Observation Data
Location: Atlanta, GA (33.7384° N, 84.4234° W)
Date and Time: 2023-09-18, 22:20 – 22:57 EDT
Sky conditions: Seeing – Good, Transparency – Mag 3
Instrument: Celestron C8 SCT @f/20, Aperture 203.3mm, Focal length: 2023
Mount: Advanced VX
Eyepiece: N/A (Imaging)
Reticle Device: N/A
Imaging Equipment: ZWO ASI 120MM-S, 2x Barlow, ZWO filter wheel, Astronomik ProPlanet 642 BP IR-pass filter
Image type and sensor: CMOS, AR0130CS 1/3″ sensor
Image capture details: IR: Start capture: 22:49, End capture: 22:51, Exposure: 83.624ms, Gain: 70, best 20% stacked of 1436 frames. Software: ASICap, ASIVideoStack, Photoshop
Project Objectives
Within the three major rings that can be seen through the amateur telescope is the prominent gap known as the Cassini Division. It separates the “B” Ring, the brightest ring, from the “A” Ring and appears as a fine black line circling the planet. It is most easily seen on the two protrusions of the rings on either side of the planet known as ansae.
The axial tilt of Saturn and the inclination of Saturn’s orbit compared with the Earth’s, combine to cause the plane of Saturn’s rings to change their tilt. About every 7.25 years the rings go from edge-on to fully open. Your ability to see the Cassini Division will vary depending on how “open” or “edge-on” the rings are. Seeing and aperture size will also affect your ability.
Describe your view of the Cassini Division. Can you see it? Can you barely see it or does it “jump out at you”? How complete a circle of the rings can you detect? Include observation data and impressions.
Impressions
I have a decent view of the Cassini Division on the ansae. I can see that there is a darker division between the B and A rings, but it appears to gradually disappear. Saturn’s rings will be edge-on in March 2025, so the “gap” is closing, and we won’t be able to see the rings fully open until around 2031.