M101 (Pinwheel Galaxy, NGC 5457)

Telescope: Planewave 20" CDK reflector, 2280mm FL with 0.66 Focal Reducer
Camera: FLI ProLine PL11002M, 4008 x 2672 pixels
Exposure: Lum: 8 x 4 minutes, Seeing 1.3" FWHM. Imaged to about mag 21.5
Location: Mayhill, New Mexico (Elevation 7380')
Image Center (J2000): RA 14h 03m 09s, Dec 54° 22' 03"
Image Size: 31' x 27'

Face-on asymmetrical spiral galaxy in Ursa Major. Apparent size 28' × 26', mag 7.5. Difficult visual object with low surface brightness mag 14.6. Bright patches in the spiral arms are star forming H-II regions. M101 has one of the highest number of identified H-II regions of any galaxy. Dark dust lanes visible in this image follow the spiral structure throughout the disk and well into the central region to the nucleus. Brightest H-II regions of M101 have been studied for many years. Dimmer H-II regions, many visible in this image, were cataloged in 1990. Limiting mag about 21.
Raw data for this image can be downloaded.


M101 (Pinwheel Galaxy, NGC 5457), Face-on asymmetrical spiral galaxy in Ursa Major. Apparent size 28' × 26', mag 7.5. Difficult visual object with low surface brightness mag 14.6. Bright patches in the spiral arms are star forming H-II regions. M101 has one of the highest number of identified H-II regions of any galaxy. Dark dust lanes visible in this image follow the spiral structure throughout the disk and well into the central region to the nucleus. Brightest H-II regions of M101 have been studied for many years. Dimmer H-II regions, many visible in this image, were cataloged in 1990. Limiting mag about 21., acquired with a remote telescope at Mayhill, New Mexico (Elevation 7380')

Object Label Identifier Notes
Galaxy G1 SDSS J140411.24+542518.6 mR=16.1
Galaxy G2 SDSS J140258.21+543328.5 mG=18.7
Galaxy G3 SDSS J140339.17+541503.4 mG=18.7
Galaxy NGC 5447 NGC 5447
Galaxy NGC 5449 NGC 5449
Galaxy NGC 5451 NGC 5451
Galaxy NGC 5453 NGC 5453
Galaxy NGC 5455 NGC 5455
Galaxy NGC 5461 NGC 5461
Galaxy NGC 5462 NGC 5462
HII Region HII regions 4 are marked.
Quasar Q1 z=3.257 SDSS J140354.57+543246.8 z=3.257 (11.7 Gyr), mG=20.3
Star S1 mG=21.3 SDSS J140308.81+543257.0 Reference mag star

Click on the image to display the plate solved image with annotations. 5' across M101 is about 30,000 light years.