Jared May: What's Up, January 18-25

We are only two weeks away from the halfway point of winter, and it certainly feels that way. Most of this week will be cold, cloudy, and may bring a little bit of snow. There is, however, a chance for clear nights closer to Thursday and the weekend. The nighttime temperature for some of these clear nights will be as low as 3° with wind chill.

If you are brave enough to go stargazing on a cold night like that, dress warmly to protect yourself from frostbite and limit your star-gazing sessions to a few minutes at a time.

Sunset this week is around 5:35 PM so most of the faintest night-sky objects will be visible just an hour later. This week be on the lookout for the full moon (and a few methods to combat the bright moon while stargazing), a big Big Dipper, Uranus overhead, and a faint ring around the Orion constellation.

Monday, January 17, is the full moon. You will notice that as the sun sets in the west, the eastern horizons become brighter as the moon rises. Unfortunately for us stargazers, a full moon means that much of the night sky is washed out from the blinding light reflected off the lunar surface. If you observe the full moon (or even the gibbous moon) with binoculars or a telescope it helps to have a moon filter. These are very cheap and reduce the brightness of the moon. Observing the full moon with binoculars or a telescope is a sure way to ruin your night vision. Do not worry though, it will return in several minutes.

The full moon may be lovely, but it makes viewing other celestial objects, especially galaxies and nebulae, difficult.

The best solution to stargazing under a full moon is simply to wait until it is no longer a full moon. If, however, you are desperate to do some stargazing, it may help to use binoculars and a telescope for celestial objects relatively far away from the moon’s glow. So anything low in the northern sky is perfect.

If you are an astrophotographer, fighting the moon’s glow becomes an interesting game. The best solution is to use narrowband filters. These are unfortunately expensive, but will block out light pollution, make your colors “pop”, and will even help block out some of the moon’s light.

When you look at things in the night sky, you generally see them in the sea of stars and far above the horizon. If you have ever seen the moon low to the horizon, it appears very large. This is because the horizon has objects like trees and houses whose sizes are familiar. By adding these frames of size reference, you can get a true sense of how large some stargazing targets are. A perfect example this time of year is the Big Dipper. Around 8:30 PM most of this constellation is above the northeastern horizon. Find the Big Dipper around this time and compare it with the trees and houses on the horizon and see how BIG it really is.

The “moon illusion” makes the Big Dipper appear even bigger than normal this month.

Any time this week, look direct above then 30° south and scan the skies with binoculars. If you come across a blue/green magnitude 5.8 star, then you have found Uranus. Even a more powerful telescope will struggle to resolve many details of this outer planet since it is so far away (roughly 20x the distance from the sun as the earth).

Uranus was the first planet to be discovered since antiquity. It can be seen with the naked eye, just barely, under superb conditions and dark skies. Generally it is easier to use binoculars or a small telescope.

If you are in a very dark location or enjoy astrophotography, then you should try hunting for a faint red region of nebulosity that surrounds much of the Orion constellation. This red ring is called Barnard’s Loop. This region of gas is ionized by the hot stars found inside of the Orion Nebula and is thought to have originated from a stellar explosion over 2 million years ago. (Image : https://apod.nasa.gov/apod/ap050420.html)

Barnard’s loop is, most likely, impossible to see with the unaided eye. However, photography can bring out its faint glow.

Prepare for the cold and step outside for a few moments on a clear night this week and enjoy the twinkling stars and winter constellations. The cold temperatures help stabilize the atmosphere and reduce turbulence so the stars may appear to twinkle a little less than in the summer. During the one or two clear nights this week try hunting for the full moon, observing constellations near the horizon, scanning for Uranus, and finding the faint Barnard’s Loop. Clear Skies!