Object of the Week, October 13, 2024 - From a lost epoch

Once upon a time, nebulae were a thing.

In the 40's and 50's of the 20th century a great many uncatalogued ones were photographed, studied and assigned proper designations. Even Boris Vorontsov-Vel'yaminov, best known for his catalogs of interacting galaxies and for a slew of planetaries, took a swing at it. In 1961 he published a brief paper titled New Planetary and Peculiar Gaseous Nebulae.

Truth be told, it is not a very impressive list. Of the 9 entries, 7 were previously cataloged and 1 is non-existent: nr. 7 was a fault on a 1953 blue plate at the position of the mag. 8.5 star SAO153249 in the constellation of Puppis.

That leaves us with only one nebula on the list that rightfully carries a Vorontsov-Vel'yaminov designation. That one is the paper's first entry and this week's OotW.

Please follow along as we go find it in SIMBAD. The designation used in the database is "[V61]". Entering this in the "by identifier" search window, the site comes up with known nebulae for nr.'s 2 (LBN 151.25+02.12) through 9 (Sharpless 2-71). First of all, nr. 2's proper designation ought to be Simeis 28, nr. 9 really is Minkowski 1-90. Let's just call that room for improvement, shall we..?

Now, how's about that nr. 1..? Plot the SIMBAD position of 01:46:42 +53d39m00s in Aladin Lite and... well... there ain't nothin' there. How come?

Back to VV's paper. The position is 01:43:30 +53d24m00s. Entering that in Aladin Lite still reveals nothing, but that is to be expected as it's an epoch B1900 position. VV's paper states, in the first paragraph of page 1: "The coordinates are referred to 1900.0". Let's convert that to J2000.0 shall we? That makes it 01:49:59 +53d53m51s. Back to Aladin and... would you look at that! That's one pretty little reflection nebula.

So what happened in SIMBAD? Let's take a closer look at the data presented for the object. There's the J2000.0 coordinate as noted above and there's a B1950 one, too: 01:43:28.2 +53d24m02s... that's pretty darn close to the coordinate Vorontsov-Vel'yaminov listed, but in a different epoch. Hmmm...

What happened here, is that the B1900 position of 01:43:30 +53d24m00s was listed on SIMBAD as a B1950 position instead, then converted to J2000.0 (01:46:42 +53d39m00s). That's where the error was made. B1950 to J2000.0, where it should have been B1900 to J2000.0.

This may have been one reason why this nebula has been overlooked and, to the best of my knowledge, not included on any starchart or in any publication that us amateur stargazers use to plan our observing runs. That, however, will change, soon.

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Click here to download the guide.

What does it look like in the eyepiece? I must admit I don't know, yet. Is there anyone who observed this nebula? It's plenty bright, that much is sure.

This is what Vorontsov-Vel'yaminov had to say about it:

Diffuse nebula. The main, southern, part is quite bright and is brighter in the blue than in H-alpha. This is unusual for diffuse nebulae. The bright part is shaped like a horseshoe, pointed toward the west. Its size is 1.3'×1.5'. A straight, broad, faint tail extends northward from it, and can be traced for more than 4'. The exciting star has not been identified. There is little absorption in the region.

The position (01:50:05 +53d54m25 J2000.0, to be exact) is in the constellation of Perseus, less than a degree from the border with Cassiopeia. To find it, either the mag. 5.5 star 1 Persei (one and a quarter degree to the north-northeast), or mag. 5 star 4 Persei (2 degrees to the east-northeast) provides for a good starting point.

In the vicinity:

VV' Neb 1 is on the east-southeastern edge of the large, much fainter emission nebula Lynds (LBN) 640, but that will be a tough one to grab. Just off to the west is the double star Espin 761 and only a tad further to the west-southwest is Espin 760.

Three quarters of a degree due east, there's a carbon star: V547 Persei, shining orange-red at about mag. 9. Nearest (relatively) bright DSO is the small, faint and poor open cluster NGC744, 2 degrees to the northeast.


Well, you know what to do: Give it a go, and be sure to report back!

Thanks for your research, Victor. I went to put it on my list of objects to observe last night when your mentioning LBN 640 brought back a memory. I then grabbed Stoyan's Interstellarum Deep Sky Atlas and found that right where Vorontsov-Vel'yaminov had discovered and published his nebula, Stoyan had it plotted as LBN 640. And I remembered seeing it in my 10-inch a few years ago due to stumbling upon it on the IDSA. So, I didn't reobserve it last evening. But now, the next day, I have yet to find the digital copy of my observation, so it looks like I'll be reobserving it after all!


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