Open: Thursday, 20 March 2025, 1811 MST Temperature: 81°F

Session: 2082 Conditions: Mostly clear, breezy

Equipment:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 2X Powermate
1.25" 3X Telenegative
1.25" 26mm Occulting Bar eyepiece
Focal reducer
2" UHC filter

Camera:
D850 DSLR

1815 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed Sirius, 102X and 203X. Viewed Sirius using the 1.25" 26mm eyepiece with Occulting Bar + 2X Powermate, 188X. I would try to observe Sirius B (the "Pup Star") as the sky became darker. Sirius A is Magnitude –1.46 and Sirius B (the "Pup Star") is +8.4, a difference in brightness of 10,000 times. Currently, Sirius B is 11.2" separation from Sirius A at about 2 o'clock (in the mirror-reversed eyepiece).

1838 MST: Sunset. Calm now.

Swapped the 2X Powermate with a 3X Telenegative for a magnification of 281X. I then began observing Sirius every few minutes.

1848 MST: Had a visitor to the observatory.

Click to view video

Prepared the D850 DSLR for imaging later.

1938 MST: The Zodiacal Light was visible in the western sky.

1945 MST: Ended my attempt to view the "Pup Star". Did not see it this session. I viewed Rigel, 281X, Occulting Bar, to view its companion star, which has nearly the same separation as Sirius B. The companion star was easily seen.

Mounted the D850 DSLR at prime focus + focal reducer + UHC filter, focused on Sirius, locked the telescope mirror, and slewed to NGC2359 (Thor's Helmet).

1955 MST: StarLock ON.

I did two short framing test exposures. Then began doing StarLock autoguided, ISO 4000, exposures. Unfortunately, clouds that had been low in the western sky at sunset were now approaching the sky where Thor's Helmet is located. Autoguiding became erratic. I only managed to get one good 5 minutes exposure, seen below (cropped and rotated).

Will try again for multiple exposures on a future session.

2010 MST: StarLock OFF.

Viewed NGC2359, 102X. Thor's Helmet Nebula was faintly visible.

2017 MST: LX600 OFF.

Close: Thursday, 20 March 2025, 2026 MST Temperature: 56°F

Session Length: 2h 15m Conditions: Mostly clear

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I have posted my review of Final Cut Camera.

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