Cookie consent

AstroBin saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing AstroBin without changing the browser settings, you grant us permission to store that information on your device.

I agree
Contains:  Extremely wide field
Getting plate-solving status, please wait...

The Wandering of Saturn

Technical card

Dates:July 7, 2018July 8, 2018July 13, 2018July 14, 2018July 30, 2018Aug. 11, 2018Sept. 7, 2018Sept. 8, 2018

Frames: 34x120" ISO800

Integration: 1.1 hours

Avg. Moon age: 15.26 days

Avg. Moon phase: 21.47%

Basic astrometry details job: 2494829

RA center: 18h 10' 14"

DEC center: -23° 6' 43"

Pixel scale: 8.439 arcsec/pixel

Orientation: 0.707 degrees

Field radius: 5.071 degrees

Resolution: 3600x2400

Data source: Traveller



"There was another kind of object in the sky, the wandering or vagabond stars called planets. Our nomadic ancestors must have felt an affinity for the planets. [...] They moved against the background of more distant stars. If you followed their apparent motion over many months, they would leave one constellation, enter another, occasionally even do a kind of slow loop-the-loop in the sky." [1]

In Cosmos, Carl Sagan puts it beautifully: planets are wanderers of the stars. The term planet's origin ties to history, astrology, science, mythology, and religion. The naked eye planets were regarded by many early cultures as divine, or as emissaries of deities. If you look up at night, there are great chances the brightest bodies you will see will be the planets. To the naked eye, they look just like bright stars. Early astronomers noted that some "stars" were not fixed - they moved across the sky. Greeks called them πλανῆται (planētai, or "wanderers") [2]. Explaining and precisely predicting this motion was a task for many astronomers and astrologers in Ancient times.

This wide field potrays part of 2018's motion of Saturn, in a beautiful Milky Way field. Saturn crossed the region in Sagittarius where great deep sky object lies: Lagoon Nebula, M8, and Trifid Nebula, M20 are the most prominent objects in the region, catalogued by Charles Messier in 18th Century. Some othre interesting objects lie in our Milky Way's plane: dark nebulas, the globular clusters M28 and NGC6544, in a dense starfield.

This image was captured in multiple sessions throughout 2018's Winter. The images from 7, 8 and 30/july; and 11/08 and 07/09 were caputred from my dark sky site in MG. The 13/07 and 14/07 images were captured during the 11º Encontro Brasileiro de Astrofotografia (Brazilian Astrophotography Meeting), in GO, some 1200km away. I find it interesting that the slightly different atmosphere conditions created some color variation in Saturn for each date.

Processing the data was not trivial. First all the images were combined used pixel rejection. That way, Saturn was considered an outlier, and got removed. This is the base background, with deeper integration. The individual sets from each night were then integrated separately. Each set consists of 1, 2, 4, 5, or 16 light frames of 120s, depending on the day. Each were calibrated with the respective calibration frames. Once registered, each "Saturn" frane was blended to the base image, which was then post-processed as usual. This way, the planet motion could be traced out. The labelling and the motion line (based on Stellarium software) were finally added.

Date and Time: July 7, 8, 13, 14 and 30, August 11, September 7, 2018.
Location: MG and GO, Brazil. Rural Skies (Bortle 2.5-3.5, SQM ~21.6*calculated)
Camera: Canon EOS T5/1200D (modded), at ISO 800
Lens: Samyang 135mm f/2, operated at f/2.4
Mount: Sky-Watcher HEQ5, tracking, guided
Guiding: Starguider 50mm Guidescope + ASI120mm + PHD2
Exposure Detail: 34x120s total 68 min

[1] Cosmos, The Harmony of the Worlds, p. 45, Carl Sagan, 1980 [2] Wikipedia, "Planets".



Gabriel R. Santos...
License: None (All rights reserved)

Sky plot

Sky plot


The Wandering of Saturn, 


            Gabriel R. Santos...