British Astronomical Association
Supporting amateur astronomers since 1890

Secondary menu

Main menu

BAA Community Member Pages Dean Ashton
Image search

M81 and SAO 15017 & 15018


Expand image

About this observation
Dean Ashton
Time of observation
05/02/2018 - 19:45
Observing location
St Austell, Cornwall UK
235mm EdgeHD SCT
Off axis guiding using Loadstar X2 autoguider
Feather Touch focus control unit controlled with SGP.
Celestron Nightscape OSC CCD camera.
Celestron CGEM mount operated using NextRemote+ application; SkyX Pro; and SGP.
48x600seconds f/10
Like This Image

Eight hours of exposure were used to create this image of M81.  A real challenge was the fact that M81's angular dimensions are almost equal to the field of view of my OTA and CCD combination leaving no room to crop the images.  Fortunately the image just fitted.

To the lower left of M81 in this image are the 10th magnitude double stars SAO 15017 and SAO 15018.  The pair of stars are separated by an angular distance of 8.9 arcseconds.  The pair are around 250 light years away from the Sun.

Images were captured over three nights in January and February 2018, 11thJanuary, 4thFebruary and 5thFebruary.  The atmospheric conditions on all three imaging evenings were between 2-3 arc seconds of seeing.

M81 / NGC3031 is a grand design spiral nebula in the constellation Ursa Major, RA 09h 55m 33.2s; Dec. +69o03’55”.  The galaxy is relatively close to us at 11.8 million light years.  The galaxy has a linear diameter of about 90,000 light years and occupies an area of sky 27x14 arc minutes.  The Galaxy contains around 250 billion stars.

Copyright of all images and other observations submitted to the BAA remains with the owner of the work. Reproduction of the work by third-parties is expressly forbidden without the consent of the copyright holder. For more information, please contact the webmaster.