Thursday, June 12, 2014

Jupiter Moons and Red Spot - Astrophotography - Celestron 4SE

How does Jupiter hold up his trousers?

With an asteroid belt.

--Astronomy Jokes

Jupiter is one of the most exciting objects to observe in the solar system. Even a small telescope reveals its bright cloud belts, the famous Great Red Spot, and the four large Galilean moons — Io, Europa, Ganymede, and Callisto. Watching these moons change position from night to night (and sometimes hour to hour) is one of the highlights of amateur astronomy.

This photo was taken with my Celestron NexStar 4SE Maksutov telescope from Brooklyn, NYC. For bright planets like Jupiter, Mars, Venus, or Saturn, light pollution is not a problem at all. These planets are extremely bright, and the telescope’s tiny field of view blocks almost all city glow. Light pollution mainly affects faint stars and the Milky Way, but not planets — they remain sharp and clear even in a heavily light-polluted city like New York.

Capturing both Jupiter’s atmospheric details and all four moons in a single frame is not easy. The planet needs a very short exposure to reveal the belts and the Great Red Spot, while the moons require a much brighter setting. For the final image, I combined two photos — one optimized for Jupiter itself and another for the moons. I checked the ephemeris for that night so I could label each moon correctly. The positions of Jupiter’s moons can be easily found using online tools — for example, the Sky & Telescope Jupiter’s Moons calculator.

The Image

Jupiter with the Great Red Spot and Galilean moons captured through a Celestron 4SE telescope from Brooklyn NYC – astrophotography image

Jupiter Moons and Red Spot Astrophotography Celestron 4SE - Brooklyn NYC

What You Can See in the Image

Jupiter’s two main cloud belts
The Great Red Spot on the disk
All four Galilean moons correctly positioned for that night
Labeled moons based on calculated ephemeris

For a compact 4-inch telescope, this is a very satisfying result. The combination of sharp planetary details and the full set of moons gives a realistic view of the dynamic Jupiter system.

Gear & Technique

Telescope: Celestron NexStar 4SE Maksutov
Mount: GoTo Alt-Az
Method: Two-photo composite — short exposure for Jupiter, brighter exposure for moons
Main challenge: Huge difference in brightness between planet and moons

This image shows what a small telescope can do even in the middle of a major city. Planets are bright enough to cut through light pollution, and their details are visible whenever the atmosphere is steady.