Observing Report 15 Feb 2001

Monoceros

by Robert Leyland


It's a couple of days overdue, but since the weather is so lousy, it gives me a chance to catch up on my reports, however short.

Observer Robert Leyland
Date 15 Feb 2001
Time 2130-2330 PST (1330-1530 UT)
Location Novato CA. 38N 122.6W Elev 500'
Weather 5°C Temp, 90% Hum
Seeing LM 5.0, moderate steadiness
Visibility Bay Area light dome obscures horizon to the east
Equipment 8" F6 Dobsonian, Pentax XL eyepieces

I had the telescope out early in the evening to allow it to come to temperature, but didn't get out until relatively late. The seeing was not the greatest, this was the second clear day after a storm had rolled through, and the forecasts for upcoming days were not good. So I took what time I could get for my stellar photon deprived eyes. Checking some "standard" sights first, both the E and F stars were visible in the trapezium at 170x. However, with admittedly limited dark adaption, the Flame Nebula was not visible.

In keeping with my constellation-by-constellation touring, tonights area of interest is Monoceros.

Starting with the easy double star Epsilon Mon, which appears as two distinctly yellow stars with the primary being more than twice as bright as its companion.

Scanning in the finder, the central cluster of the Rosette Nebula really stands out in the same field of view as Eps.Mon, at 55x the cluster shows a dozen bright stars and maybe 50+ dim stars. Surrounding the cluster is a greyish darkness, that is easy to see on the E side. This greyness blocks/reduces the average star count as makes the region look almost unfocussed, almost as though someone had smudged the stars around the cluster. A UHC filter causes the nebula to leap into view, it is really extensive and overflows the view, even at 30x, in all directions. (An OII filter shows a little more brightness but does not markedly improve the view). Wispy details flow outward in several directions, and at times give the nebula a fuzzy U-shape. Well worth revisiting.

The pretty blue multiple star Beta Mon is next up. At 30x it shows as an easy double, moving higher the brighter "star" resolves into two stars. Each star is of almost equal brightness, and that electric arc blue color. The close pair might make a good test of telescope optics, since poor baffling would flare the stars together.

At the center of a triangle formed by Beta Mon, 7 Mon, and Gamma Mon (itself a pretty yellow star) is a faint open cluster NGC 2215. It is a fairly evenly distributed smattering of stars varying from faint to very faint occupying a quite round area.

The open clusters NGC 2225/6 elude me, the location from the star chart is clear, but the clusters are not.

More easily found are NGC 2219 and 2232, as a loose assortment of bright stars with numerous "milky way" clusterings providing a surrounding backdrop.

Open cluster NGC 2236 was hard to find, I'm not positive I it properly identified. It shows as a very faint patch of "glowing" at the right place by the chart, but individual stars are not resolvable.