40 Nights of the Herschel 400

by Craig Colvin

I've been taking advantage of the clear skies and moonless nights to get in some quality observing time in my backyard for the last three nights.

Here is a brief synopsis.

Sunday night - I picked up a 14" dobsonian loaner scope from SJAA late Saturday night so I wanted to compare it's views to my XT10. I just hopped around looking at Messier objects and a few planetary nebulas. Comparing each object between the two scopes. The views weren't as different as I expected so I'll take both to a darker site next week and continue the comparison.

Monday night - I decided to work on the Herschel 400 in Com. I've just recently started on the Herschel 400 list and had observed approximately 25 objects over 2 nights of observing. The skies where clear with a limiting magnitude of 5.3 (11 stars in Alp Crb, Gam Boo, Alp Boo triangle). I fairly easily observed 12 objects before the moon rose and called it a night. It was after the night of observing that I realized that if I looked at 10 Herschel's a night I could complete the entire Herschel 400 in 40 nights. Of course I'm going to have to spread these 40 nights over an entire year in order to catch them all.

Tuesday night - The sky was not quite as dark as the previous evening. Limiting magnitude was 4.9 which made it tough to see much detail. I struggled on the first object NGC4689. The Herschel catalog shows the magnitude as 10.9, the AP DSO catalog shows it has 11.5 and the MCG catalog lists it as 12.8, I would tend towards the 12.8 because it was the dimmest object I observed all night and I could just barely see it using averted vision. I was very discouraged by how hard it was to see and thought I might have to scrap my 10 Herschel's a night plan. But luckily the next on the list NGC4548 was easier to see and I realized I had just started with a particularly difficult one. I managed to finish off all of the Herschel's in Coma Berenices in 2 nights at a little over my pace of 10 a night. So perhaps it won't be 40 nights after all.