Sunday, December 18, 2005

Central Park Observing - 17 Dec. 2005

Location: TotL - Central Park's Great Lawn (north end)
Date/time: Sat., 17 December 2005 (8:10p-9:00p)
Optics: 10x70 Fujinon's (mounted)
Conditions: winds W 6-7 mph, temp. 37-36°F

This was a short night in the park. Setup was completed at 8:20p after traveling for 40 minutes to the site. Clouds started rolling in from the west around 8:45p. Conditions were clear, cool with a predominantly west wind.

• Topics: SALC 53N; categories 1 & 2

Tonight I worked within SALC 53 North in Auriga. This section of the sky is +40° to +35° in declination and 5h40m to 5h00m in R.A. I've already created asterisms for this area using 7x50 Fujinon's. Now that the binocular limiting magnitude (BLM) has increased there is a need to create a new set of asterisms.

My task for the few minutes I had of clear sky was to bin the stars into the categories I mentioned in a previous post.

After looking at 52 stars in 3 asterisms the following was found:

Category 1: Obvious stars. These are bright enough to take no effort to see. Many would be visible while looking at them through a filter. There were 13 stars that fell into this category. The range for tonight with the 16.5 day old Moon nearby was mag. 5.1 – 6.9.

Category 2: Stars dimmer than cat. 1 taking little effort to see. These stars are steadily seen and need no effort pull out from the background glow. 39 stars fell into this category. The range for tonight was mag. 8.0 – 9.0.

There was a natural gap between the dimmest category 1 (mag. 6.9) and the brightest category 2 (mag. 8.0). This gap will narrow as the number of stars increase. It will be interesting to see where the line in the sand is drawn.


Number of stars seen:
• 52 during a 20 minute session.