NGC 5861

History and Accurate Positions for the NGC/IC Objects (Corwin 2004)

NGC 5861. While preparing images for the NGC/IC Project's web pages, Bob Erdmann ran across a splendid edgewise galaxy in the DSS image of NGC 5861 just west-northwest of the bright spiral. Wondering what it was, Bob tried to find it in NED -- no luck, though it of course appears in the DSS images of N5861 there.

He had better luck with HyperLeda where the object carries the number LEDA 3xxxxxx. So why wasn't this in NED? It is a big object, with a major axis diameter nearly that of N5861 itself -- it should be there.

Digging further, I found that not only was it not in NED, I had not included it in ESGC, and I had not even made a note about it under the entry for the NGC galaxy! "Was I blind?!" I facetiously asked Bob in an email.

Well, it's clearly time to try another plate: the object does not appear on the DSS2 red plate, nor is it on the NEAT/SkyMorph plate. It also does not appear on the POSS1 red or blue prints, nor in any of the 2MASS scans. (It does appear on the "DSS2" blue images, but that is because HEASARC's SkyView uses DSS1 blue images for any part of the sky that does not yet have DSS2 blue coverage).

So, the spindle "galaxy" is a defect on the IIIa-J plate. Just to be accurate about this, the equatorial position is 15 09 07.06, -11 18 41.4 (J2000.0) or 15 06 23.60, -11 07 17.1 (B1950.0). Others have probably already stumbled across this -- or if they haven't, they certainly will.

One last note: it has a LEDA number because the LEDA group has included over a million non-stellar objects from GSC in HyperLeda. Most are galaxies, but the HyperLeda group has not been able to check them all. So, there are undoubtedly many more "galaxies" like this in HyperLeda.

This demonstrates a larger problem with all of the automated galaxy catalogues and surveys. All are "polluted" to a greater or lesser extent with non-galaxies. There are no sure methods for cleaning out the interlopers. Their percentage in any given catalogue is nevertheless small, ranging from about 10% in the APM galaxy catalogue, to less than 1% in the SDSS list with redshifts. Nevertheless, they are there, so we need to approach these big catalogues with some caution and considerable preparation.

Historical observations

William Herschel (c.1784)

Synonyms: H II-192

Discovered in 1784 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "pF, pL, slightly extended nearly along the meridian."

Published comments

Supernovae

A supernova erupted in this galaxy in 1971 (15.5v)

Helwan Obs. Bulletin No 22 (1921)

F, 3'x1.25', no nucleus; spiral with many alm.stell.condensations. Plate poor.

Sulentic & Tifft (1973)

(Sulentic and Tifft 1973) notes that this is a 12.5 mag galaxy. Their coded description reads S,BDDIFKNARM S NORTH ARM BROKEN UP.