Re: Question about M76


Paul
 

NGC 2371-72 was probably the most exciting new object I found in the last month. Enjoyable because I was able to find it from my backyard and because it took some work to see some detail.

I checked out the list of 16 Messier objects in the H400 list on wikipedia. I thought maybe they were the "tougher" Messiers, but doesn't seem so (M82 was among the first ten that I found on my own). Interesting that a eleven of them seem to be 'special' cases from Messier's list:

M104-110 - None of these were published as part of Messier's original list and were added in 20th century.

M102 - This is NGC 5866 in Draco, which replaced the mistake duplicate entry of M101. Some maintain that Messier did indeed intend for this galaxy to be his 102nd object.

M47, M48, M91 - All had positional errors in Messier's list. Despite this, it was definitely established that Messier observed and logged them.

For reference, the other five Messier objects in the H400 are M20, M33, M61, M76 and M82.

So, if you complete the Messiers, you already have 16 towards the H400 (looks like M76 is only included once, as NGC 651). Add the two-fer of NGC 2371-72 and you almost have 5% of them ;)

- Paul

--- In backbayastro@yahoogroups.com, "boba_fett_fan" <nickiwi2@...> wrote:

Then it's interesting that they give NGC 2371 and 2372 separate entries in the Herschel 400 list. Speaking of anomalies in the Herschel list, it's also curious that NGC 3628 (Leo Triplet) made it to the Herschel list, but M65 and M66 did not. There are 16 Messiers that made it to the Herschel list, so it wasn't like they were trying to avoid having them on the list.

-Nick Anderson

--- In backbayastro@yahoogroups.com, "Ted Forte" <twforte@> wrote:

I think it is quite well established that Messier 76 is a single object (a
bi-polar, or multi-polar planetary nebula). The NGC dual identification is
generally handled by the designation NGC 750-1. NGC 2371-2 in Gemini is a
similar example of a single object with a dual NGC designation. (For the
same reason - it looks like two objects).



Ted



From: backbayastro@yahoogroups.com [mailto:backbayastro@yahoogroups.com] On
Behalf Of boba_fett_fan
Sent: Thursday, December 29, 2011 6:34 AM
To: backbayastro@yahoogroups.com
Subject: [backbayastro] Question about M76





I just noticed that M76 (Little Dumbbell Nebula) has two NGC numbers. I was
curious and read up on how Herschel catalogued it as two objects because he
believed it to be two objects. What is today's consensus on it being two
objects? Which NGC number is to be used for the Herschel 400 list (or are
both used)?

-Nick Anderson

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