At Kenley Observatory in the last days of August, Kevin and I managed to capture a wide-angle portion of the Milky Way in Cygnus. Conditions identical to a month previous; same direction, same gibbous moon in the same place, 90 degrees away in the east. Also same equipment but exposing for 12 rather than 9 seconds, as the tracking is easily good enough.
Canon 70D dSLR, 20 Mpx cropped sensor, 24 to 70 lens set to 50mm, f/4, 50x12 secs at ISO 800 on fixed tripod.
An Omegon LX clockwork drive was used for tracking.
This time we set a longer remote timer delay of 30 seconds between exposures so the exposure time of 12 seconds (+12 s dark) was not truncated. Again used the noise reduction setting, which results in the camera exposing for a further 12 seconds after each shot with the shutter closed; these are the darks.
Polar alignment was by eye through a short plastic tube looking at Polaris, but drift over the 50 exposures was not much. Field of view would be close to 30° diagonal (26° by 17°).
Raw CR2 files processed in Deep Sky Stacker, this time set to best 100% so all 50 were used. Many satellite tracks were averaged out by DSS so not visible. No aircraft.
Tiff file processed in GIMP (histogram stretching, contrast, saturation). Image scaled to 4K, best viewed on a 4K TV or monitor.
Plate solved using
astrometry.net. This time the view is further to the north and a little east so the brightest star is Deneb, bottom right of centre.
An estimated 35,000+ stars in the field, but you need to zoom in on the original. The Milky Way runs from just below the top left corner to bottom centre.
A star of note:
- The well known 'The/Herschel's Garnet star', or Erakis, formally known as Mu Cephei, is to the top left, more or less diametrically opposite Deneb. By any standard a giant star, estimated larger then Betelgeuse, one of the largest and farthest stars seen by the naked eye.
https://www.star-facts.com/mu-cephei/ - There is another red star half way between Deneb and 51 Cyg, the reddest looking star in this photograph (you may need to zoom in to see it, but it's worth it), but only because at magnitude ~10.4 (var ±3.0) it is not overexposed like Mu Cephei. Known as: TYC 3578-2382-1, V Cyg, it is a carbon star. At about 1,200 light years it is half the distance of Herschel's Garnet star.
A crop of the region shows it to the top left.
An identical crop is from a single exposure - more noise, less stars.
Messier 39 is between 71 Cyg and 81 Cyg but to the right - Messier objects are not shown in astrometry plate solves. It really needs a higher magnification. Messier 29 is seen just below Sadr in the photograph from a month ago.
Fans of Messier 39 can order the T-shirt here...
https://www.redbubble.com/i/t-shirt/Messier-39-Open-Star-Cluster-in-Cygnus-by-galactichunter/28744864.1YYVUThanks for looking, William
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