Hemisphere:  Northern  ·  Contains:  Bode's nebulae  ·  M 81  ·  NGC 3031
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M81 Bode's Galaxy, 


M81 Bode's Galaxy
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M81 Bode's Galaxy

Technical card

Imaging telescopes or lenses: Meade LX200 12" f/10

Imaging cameras: Atik 383L+ mono

Mounts: iOptron CEM 120

Guiding telescopes or lenses: Meade LX200 12" f/10

Guiding cameras: Lodestar

Focal reducers: Starizona SCT Corrector f/7.5

Software: PixInsight  ·  Sequence Generator Pro  ·  PHD guiding  ·  Dithering

Filters: Astronomik L 1.25" Type IIc  ·  Astronomik B 1.25" Type IIc  ·  Astronomik G 1.25" Type IIc  ·  Astronomik R 1.25" Type IIc  ·  Astronomik Ha 12nm 1.25"

Accessory: Hutech Mitsuboshi OAG5 Guider  ·  Atik EFW2 Filter Wheel  ·  Starizona MicroTouch Autofocuser

Dates:May 13, 2019May 14, 2019May 16, 2019June 12, 2019June 13, 2019June 14, 2019June 17, 2019June 20, 2019June 21, 2019

Astronomik B 1.25" Type IIc: 20x300" -10C bin 1x1
Astronomik G 1.25" Type IIc: 18x300" -10C bin 1x1
Astronomik Ha 12nm 1.25": 19x600" -10C bin 1x1
Astronomik L 1.25" Type IIc: 29x600" -10C bin 1x1
Astronomik R 1.25" Type IIc: 18x300" -10C bin 1x1

Integration: 12.7 hours

Darks: ~30

Flats: ~30

Bias: ~100

Avg. Moon age: 12.79 days

Avg. Moon phase: 84.39%

Basic astrometry details

Astrometry.net job: 2765550

RA center: 9h 55' 30"

DEC center: +69° 3' 50"

Pixel scale: 0.508 arcsec/pixel

Orientation: 179.168 degrees

Field radius: 0.289 degrees

Resolution: 3289x2434

Locations: Lighthouse Observatory, Burleson, Texas, United States

Data source: Backyard


Messier 81 (also NGC 3031 or Bode's Galaxy) is a spiral galaxy about 12 million light-years away, in the constellation Ursa Major. The galaxy's diameter of 90,000 light years is about half the size of the Milky Way. Due to its proximity to Earth, large size, and active galactic nucleus (including a 70 million sun supermassive black hole), Messier 81 has been studied extensively by professional astronomers.

Messier 81 was first discovered by Johann Elert Bode on December 31, 1774, and is sometimes referred to as "Bode's Galaxy". In 1779, Pierre Méchain and Charles Messier reidentified Bode's object, and listed it in the Messier Catalogue. Messier 81 is located approximately 10° northwest of Alpha Ursae Majoris along with several other galaxies in the Messier 81 Group.

Messier 81 and Messier 82 (not shown) can both be viewed easily using binoculars and small telescopes. Telescopes with apertures of 8 inches (20 cm) or larger are needed to distinguish structures in the galaxy. Its far northern declination makes it generally visible for observers in the northern hemisphere.

Most of the emission at infrared wavelengths originates from interstellar dust. This interstellar dust is found primarily within the galaxy's spiral arms, and it has been shown to be associated with star formation regions. The general explanation is that the hot, short-lived blue stars that are found within star formation regions are very effective at heating the dust and thus enhancing the infrared dust emission from these regions.

Only one supernova has been detected in Messier 81. The supernova, named SN 1993J, was discovered on 28 March 1993 by F. García in Spain. At the time, it was the second brightest supernova observed in the 20th century.

Messier 81 is the largest galaxy in a group of 34 galaxies located in the constellation Ursa Major. Fairly near to Earth, it makes this group and the Local Group, containing the Milky Way, relative neighbors in the Virgo Supercluster. [Source: Wikipedia]

CAPTURE Information:
The image was captured with the iOptron CEM120 mount , the venerable Meade 12"LX200 SCT, and my Atik 383L+ m CCD at F7.16 (2182mm FL). Image subs were taken through Astronomik's broadband filters Lum (L), along with R, G and B. Subs were done at 1x1 bin, -10C, at 10 minutes for Luminance; and 5 minutes for R, G and B.

IMAGE information -- 2019:
Ha: 19 subs (3.17hr) on May 13th and 14th.
Lum: 29 subs (4.83hr) on May 14th and 16th and Jun 14th, 17th, 20th and 21st.
Red: 18 subs (1.50hr) on May 16th and Jun 12th.
Green: 18 subs (1.50hr) on Jun 12th and 13th.
Blue: 20 subs (1.67hr) on May 16th.

Processing was done with PixInsight, following (for the most part) kayronjm's tutorial of Feb. 24th, 2013. I used the recently created Luminance Twilight Flats which have mostly corrected background problems. North is up and this is a slight crop due to the misalignment accumulation from the different filters and times.

I used the technique presented on Harry's Astroshed site for adding the Halpha images to the red images. You can see in the finished product where the isolated Hydrogen Alpha features are prominent in red.
The horizontal striations (lines) towards the lower part of the galaxy center are real. It is believed they resulted from gravitational effects from M82.



License: None (All rights reserved)

Sky plot

Sky plot


M81 Bode's Galaxy,