Jared May: What's up January 5 - January 11
The forecast looks cloudy this week, unfortunately. It’s the third week in a row of disappointing weather forecasts for stargazers and amateur astronomers. Sunset will be occurring around 5:20 PM, which is still very early and great to see the stars if you have an early bed time. The nighttime temperatures are pretty typical for this time of year, freezing or below. This week brings us the third quarter moon, Mercury near Jupiter and Saturn, and, since it will likely be cloudy, a section on astrophotography for beginners in this post to help prepare before before the next clear night.
Early morning Wednesday will be the official third quarter moon. This half-moon will begin to rise in the East around midnight which gives plenty of time to observe subtle night-sky objects without the moon’s blinding glow. As the moon approaches its new moon phase, it will rise later and later in the night and become a progressively narrower crescent.
On January 9th and 10th look low into the WSW horizon 20 minutes after sunset with a pair of binoculars to revel in the planetary trio: Jupiter, Saturn, and Mercury. They will appear to make a triangle in the sky. We can gather some information about the positions of the planets based on this observation.
Jupiter, Saturn and Mercury: this week in heavy twilight.
Since Mercury is an inner planet (closer to the sun than the Earth) and both Jupiter and Saturn are outer planets (further from the sun than the Earth), we can conclude that Jupiter and Saturn are nearly opposite of the Earth in their orbits (see the diagram below).
As we look out at Mercury, Jupiter and Saturn this week we are seeing them on the other side of the sun.
Some of the objects or astro-events that are discussed in these blogs are very difficult to see without the aid of a telescope or binoculars. Taking a picture through a telescope will not only “preserve” the astro-event or object in the image, but it enables us to see more than what the human eye can.
Many astrophotographers (including myself) get started in the hobby by taking quick snapshots through telescope or binocular eyepieces with their smartphone. With some practice, software, and a little time, you can take amazing astro-images.
To go beyond that, all you’ll need to get started is a DSLR, a lens with a moderately long focal length, and a tripod. You will also need to download the free software, “DeepSkyStacker”. A great beginner deep-sky object is the Orion Nebula found near the knee in the Orion Constellation. Frame up your shot using the longest focal length you have (<1000 mm). Make sure your camera is on manual focus, vibration reduction is off, the camera is in manual mode, and you are shooting in RAW (not JPG). Set up your camera’s onboard timer to shoot as many photos as you can manage, or be prepared to click the shutter button several times. Use the live view to manually focus stars. Start with an ISO of 800 or 1600 and use the “500 rule” to choose your exposure length (500/focal length = exposure time). Take lots of images (anything between 20 and 200 to start) while disturbing your camera as little as possible, this will eventually help increase the signal-to-noise, which is a top priority for astrophotographers.
After imaging, upload your RAW files to DeepSkyStacker and let it work its magic (there are lots of tutorials online for how to use this software on more advanced levels). This software aligns all of your images and averages them to increase the signal (the Orion Nebula) and decrease the noise (thermal noise, walking noise, etc.). You can make basic edits to your image in DeepSkyStacker or edit them in a photo editor of your choice. These are the basic steps to astrophotography and revealing otherwise invisible features of the night sky.
A simple DSLR setup, with a camera on a tripod, for taking simple “deep sky” images.
One of Jared’s images of the “belt” (at left) and “sword” of Orion, taken with a simple DSLR on a tripod. It is made up of dozens of images “stacked” in an image processing software, such as Photoshop.
If we are fortunate enough to find some gaps in the clouds this week, be sure to take a break and observe the cosmos. It is a humbling experience to lay eyes on a sea of stars knowing how distant they all are and realizing how small we are in the universe. Be sure to lookout for the third quarter moon, the planetary trio shortly after sunset, and perhaps prepare to do some astrophotography on Ohio’s next cloudless night this week. Clear Skies!