NGC/IC Project Restoration Effort

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NGC2903

 

Basic Information


Location and Magnitude


Right Ascension: 9:32:9.7
Declination: +21:29:57
Constellation: LEO
Visual Magnitude: 9.0

Historic Information


Discoverer: Herschel W.
Year of discovery: 1784
Discovery aperture: 18.7

Observational


Summary description: cB, vL, E, gmbM, r, sp of 2
Sub-type: SBbc

Corwin's Notes

===== NGC 2903. The nuclear region is patchy with several bright knots, probably star-forming HII regions, though generally refered to as "hot spots" in the literature. Rather than choose one as the "nucleus", I've taken the average of the five knots seen picked out by the 2MASS Point Source software within 12 arcsec of the brightest knot. This seems to be reasonably representative of the 15 accurate positions that I've collected up to May 2014. Also see NGC 2905 for the story on the northeastern arm of NGC 2903.

Steve's Notes

===== NGC 2903 48" (4/18/15): this superb spiral was observed at 375x. Several luminous patches are along the central bar, which trends SSW-NNE, including a patch (NGC 2905) at the northeast end near the beginning of the western spiral arm. Another patch is at the south end of the core with a third near the southern end of the bar where the outer eastern arm emanates. The outer western arm extends south for a length of ~4', just beyond the southern edge of the main body. The outer eastern arm emerges from the south end of the galaxy, curls east and shoots north. Although the surface brightness becomes quite low, the arm extends well beyond the main body for a total length of ~7'! At the northern end is a low surface brightness larger patch about 5.5' NE of center. The tips of the spiral arms are over 9' apart. 24" (2/22/14): excellent view at 200x and 375x. This beautiful barred spiral is sharply concentrated with an extremely bright, mottled core. A prominent central bar runs along the major axis, extending ~2'x0.4' SSW-NNE. The central bar is the brightest portion of an more oval, brighter central region, ~2.0'x1.0'. Just beyond the northeast end of the central bar is a bright, irregular "knot" (NGC 2905) where the northern spiral arm attaches. This arm bends sharply to the west (clockwise), but only curves for ~1' and quickly fades, as if it was angled towards us. A prominent arm (more cleanly separated from the central region) is attached at the south-southwest end of the bar where there is another brighter, irregular "knot". The southern arm bends east and then north, paralleling the orientation of the bar and extending as far north as the core, perhaps just beyond a mag 13.7 star 2' ESE of center. A darker dust lane separates this arm from the central region. 18" (2/14/10): beautiful view of this barred spiral at 175x. The galaxy extends 2:1 SSW-NNE, roughly 8'x4', with a slightly brighter bar running through the major axis. The center is sharply concentrated with a very bright clumpy core. At the SSW end of the main body a faint arm emerges and sweeps around to the east. Near the NNE end of the central bar is a brighter knot (NGC 2905) and beyond the knot is a fainter and less defined arm that curves around a short distance to the west. 17.5" (1/31/87): this is one of the brightest non-Messier galaxies. Very bright and large, elongated 5:2 SSW-NNE, 10'x4'. A very faint knot is involved on the NNE side 1.2' from center = NGC 2905. An extremely faint knot is also symmetrically placed opposite the core on the SW end 1.2' from center. The galaxy has a dusty, mottled appearance with knots and arcs easily visible with averted vision. 17.5" (3/23/85): a second knotty region is definitely visible on the SW edge. Lord Rosse mentions these two knots as "thickened regions". 13.1" (12/22/84): very bright, elongated bright core. Contains a very faint knot at the north end = NGC 2905. 8": bright, large, elongated, bright mottled core.