LSB Galaxy NGC 4395

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About this Image

NGC 4395 is a low surface brightness (LSB) spiral galaxy with a halo that is about 10' in diameter. It has several star forming areas running northwest to southeast that are significantly brighter than the central bulge. 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.

NGC 4395 has been identified some years ago as the least luminous and nearest Seyfert galaxy known, based on its spectrum. It is about eight million light-years away in the direction of the constellation Canes Venatici (The Hunting Dogs).
A Seyfert galaxy is a class of nearby galaxy that has an extremely bright central region that often obscure the much dimmer stars in the surrounding disk. The nucleus gives off prodigious amounts of energy largely in the form of high-energy x-rays and gamma rays.

Most of the small scale objects in this image are faint background galaxies (mag 18-22) showing up in a filamentary structure, typically in yellowish color as obscured by intergalactic dust.

North is up left.

 


Technical Details

Optics

16" cassegrain in corrected secondary focus at f/10

Mount ASA DDM-85XL
Camera SBIG STX16803 at -30C, STX filter wheel
Filters Baader 65x65mm LRGB
Date April-May 2011
Location Wildon/Austria
Sky Conditions mag 5-5.5 sky, raw FWHM 1.7-2.5", temperature 10-17 C
Exposure L:R:G:B = 600:100:100:120 minutes (20-minute sub-exposures)
Programs used Autoslew
Maxim DL 5
CCDStack
Photoshop CS5