Open: Friday, 13 March 2026, 1823 MST Temperature: 89°F

Session: 2118 Conditions: Mostly clear

Equipment:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
1.25" 26mm occulting bar eyepiece
2" 4X Powermate

Camera:
iPhone 15 Pro Max

1831 MST: LX600 ON, StarLock OFF, High Precision OFF.

Slewed to Sirius. It was bright in the bright twilight sky, 102X. If the clouds permitted, I planned to try to observe Sirius B (the "Pup Star"). It has been several years since I've seen the Pup Star (Mag. +8.4). Sirius B is a companion star of Sirius A (Mag. -1.5) and is difficult to observe due to the bright glare from Sirius A. I would use my Occulting Bar Eyepiece to block out Sirius A for the observation.

1834 MST: Sunset.

1837 MST: Relaxed on the observatory patio bench outside of Cassiopeia Observatory.

1856 MST: An airliner passed close to Jupiter. iPhone 15 Pro Max photo, Camera app (Night Mode, 3 seconds, 1X lens, cropped).

1900 MST: Dome OFF.

1907 MST: Back in the observatory I observed the Pup Star, 375X. The high magnification (26mm eyepiece + 4X Powermate) and the occulting bar really helped. I slewed the view around to confirm that what I saw was in fact a star and not an artifact from the glare from Sirius A.

1913 MST: Clouds were increasing, as seen in this iPhone photo (Night Mode, 3 seconds, 1X lens) showing the planet Venus low in the western sky.

Mouseover or tap on image for label

I attached my LiDAR Cover on the iPhone and mounted the iPhone on the 26mm eyepiece using the Accuview 3-Axis Smartphone Adapter. I was able to image Sirius B (Pup Star), afocal 375X, using the NightCap Camera app (Long Exposure, 6 seconds, ISO 6400, 1X lens).

Compare the mirror reversed image above with this chart of the orbit of Sirius B.

Chart FrancescoA/Wikimedia Commons

1935 MST: The clouds had reached the Zenith.

Viewed Jupiter and the four Galilean Moons, 102X.

1939 MST: Returned to the bench to monitor the clouds.

1941 MST: This iPhone photo (Night Mode, 3 seconds, 1X lens) shows some of the clouds. Canis Major is at the lower left, Orion in the center, the Hyades in Taurus and the Pleiades at the upper right.

1947 MST: Decided to end this session.

1951 MST: LX600 OFF.

1955 MST: Dome ON.

Close: Friday, 13 March 2026, 1958 MST Temperature: 67°F

Session Length: 1h 35m Conditions: Partly cloudy

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