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SpaceX Starlink Train,
Flame Nebula with SHO filters

Posted: 18 February 2020

Open: Monday, 17 February 2020, 1814 MST
Temperature: 76°F
Session: 1440
Conditions: Mostly clear

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
SHO filters


SYNCed the observatory clock to WWV time signals.

I planned to try to see and photograph the SpaceX Starlinks satellites that were launched from Florida earlier this day. They were predicted to be bright enough to see at 1910-1911 MST if a deep Twilight sky did not interfer. Astronomical Twilight would end at 1933 MST.

Set up the D850 DSLR with 50mm lens on a camera tripod on the observatory patio.


1829 MST: LX600 ON, StarLock OFF, High Precision OFF.

1833 MST: viewed crescent Mercury, very low in the western sky, 102X. Then viewed a near half-phase Venus, 102X.

Slewed the 12" telescope to NGC2024 (Flame Nebula). It would be my Deep Sky Object (DSO) imaging target for the night using the Optolong SHO filters.

1843 MST: dome OFF.

1900 MST: began waiting for the Starlink satellites pass to begin. I did some test exposures of the sky.

1911 MST: I finally saw the Starlink train. To the eye it appeared as a solid line of light. Began taking photos (f/2, ISO 1600, White Balance 5560K, FL 50mm).


8.8 seconds

7.7 seconds (cropped with pointers to leaders and trailers)

14 seconds

Other satellites are visible in the 2nd and 4th photos.

1928 MST: returned to the 12" telescope and began preparing for DSO imaging. Mounted the D850 DSLR at prime focus using the Starizona Filter Slider System. Focused on the star Rigel with the HA filter using the Meade Bahtinov Mask. Locked the 12" primary using the ScopeStuff mirror lock. Slewed to NGC2024.

1936 MST: StarLock ON.

Took a framing test exposure, StarLock autoguided, 1 minute, ISO 6400, WB5560K. This is how an image looks if you forget to remove the Mask.


I removed the Mask, adjusted the framing, and took this StarLock autoguided, 1 minute, ISO 6400, WB 5560K, image. Some shadowing from the Filter Slider is evident at the bottom of the image.


I then took StarLock autoguided images, ISO 6400, WB 5560K, through each of the filters: HA (3 minutes), OIII (5 minutes), SII (15 minutes). This is the resultant image as processed in Photoshop by merging each of the three images. (I still have much to learn about using the SHO filters for DSO astrophotography.)


2018 MST: StarLock OFF.

I ended the session a little early as I wanted to get some sleep before getting up early the next morning for the occultation of Mars.

2033 MST: LX600 OFF.

2036 MST: dome ON.

2044 MST: took SQM reading.

Close: Monday, 17 February 2020, 2049 MST
Temperature: 52°F
Session Length: 2h 35m
Conditions: Clear, SQM 21.0

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