M 106 Galaxy Click on photo to return to 'Galaxies' Home
M 106 NGC4258
Dreyer description: Very bright, very large, very moderately extended 0°, abruptly brighter middle bright nucleus; = M106.
RA: 12h 18m 57.8s Dec: +47°18'16" (Epoch 2000)
Azm: 306°15'16" Alt: +74°31'01"
Size:18.6' x 7.3'
The bright Sb spiral galaxy M106 is perhaps about 21 to 25 million light years distant. It is receding at 537 km/sec. Sandage suspects it may be a member of the Ursa Major cloud, a loose agglomeration of galaxies. As its equatorial plane is similarly inclined to the line of sight, many features resemble what we know from the Andromeda galaxy M31. As Alan Sandage mentions in the Hubble Atlas of Galaxies, this orientation explains partly why the dust lanes are so prominent in this galaxy. They form a spiral pattern which can be traced well into its bright central region to the core. The spiral arms apparently end in bright blue knots. These knots are most probably young star clusters which are dominated by their very hot, brightest and most massive stars; the occurance of these hot stars indictes that these clusters cannot be very old, as such massive stars have only a short lifetime of a few million years. So the blue knots show us the regions of very recent star formation!
Following the spiral arms in the sense of rotation, and most conspicuous on the right of our image, is the yellowish remnant of an older spiral arm. The color of this arm indicates that its more massive stars have ceased to shine long ago, the color of the remaining ones sums up to the yellow-greenish appearance. The age of the stellar population in this fossil spiral arm is estimated by J.D. Wray to amount several hundred million years.
Dreyer description: Very faint, small, westward moderately extended, pretty abruptly brighter middle.
RA: 12h 17m 50.2s Dec: +47°24'37" (Epoch 2000)
Size: 3.0' x 1.1'
From M106: Angular separation: 00°13'06" Position angle: +299°07'
16" F/4.87 Newtonian , ST-8XE, CFW8 07/07/05 Temp. = -8 C
Processing: CCDops; DDP; MaxIm; align, color combine; CCDsharp; PhotoImpact; final touchup