210103 - M81 "Bode's" + M82 "Cigar" galaxies

click image to enlarge

ASTRO:
     type=2x Spiral galaxies,
     const=Ursa Major
     mag=6.9
     dist=12 M ly
     size(Bode's)=92 ly
IMAGE:
     location=EB Driveway
     BrtlCls=4
     exposure=DSLR OSC: 39x180s (2.0h), ISO1600
EQUIPMENT:
     camera=Nikon D90 (stk)
     optics=ES102, F=714mm, f/7
     filter=Optolong L-Pro LPS
     mount=Celestron AVX
     guiding=Orion 60x240mm, ZWO ASi224MC
SOFTWARE:
     acquisition=Stellarium, APT, PHD2,
     processing=DSS, PhotoshopCC

On the left and surrounded by spiral arms is spiral galaxy M81; also known as Bode's Galaxy.  On the right and marked by red gas and dust clouds is irregular galaxy M82; often named the Cigar Galaxy due to its apparent shape as viewed by us from here on Earth.  This stunning vista shows these two mammoth galaxies locked in a gravitational dance, as they have been for the past billion years. The gravity from each galaxy dramatically affects the other as they dance past each other during each hundred million year long movement.  Astronomers theorize that in their last pass, M82's gravity likely raised density waves rippling around M81, resulting in the richness of M81's spiral arms.  But simultaneously, M81 left M82 with violent star forming regions and colliding gas clouds so energetic the galaxy glows in X-rays.  In a few billion years the two are expected to merge; and, only one galaxy will remain.

M81 and M82 are considered ideal for viewing using binoculars and small telescopes.  The two objects are generally not observable to the unaided eye, although highly experienced amateur astronomers may be able to see M81 under exceptional observing conditions and with a very dark sky.  Telescopes with apertures of 8 inches (20 cm) or larger are needed to observe structures in the galaxy.

Look for images in this collection: "220406  M82 Cigar Galaxy" and "220427  M81 Bode's Galaxy" for better individual detail and astronomical heritage.