Cassiopeia Observatory logo

D850 DSLR Astrophotography Whirlpool Galaxy;
Another Visitor

Posted: 15 May 2018

Monday, 14 May 2018, dawned mostly clear with a clear sky forecast for the night. Wind returned mid-day.

Open: Monday, 14 May 2018, 1908 MST
Temperature: 77°F
Session: 1230
Conditions: Clear, breezy

Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece

iPhone 8 Plus

1915 MST: Venus visible high in the western sky.

1918 MST: sunset.

1919 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed Venus, 102X.

I then prepared the Nikon D850 DSLR for prime focus imaging.

1940 MST: SYNCed the AutoStar on the star Arcturus.

1950 MST: slewed to M51 (Whirlpool Galaxy). It was not yet visible against the bright twilight sky. Astronomical Twilight would not end until 2049 MST.

2003 MST: M51 faintly visible, 102X. 2028 MST: M51 spiral structure was visible. The breezes had calmed down now. 2035 MST: M51 spiral arms easily seen, 102X.

2039 MST: mounted the D850 DSLR at prime focus and focused on the star Arcturus using a Bahtinov Mask. Slewed back to M51.

2045 MST: StarLock ON.

Took these StarLock autoguided 1 minute and 5 minutes exposures, ISO 5000, White Balance 4000K:


Even the 1 minute exposure captured lots of details.

2102 MST: StarLock OFF.

Slewed to the star Spica and SYNCed the AutoStar. Then slewed to the galaxy Centaurus A, low in the southern sky. I was not going to image the galaxy this session as I needed to cut the session short due to a long day of activities planned for Tuesday, but I wanted to check its location above the horizon. I plan to image it on the next session.

Removed the camera. Viewed Centaurus A (galaxy), 102X.

Then viewed Jupiter and the four Galilean Moons, 102X.

2118 MST: LX600 OFF.

As I was closing up I noticed that there was this visitor over my head on the observatory dome:


He was about the size of a half-dollar coin.

Close: Monday, 14 May 2018, 2131 MST
Temperature: 69°F
Session Length: 2h 23m
Conditions: Clear

Comments are welcome using Email. Twitter users can use the button below to tweet this report to their followers. Thanks.

Previous report

Cassiopeia Observatory Home Page

Back to Top

Copyright ©2018 Michael L. Weasner /