Cassiopeia Observatory logo

Nearly Full Moon, Pup Star iPhone test;
Star Canopus

Posted: 10 February 2017

Sunday, 5 February 2017, began with a mostly clear sky, but it was overcast by early afternoon. Cloudy nights continued until Thursday, 9 February. The forecast was for a cloudy night but the sky began clearing after sunset.

Open: Thursday, 9 February 2017, 2002 MST
Temperature: 70°F
Session: 1071
Conditions: Mostly clear

Equipment Used:
12" f/8 LX600 w/StarLock
Wired AutoStar II handset
2" 24mm UWA eyepiece
2" 30mm eyepiece
2" 9mm 100° eyepiece

iPhone 6s Plus
D7200 DSLR

2007 MST: LX600 ON, StarLock OFF. High Precision OFF.

Viewed the Moon, 102X, less than a day before precisely Full. A slight terminator was visible. The Moon was very bright.

Then began setting up to photograph the Moon. Switched to a 2" 30mm eyepiece (81X) and mounted the iPhone using the Levenhuk Smartphone Adapter. Used the iOS app NightCap Pro for this image:


2021 MST: I wanted to try a test this night. Could I photograph the "Pup Star" (Sirius B) using the iPhone and NightCap Pro? First, I slewed the 12" telescope to the star Rigel and switched to a 2" 9mm 100° eyepiece (271X). Focused on the star using the Astrozap Bahtinov Mask. Rigel's companion star was easily seen. It is at a similar distance to that between Sirius A and Sirius B and so would be a good guide for the "Pup Star". Mounted the iPhone using the Levenhuk adapter and did a 15 second video recording using NightCap Pro (ISO 400, 1/60sec). I then slewed to Sirius, tweaked the focus using the Mask, and did a 15 second video recording using the same exposure settings. Here are single frames from the two videos, cropped:

photo photo

Rigel's companion is visible (below the main star), but the "Pup Star" (which would be to the right of Sirius A) was not captured. Will try again on a future session using a higher magnification to increase the separation of Sirius B from Sirius A.

2039 MST: ended the iPhone imaging tests. I then tried observing the "Pup Star", 271X, but without success. I had seen it with the 8" LX200-ACF telescope but have yet to observe it with the 12" telescope.

2047 MST: slewed the telescope to the star Canopus, which was very low in the southern sky. Canopus is the third brightest star in the sky after the Sun and Sirius. I used the D7200 DSLR for this photograph of Canopus just above the mountain to the south and the moonlit observatory, f/11, 10 seconds, ISO 1600:

Mouseover or tap on image
Mouseover or tap on image for a pointer to Canopus

2104 MST: LX600 OFF.

Close: Thursday, 9 February 2017, 2110 MST
Temperature: 65°F
Session Length: 1h 08m
Conditions: Mostly clear

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

Previous report

Cassiopeia Observatory Home Page

Back to Top

Copyright ©2017 Michael L. Weasner /