Tuesday, November 08, 2005

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.

1 Comment:

Tag said...

Next to seeing M1, the waiting & talking ranks a close second to the night's event.

Ouch! 60° & 70° looking up with bins sounds very straining, even when sitting down.