Object of the Week, June 21, 2020 - Sancho's Object in Draco

[FaintFuzzies]

Object of the Week – Sancho’s Object (MAC 1510+5810 and MAC+5810A)
RA: 15 10 17 Dec: +58 10 39
Size: 0.5 x 0.4’ Mag: 16.0v
Const: Draco

Going through some of my favorite lists, this time I choose to look through Larry Mitchell’s Advanced Observing Programs for the Texas Star Party. This object is from the “2002 Interactions” list. Look here if interested.

Larry Mitchell is a well-known observer from Texas. He brings his 36” Obsession Telescope to TSP every year. There were only 4 of these built by Kriege at Obsession Telescopes. Starting in 2000, he produced an annual advanced observing list to encourage deep sky observers to push themselves to the limit and give the Advanced Observing Program a shot. It is a fun list and it definitely helped many visual observers to improve their craft. If an observer observes at least 20 objects from the list, they would get a cool pin from Larry. A few examples are below.

TSP Pinsa.jpg

He hangs out with folks like Barbara Wilson, Bill Christianson, Bill Chandler, Jose Sancho, etc. I’m sure that there are many others, their names escapes me. During one of the MegaStar updates, Jose Sancho independently discovered this galaxy pair, thus was named “Sancho’s Object” by Larry (I think).

From Larry’s notes in 2002. “It was named for Jose and Susan Sancho, who are two of the finest visual astronomers anywhere on the planet. These interacting galaxies were listed in a 1998 Astrophysical Journal article as SBSG 1509+583, for the Second Byurakan Survey of Galaxies, named for the Astrophysical Observatory in Armenia. The observatory also completed a study of “blue” (Markarian type) stars (SBSS). Since this object is also a strong emitter of infrared light, it also goes by the name of IRAS F15090+5821. Everyone who successfully observes Sancho’s object will belong to a very select handful of people who have ever visually seen this object glowing faintly at 16.5 magnitude and at a distance of nearly half billion light years away.” Keep in mind that this was written nearly 20 years ago, so I think quite a few deep sky hounds may have seen this object. I just thought it was pretty cool.

My latest observation of this galaxy pair was back in 2010 in the high Sierras at about 5,400 feet above sea level.

22” at 383 and 460x - This object consists of two very close interacting neighbors. MAC 1510+5810 is a considerably bright 3:1 elongated glow. PA = 150 and 0.3’ long. MAC 1510+5810A is a considerably bright round glow with high surface brightness. They were separated at 383 and 460x at about 15” apart. A bright mag 12.0 star lies 0.6’ due west of the pair. This pair appears brighter than the listed magnitude, closer to 15.0.

Sanchos Object.jpeg
Image from the Sloan Digital Sky Survey

As always, give it a go and let us know.

[Uwe Glahn]

Nice small pair Alvin.

sketch: 27", 586x, NELM 6m5+, Seeing III
Sancho.jpg
home

[obrazell]

If you don't have the Megastar program which is the only place the MAC catalogue exists the pair is also known as LEDA 3136298, at least the brighter one is.

Owen

[Jimi Lowrey]

Nice small pair Alvin.

sketch: 27", 586x, NELM 6m5+, Seeing III
Sancho.jpg
home

Nice drawing Uwe it is very realistic and looks very much like the View in my scope.

[Steve Gottlieb]

Here's my observation through an 18" at the 2010 Golden State Star Party. It was an excellent challenge object and was just resolved.

18" f/4.3 at 300x: Sancho's Object is a very close, very small pair of galaxies (edge-on and elliptical). At 300x, the combined glow was faintly visible, but resolving the pair was difficult. With concentrated viewing, the eastern component (LEDA 2816139) was extremely faint, very elongated 3:1 NW-SE, ~15"x5". Attached at the west side was a very faint and small "knot" (LEDA 3136298), perhaps 5" diameter. Located just 40" E of a mag 12 star and forms the northern vertex of an isosceles triange with two mag 10.5-11 stars 3' S and 3' SE.

[KidOrion]

If you don't have the Megastar program which is the only place the MAC catalogue exists the pair is also known as LEDA 3136298, at least the brighter one is.

Owen

And Sky Safari has one/both of them listed as PGC 3136298.

[FaintFuzzies]

Nice sketch Uwe! It is almost what I saw through the eyepiece of my 22".

And good observation Steve. I saw it the month before 2010 GSSP. Maybe you should try again with your 24".

[KidOrion]

I observed this object last night in 21.73 skies (7 S, 7 T)with a 20" f/5 Dob. At 181x, it was fairly easily spotted, but the two galaxies were not separable (duh). The core of MAC 1510+5810A was quite apparent even at this low power. At 363x, the edge-on galaxy was quite difficult and fleeting, but could be held briefly in direct vision.

[obrazell]

I believe the PGC (principal Galaxy Catalogue) and LEDA (Lyon Extragalactic Database) are the same thing, although Steve could perhaps enlighten us on this. I am not sure if these are dynamic databases or snapshots at a given time.

Owen

[wvreeven]

The PGC (Principal Galaxy Catalog) was a catalog that originally was published in 1989 which was renamed to LEDA (Lyon-Meudon Extragalactic Database) and expanded in 2003. LEDA was known as HyperLEDA for a long time but generally is referred to as LEDA now. According to the HyperLEDA website "HyperLEDA (Makarov et al. 2014) takes its roots in the Lyon-Meudon Extragalactic database (Paturel et al. 1988, LEDA), which was created in 1983, and in Hypercat, which started as the observational catalogue on kinematics of early-type galaxies (Prugniel & Simien 1996). These databases were joined toghether in 2000. Historically, the LEDA database was used for preparation of the Third Reference Catalogue of Bright Galaxies (de Vaucouleurs et al. 1991, RC3). "

[Steve Gottlieb]

LEDA is an extension of PGC and they adopted the same numbering for the original 73197 objects in the PGC. In professional papers (as well as NED), you'll generally see these objects prefixed by PGC, while the millions of higher numbers, starting at 73198 and running into the 3 millions, prefixed by LEDA.

For example, here's LEDA 3191684 in NED. But HyperLEDA doesn't make this distinction and lists this 19th magnitude galaxy as PGC 3191684.

So, in practice the usage of PGC and LEDA is interchangeable, though for historical reasons I prefer PGC for the original database.

[KidOrion]

[Carson] I did not know that. Thank you! [/Carson]