Tuesday, October 18, 2005

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:

• 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.

• 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.


Tag said...

Hi Ben,

Thanks for the comprehensive report of your efforts. Nice to watch - or read - how your development progresses. By your description it sounds as if SALC 34 is a new area for you. Also, does each SALC have as many stars, like the 200 that fall into to the "3" category that you described in First Night? (I'd be comfortable seeing you refer to this index regarding the stars difficulty.) I'm under the impression that your search areas all hug the Milky Way, so I wonder if the SALC gives you an indication of what part of the Milky Way you're observing?

Isn't the mare feature you saw Mare Australe? I was out again last night and saw it. It is not as obvious as the other limb maria and there is a pretty large crater, Lyot, inside its borders. I don't know if you noticed Mare Smythii - it was magnificent in a younger than one day "decrescent".

Good to hear that you had some company from the pedestrians. Sounds like there was the right amount traffic for you to get some work done.

c'ya peter

Ben C. said...


Yes. SALC 34 (north) is brand new.

BTW, I am looking to finalize the 'categories'. I will definitely be collapsing 1 and 3 and will probably end up with 1 (easily seen without any effort), 2 (seen with some effort but not obvious when casually looking at the area), 3 (*not* to be used since this would waste quite a lot of time - takes a great deal of effort to confirm the star exists).

Yes. All SALCs are wholely or partially filled with the Milky Way. For example:

- +70 to +90° are SALCs 1-4
- +60 to +70° are SALCs 5-12
- +50 to +60° are SALCs 13-22
- +40 to +50° are SALCs 23-38
- +30 to +40° are SALCs 39-56
- +20 to +30° are SALCs 57-72
- +10 to +20° are SALCs 73-84
- +0 to +10° are SALCs 85-94
- -10 to +0° are SALCs 95-103

... etc. etc.

Mare Australe! I wasn't sure whether it was on the E or W limb.

Traffic-wise it was an excellent night. The woman who lost sight of her dog for a minute remembered you as the guy with the big scope. She spread her hands like she was describing a fish she just landed.

See you around.