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D850 DSLR: 40 Eridani,
Crab Nebula & Asteroid Nysa

Posted: 19 March 2022

Open: Friday, 18 March 2022, 1813 MST
Temperature: 82°F
Session: 1737
Conditions: Clear

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" UHC filter


SYNCed observatory clock to WWV time signals.

Prepared D850 DSLR for imaging. Did some back focus measurements to reach 110mm back focus with the DSLR. Removed the visual back extension to achieve this distance.

1837 MST: Sunset.

Relaxed on the observatory patio bench for a few minutes.

1852 MST: Back inside the observatory.

1853 MST: LX600 ON, StarLock OFF, High Precision OFF.

1856 MST: Dome OFF.

1857 MST: Wi-Fi ON.

Used SkySafari 7 Pro on the iPhone 13 Pro Max to GOTO 40 Eridani (also known as Omicron² Eridani). This is Mr. Spock's (Star Trek) home star with the planet Vulcan.

Mounted the D850 DSLR at Prime Focus photo , focused on Rigel, and locked the 12" mirror.

1903 MST: Wi-Fi OFF.

1912 MST: StarLock ON.

Took this cropped photo of 40 Eridani, StarLock autoguided, 2 seconds, ISO 3200, White Balance 4550K. The primary star, 40 Eridani A (Mag. +4.43, main sequence star), the secondary star, 40 Eridani B (Mag. +9.52, white dwarf star), and the tertiary star, 40 Eridani C (Mag. + 11.17, red dwarf star) are visible in the photo.


Added the 2" UHC filter, focused on Aldebaran, and locked the mirror.

1927 MST: The eastern sky was beginning to brighten from the rising just past Full Moon.

Slewed to the Crab Nebula (M1) to image Asteroid (44) Nysa passing in front of the nebula. Took StarLock autoguided, 5 minutes, ISO 3200, WB4550K, exposures at 193530 MST and 200530 MST. Here is a cropped image and animation showing the nebula and asteroid.


Thanks to Scott Kardel for the asteroid tip!

2009 MST: The Moon was rising over the hill to the east.

2011 MST: StarLock OFF.

2015 MST: Dome ON.

2020 MST: Took this prime focus + UHC filter image of the Moon, 1/250sec, ISO 500, WB4550K.


Viewed the Moon, 102X. A slight terminator was visible.

2028 MST: LX600 OFF.

Close: Friday, 18 March 2022, 2036 MST
Temperature: 54°F
Session Length: 2h 23m
Conditions: Clear

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