Observation by Ian Sharp: M81 and M82 - 78.5 Hours Exposure

Uploaded by

Mr Ian David Sharp


Ian Sharp


2021 Apr 25 - 00:00


2021 Nov 10 - 12:14



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Ursa Major

Field centre

RA: 09h55m
Dec: +69°17'
Position angle: +88°38'

Field size

1°04' × 0°51'

  • StellaMira 104mm ED2 Triplet f/6.25 APO Refractor
  • Starlight XPress TRIUS PRO 694 mono CCD camera
  • 10Micron GM 1000 HPS mount
  • Starlight Xpress 7 position 1.25" filter wheel
  • Optolong LRGB, Ha, OIII, SII filters
  • Starlight XPress OAG
  • Starlight Xpress LoadStar V2 guide camera

Total of 78.5 hours


PixelSkies, Castilléjar in the province of Granada, Andalucia

Target name

M81 and M82


M81 and M82 - 78.5 Hours Exposure

About this image

Here is the deepest image I have ever processed, taken with my remote setup in Spain. Images were captured in April and May 2012.

Exposures : Red 112 x 300s, Green 112 x 300s, Blue 98 x 300s, Luminance 287 x 300s, HA 83 x 1200s

All calibrated with bias, dark and flat frames. All processing in PixInsight. Telescope control and image acquisition with Sequence Generator Pro. Guiding by PHD2 software.

More details are here: http://www.astro-sharp.com/2021/11/10/78-5-hours-exposure-on-m81-and-m82/

Pictures of the equipment are here: http://www.astro-sharp.com/2021/10/23/my-new-remote-setup-in-spain/

Files associated with this observation
Like this image
Grant Privett
Grant Privett, 2021 Nov 11 - 19:26 UTC

Serious question: has anyone on the BAA website had a longer exposure than this?

Mr Ian David Sharp
Mr Ian David Sharp, 2021 Nov 14 - 03:05 UTC

Interestingly, the number of exposures before rejection was about 98 hours!

Paul Leyland
Paul Leyland, 2021 Nov 29 - 17:12 UTC

Some of the GCs show up nicely as orange "stars".

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