Spiral Galaxy in Virgo

Uploaded 3/25/02

M61 is fascinating with its angular spiral arms that are rich in star forming blue regions and pink HII clouds. At 10.2 magnitude, this galaxy is very bright and we can see plenty of detail in its core. Classed as an SBc spiral, the yellow internal core exhibits dark bar dust lanes that are inside a polygon shaped zone in the heart of the galaxy come off tangent to the core rather than opposing. This is classic of a barred spiral. The size of this large object is 6.5 arcmins max, and it is face on at an inclination of only 1 degree.

Other galaxies in the field include MAC1221+0431 a very reddened spiral in the left outermost arm of M61, and to the upper right the larger object is MAC 1221+0423, a 17.0 magnitude spiral that is only .4 arcmins long. This is a much shorter exposure than I usually take, I was only able to get in 80 minutes of data here, because the scope was hitting the wall in the observatory being so far past the meridian!

Instrument:  12.5" f/5 Home made Newtonian
Platform:  Astrophysics 1200 QMD
CCD Camera:  SBIG ST7E w/Enhanced Cooling
Exposure:  LRGB = 50:10:10:17 (RGB Binned 2x2)
Filters:  RGB Tricolor
Location:  Payson, Arizona
Elevation:  5150 ft.
Sky:  Seeing FMHW = 2.3 arcsec, Transparency 8/10
Outside Temperature:  10 C
CCD Temperature:  -25 C
Processing:  Maxim DL, Photoshop, AIP4WIN, PW Pro.




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