beginning or end of nautical twilight, under good atmospheric conditions and in the absence of other illumination, general outlines of ground objects may be distinguishable, but detailed outdoor operations are not possible, and the horizon is indistinct.

• Astronomical Twilight (inside lines) is defined to begin in the morning, and to end in the evening when the center of the Sun is geometrically 18 degrees below the horizon. Before the beginning of astronomical twilight in the morning and after the end of astronomical twilight in the evening the Sun does not contribute to sky illumination; for a considerable interval after the beginning of morning twilight and before the end of evening twilight, sky illumination is so faint that it is practically imperceptible.

Definitions from 'U.S. Naval Observatory: Rise, Set, and Twilight Definitions'.

Naked Eye Limiting Magnitude Charts

Attached is a naked eye limiting magnitude (NELM) chart for Cassiopeia. The details on how it was processed in both SkyMap Pro and Paint Shop Pro are included.

[Image] NELM Cassiopeia mv 4.8 - 5.6

SkyMap Pro:
Constellations > General: Figures & Boundaries
Limiting magnitude: 5.6 (Proper Names only)
Stars > Display: Lim. mag 5.6 | Display Magnitude 0 |Dot size 10/2
Stars > Labels: Proper Names (all stars)
Stars > Options: Mark double stars with horizontal line (off)
Stars > Options: Mark variable stars w/hollow symbol (label check)
Coordinate grids: Scale line (on)
File > Prefs > Fonts > Screen: Star proper name (9pt)
File > Prefs > Fonts > Screen: Constellation name (12pt)
File > Prefs > Fonts > Screen: Compass (8pt)
File > Save as Picture: 650 x 424 pixels (Bitmap)

Paint Shop Pro:
Image: Adjust > Brightness & Contrast > Threshold (1)
- Adjust > Negative Image
Font: Bayer letters (Symbol 12 pt, Bold)
- Magnitudes (Trebuchet MS 9 pt, Bold, Underline)
- Labels unrelated to Bayer letters (Trebuchet MS 8 pt)
File > Save as: Windows or OS/2 Bitmap
Filesize: 38K

Image Formats: AW Persei

Could you do me a favor and view the images on the screen & print them out and let me know what you think? Click on 'Click for more ... ' below. The original's are the color images. The black & white's are processed to convert color to white on black and then I create a negative.

Thanks!

[image: b&w] SALC 53 'Dbl Peaked Triangle' w/AW Per

Font = Trebuchet MS regular 9pt
Star size: 7/1
Display Magnitude: 0
Mark double stars with horizontal line: off
Filetype/size = Bitmap reduced to 2 colors (1 bit)/36K
Processed = Adj > Threshold (1) Adj. > Negative Image

Changing Skies: 3 Oct 2005

On the evening of October 3rd I noticed the variable AW Persei, in the nova search area SALC 53, was dimmer than usual. Search Area Location Chart (SALC) 53 lies wholely inside Auriga. Two asterisms extend slightly beyond Auriga's border. One of the them, the 'Double Peaked Triangle', extends into Perseus where the variable is located.

On this night I was reviewing some asterisms from my north facing window on the Upper East Side. Shortly after scanning the area I saw a problem with the figure's outline. One of the peaks was dimmer than usual. From my previous research on this area I remembered that AW Persei was in this section of the sky. A quick check confirmed this was AW Persei.

This is a Classical Cepheid variable star with a period of 6.463589 days. Maximum brightness is magnitude 7.04. Minimum is magnitude 7.89. I haven't made a variable star estimate yet so all I could say about the brightness (sometime before midnight) was that it was noticably dimmer than 'usual' -- possibly magnitude 7.5 or fainter. The optics used were a pair of 8.5x42's.

It was a nice boost in confidence to be able to clearly see, within a matter of seconds, that something was 'up' in a familiar area of the sky. When nova hunting, I'm still referring to charts of asterisms and noting the stars I've seen. My hope is to acquire a knowledge of the search areas so I can scan the skies with a pair of tripod mounted binoculars without having to rely on printed charts. This find was made without referring to charts since I was only reviewing some of the more familiar areas in this section of the sky.

1st Night: '05 Fall Season

Tonight I arrived at TotL (northeast corner of the Great Lawn in Central Park) at 11:30p with Peter, Kin and Charlie already observing.

Nova hunting started at 11:55p and was interrupted by the lawn sprinklers going off at 12:05a. Around 12:30a the sprinklers ceased. Even with a light wind the mist drifted over our equipment. Lots of maneuvering to get optics onto dry ground. An officer in an SUV stopped by at 12:50a to remind us that the park was closing at 1:00a. Peter and I stayed with optics packed until nearly 2:30a observing and chatting. The officer never returned.

The sky was clear and my attention was on the northeast portion of the sky focusing on Auriga. A check of the naked eye limiting magnitude (NELM) from my apartment window on the Upper East Side was ~4.8. From the park I reached the same limit. Stars used for NELM were HIP 4151 (HD 5015) mag. 4.8 between γ Cas and κ Cas. Also seen was υ1 Cas mag 4.8 between γ Cas and η Cas (Achird). This is dimmer than υ2 Cas. Relating NELM to binocular's limiting magnitude (BLM) will be an ongoing project.

