Jupiter Opposition |2021

The best time to image and observe Jupiter (and Saturn or any other outer planet) is during opposition, when the planet, as viewed from Earth, is opposite the Sun (as the Sun sets in the west, the planet rises in the east), hence, the term opposition. Two conditions favorable to imaging happen during opposition: (1) Jupiter and Earth will be at their closest point in their orbits around the Sun, thus, making the planet appear largest when observed from Earth, and (2) Since the Sun is opposite Jupiter as viewed from the Earth, the planet is well-illuminated, thus, faster exposures can be taken resulting to sharper images. The Jupiter photo below was taken on August 7, two weeks before the 2021 opposition.

Jupiter imaged during the August 2021 opposition with a 4 inch f/9 refractor, 4x Barlow, and an ASI 533 camera. One of its large moon, Io, the cloud bands, and the Great Red Spot, are visible in this photo. Image processing done in SIRIL.

August is particularly rainy (and stormy) in the Philippines, and we seldom get treated with clear skies at this month.

For a complete list of astrophoto images, click here.

Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

Saturn | Eyepiece Projection

In eyepiece projection, an image is projected onto the camera’s sensor using an eyepiece. In this Saturn photo, I used a 4 in f/9 refractor and a 25 mm eyepiece to project an image onto the sensor of ASI 533 astronomy camera. The magnification of the image depends on the focal length of the telescope, the focal length of the eyepiece, and separation between the eyepiece and the camera’s sensor. While longer telescopes, higher-power eyepieces, and wider separation between the eyepiece and the camera will produce more magnified images, the amount of detail that can be resolved will still depend on the aperture or the diameter of the telescope’s objective mirror or lens.

Saturn imaged through eyepiece projection during the August 2021 opposition with a 4 inch f/9 refractor, a 25 mm eyepiece, and an ASI 533 camera. Image processing done in SIRIL.

For a complete list of astrophoto images, click here.

Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines