NGC/IC Project Restoration Effort
(This is a very very beta version)
NGC5861
Basic Information
Location and Magnitude
Right Ascension: 15:9:16.2
Declination: -11:19:20
Constellation: LIB
Visual Magnitude: 11.6
Historic Information
Discoverer: Herschel W.
Year of discovery: 1784
Discovery aperture: 18.7
Observational
Summary description: F, L, E, r
Sub-type: SBc
Corwin's Notes
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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
3098144. 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
only appears on the DSS2 blue images, so is an artifact of some sort.
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.
Steve's Notes
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NGC 5861
13.1" (7/5/83): fairly large, very diffuse, elongated 3:2 NW-SE, fairly low even surface brightness. Located 2.5' NNE of a mag 10.5 star. Forms a pair with NGC 5858 9.5' NW.