[image: b&w] NELM Cassiopeia mv 4.8 - 5.6

The optics used tonight were a pair of Fujinon 10x70's. They reached to at least magnitude 9.5. Something I need to resolve for this survey is how deeply should I search in order to cover as much ground as quickly as possible with a decent chance of finding a nova. Determining how much brighter than the BLM is the key. What I'll attempt to do next time out is to bin the stars seen in the 'bins' based on how difficult they are to see. I'm thinking of 5 groupings but will finalize this in the field:

1 - obvious even with sunglasses on
3 - dimmest star seen with no effort
5 - seen after searching for an extended period

I've decided for now to keep this binary and will work with 2 groups:

1 - star seen with no effort
2 - seen after searching for a short period

1-2 Oct 2005: Time spent nova hunting ~30 minutes from 11:55p-12:55a.

Dimmest stars seen in 2 asterisms (Double Peaked Triangle & One-armed Stickman) in SALC 53:

HD 280232 (v mag 9.5)
TYC 2894-1223-1 -- Star in double system
Sources: PtfP 9.53; Tycho-2 VTmag 9.593 (err 0.029); GSC-2.2 Bjmag 10.30 (err 0.04) / Vmag 9.59 (err 0.03); GSC Pmag 9.38 (err 0.40); SAO Pmag 10.0 / Vmag 8.9; AGK3 Pmag 10.0; HD Ptm 10.0; BD mag 9.0

HD 30896 (v mag 9.3)
TYC 2399-600-1 -- Star
Sources: PtfP 9.28; Tycho-2 VTmag 9.31 (err 0.028); GSC Pmag 9.26 (err 0.23); AGK3 Pmag 9.3; SAO Pmag 9.3 / Vmag 8.7; HD Ptm 9.00; BD mag 8.8

HD 277396 (v mag 9.3)
TYC 2899-1549-1 -- Star
Sources: PtfP 9.26; Tycho-2 VTmag 9.433 (err 0.021); GSC & GSC-ACT Pmag 8.76 (err 0.40); SAO Pmag 10.8 / Vmag 8.8; AGK3 Pmag 10.8; HD Mag 10.8; BD mag 9.0; 2MASS Bmag 10.91 / Rmag 9.26; GSC-2.2 Bjmag 11.36 / Vmag 9.43; USNO-B1.0 B1mag 11.19, B2mag 10.09 / R1mag 8.45, R2mag 8.38; USNO-A2.0 Bmag 11.6 / Rmag 8.1

Catalogs:
2MASS All-Sky Catalog of Point Sources [2mass]
AGK3 Catalogue (Dieckvoss, Heckmann 1975) [i/61b]
BD: Bonner Durchmusterung (Argelander 1859-1903) [i/122]
GCVS: Gen. Cat. of Variable Stars 4.2 (Vol. I-III) [ii/250]
GSC: HST Guide Star Cat., ver. 1.2 (Lasker+ 1996) [i/254]
GSC-2.2 Catalogue (STScI, 2001) [GSC-2.2, i/271]
GSC-ACT: HST GSC, ver. GSC-ACT (Lasker+ 1996-99) [gsc-act]
HD: HDE (H. Draper) Charts: p.p.m. (Nesterov+ 1995) [iii/182]
PftP: Planetarium for the Palm, version 2.4beta4c
SAO: Smithsonian Astrophysical Observatory Star Cat. [i/131a]
Tycho-2 Catalogue (Hog+ 2000) [i/259]
UCAC2 Catalogue (Zacharias+ 2003) [i/289]
USNO-A2.0 Catalogue (Monet+ 1998) [i/252]
USNO-B1.0 Catalog (Monet+ 2003) [i/284]

The Greek alphabet: α alpha, β beta, γ gamma, δ delta, ε epsilon, ζ zeta, η eta, θ theta, ι iota, κ kappa, λ lambda, μ mu, ν nu, ξ xi, ο omicron, π pi, ρ rho, σ sigma, τ tau, υ upsilon, φ phi, χ chi, ψ psi, ω omega

Summaries thru Feb. 2005

Table of first set of observations. Twenty-two sessions focused on 3 Search Area Location Charts (SALC). The first in Aquila (#89), the next in Auriga (#53) and the most recent in Monoceros (#93).

SALC Date & Tot. Time  BLM    Optics
 93  2005/02/19 3h25m  8.6 Fujinon 7x50
 93  2005/02/05 3h55m  8.6 Fujinon 7x50
 93  2005/01/23 1h15m  8.5 Fujinon 7x50
 93  2005/01/18 0h50m ~8.5 Fujinon 7x50
 53  2005/01/15 0h50m ~8.5 Fujinon 7x50
 53  2004/12/27 1h00m ~8.5 Fujinon 7x50
 53  2004/12/27 0h30m ~8.5 Fujinon 7x50
 93  2004/12/27 1h00m ~8.5 Fujinon 7x50
 93  2004/12/25 1h05m ~8.5 Fujinon 7x50
 53  2004/12/20 2h10m ~8.5 Fujinon 7x50
 53  2004/12/08 2h25m ~8.5 Fujinon 7x50
 53  2004/12/05 1h45m ~8.5 Fujinon 7x50
 53  2004/12/04 0h15m ~8.5 Fujinon 7x50
 53  2004/12/03 1h55m ~8.5 Fujinon 7x50
 53  2004/12/02 1h50m ~8.5 Fujinon 7x50
 53  2004/11/29 0h40m ~8.5 Fujinon 7x50
 89  2004/11/26 0h20m ~8.5 Fujinon 7x50
 53  2004/11/26 1h30m ~8.5 Fujinon 7x50
 89  2004/11/15 1h00m ~8.5 Fujinon 7x50
 89  2004/11/13 1h40m ~8.5 Fujinon 7x50
 89  2004/11/09 1h15m ~8.5 Fujinon 7x50
 89  2004/11/08 1h20m ~8.5 Fujinon 7x50
     ----------------------------------
     Total nights: 22
     Total time:   31h55m