Saturday, November 12, 2005

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!


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.