NGC 4395

Alt. Designations: NGC 4395
Object Type: barred spiral galaxy
Constellation: Canes Venatici
Distance: 14.6 mly
Right Ascension: 12h 25m 48.8s
Declination: +33° 32´ 48"
Visual Magnitude: 10
Apparent Dimension: 13.2´ X 11.0´
Best Month To View: Apr

NGC 4395 is a low surface brightness spiral galaxy with a halo that is about 8′ in diameter. It has several wide areas of greater brightness running northwest to southeast. The one furthest southeast is the brightest. Three of the patches have their own NGC numbers: 4401, 4400, and 4399 running east to west. NGC 4395 is notable in that it contains one of the smallest supermassive black hole ever discovered. The central black hole has a mass of "only" 300,000 sun masses. The black hole was discovered in 1989, and had been judged to be between 55,000 and 65,000 sun masses. Recent estimates have thus quintupled the estimated size, but it is still far smaller than other black holes in its class. It is likely that is it so small because it has little material around it to add to its bulk. Indeed, stars are conspicuously absent in its immediate vicinity, and so it was "starved" down to that size or has never been able to fully grow, unlike most similar black holes.