The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on spiral galaxy distanced 21 million light-years (six megaparsecs) away from Earth in the constellation Ursa Major. Discovered by Pierre Méchain on March 27, 1781, it was communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final entries.
M101 is a large galaxy, with a diameter of 170,000 light-years. By comparison, the Milky Way has a diameter of 100,000 light years. It has around a trillion stars, a little more than twice the number in the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small central bulge of about 3 billion solar masses.
M101 has a high population of H II regions, many of which are very large and bright. H II regions usually accompany the enormous clouds of high density molecular hydrogen gas contracting under their own gravitational force where stars form. H II regions are ionized by large numbers of extremely bright and hot young stars; those in M101 are capable of creating hot super-bubbles.
M101 is asymmetrical due to the tidal forces from interactions with its companion galaxies. These gravitational interactions compress interstellar hydrogen gas, which then triggers strong star formation activity in M101's spiral arms that can be detected in ultraviolet images.
Imaging telescopes or lenses: Takahashi FSQ130ED
Imaging cameras: QSI 6120i
Mounts: Takahashi EM 400 Temma 2M
Guiding telescopes or lenses: Takahashi FS60CB
Guiding cameras: QHY CCD QHY 5 II
Focal Extender / Reducer: None
Software: Sequence Generator Pro SGP (for capture) PHD 2 (guiding), Astro Pixel Processor & PixInsight,
Filters: Astrodon LRGB
Accessories: Robofocus Focuser, ATIK EFW3
Original Resolution: 2855 x 2020
Dates: 3rd Mar 2019 - 8th Mar 2019
Frames:
Astrodon L 96 x 5'
Astrodon R 30 x 5'
Astrodon G 30 x 5'
Astrodon B 30 x 5'
Total integration = 15.5 hours.
Center (RA, Dec):(210.824, 54.367)
Center (RA, hms):14h 03m 17.805s
Center (Dec, dms):+54° 22' 00.318"
Size:46.9 x 33.2 arcmin
Radius:0.479 deg
Pixel scale:0.986 arcsec/pixel
Orientation:Up is 180 degrees E of N
M101 is a large galaxy, with a diameter of 170,000 light-years. By comparison, the Milky Way has a diameter of 100,000 light years. It has around a trillion stars, a little more than twice the number in the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small central bulge of about 3 billion solar masses.
M101 has a high population of H II regions, many of which are very large and bright. H II regions usually accompany the enormous clouds of high density molecular hydrogen gas contracting under their own gravitational force where stars form. H II regions are ionized by large numbers of extremely bright and hot young stars; those in M101 are capable of creating hot super-bubbles.
M101 is asymmetrical due to the tidal forces from interactions with its companion galaxies. These gravitational interactions compress interstellar hydrogen gas, which then triggers strong star formation activity in M101's spiral arms that can be detected in ultraviolet images.
Imaging telescopes or lenses: Takahashi FSQ130ED
Imaging cameras: QSI 6120i
Mounts: Takahashi EM 400 Temma 2M
Guiding telescopes or lenses: Takahashi FS60CB
Guiding cameras: QHY CCD QHY 5 II
Focal Extender / Reducer: None
Software: Sequence Generator Pro SGP (for capture) PHD 2 (guiding), Astro Pixel Processor & PixInsight,
Filters: Astrodon LRGB
Accessories: Robofocus Focuser, ATIK EFW3
Original Resolution: 2855 x 2020
Dates: 3rd Mar 2019 - 8th Mar 2019
Frames:
Astrodon L 96 x 5'
Astrodon R 30 x 5'
Astrodon G 30 x 5'
Astrodon B 30 x 5'
Total integration = 15.5 hours.
Center (RA, Dec):(210.824, 54.367)
Center (RA, hms):14h 03m 17.805s
Center (Dec, dms):+54° 22' 00.318"
Size:46.9 x 33.2 arcmin
Radius:0.479 deg
Pixel scale:0.986 arcsec/pixel
Orientation:Up is 180 degrees E of N
Sky map
Annotated Image