Jared May: What's Up, December 10 - 17, 2021
We are getting into the middle of December now, but the temperature is still fighting to stay above 32°. Winter is notorious for bringing lots of cloudy skies, but this week seems to be an exception to that. It looks like there might be a few clear nights in the middle of the week. During these clear nights, the temperature will be dropping into the low 30s and high 20s with windchill. So make sure to dress warmly for stargazing and astrophotographers bring your dew heaters. Sunset is hovering around 5 PM this week so be ready to stargaze by 6 PM.
Be on the lookout this week for the first-quarter moon, more of comet Leonard, meteors, the moon passing the Pleiades, and some deep-sky winter nebulae perfect for beginner astrophotographers.
This Friday, December 10, will be the first-quarter moon. Knowing what phase the moon will give you a decent idea of where the moon will be in the sky that night. For the first quarter, we can figure that the moon forms a right triangle with the earth and the sun. For stargazers, this means the moon will be at its highest point in the sky right at sunset (at roughly 90° from the sun). The waxing crescent and first-quarter phases are perfect for observing the moon – it has not gotten too bright that it is blinding to look at through binoculars or a telescope, and the surface is very contrasty since the sunlight is hitting the deep craters and mountains at a steeper angle than if the moon were near full.
The first quarter is often the best time to view the moon because the lunar terminator, the line between night and day where the shadows are most distinct, is right down the middle.
It’s also a good time to view the moon in the early evening, because it is at its highest point in the sky right at sunset.
Comet Leonard (C/2021 A1) is starting to make more news as it brightens. This week will be the best time to view this comet since it will not be getting any brighter or higher in the sky. It shines at magnitude 5, so a pair of binoculars or a telescope is best to get a good view. To find this bright ice ball, head outside roughly 90 minutes before sunrise and look about 10° above the eastern horizon (On Friday). It will likely appear to be no more than a diffuse star with a hint of green color to it.
Comet Leonard will look a lot like comet Atlas did in early 2020 in this image taken by Joe Renzetti. Be sure to catch it as soon as possible.
This week will be the peak of a famous meteor shower – the Geminids. The true peak is Tuesday, but the moon will be bright and wash out most of the meteors unfortunately. The Geminids is no stranger to producing up to 120 meteors per hour in dark-sky locations. If you can not manage to spot any fireballs this week, do not worry. This meteor shower lasts from mid-November to the end of December.
One of the best meteor showers of the year, the Geminids, peak on the morning of December 13.
On Thursday, December 16, the moon will be accompanying one of the most famous objects in the night sky – the Pleiades cluster. By this point the moon will be deep into its waxing gibbous phase, so don’t expect to see more than a few of the brightest stars in this cluster like Maia or Electra which both shine a bright magnitude 3.8 or so (even when using a telescope or binoculars). Give the moon a few days to clear this part of the skies and find this cluster again and see how many more stars you can make out this time.
Like last month’s eclipse night, the moon will again be in the same region of the sky as the Pleiades on the night of December 16.
Many people will be gifting or will be gifted new telescopes or maybe a new camera. And these are great gateways into the wonderful world of astrophotography. It can be an intimidating hobby but it is extremely rewarding and there is a fantastic community of astrophotographers. Once all your equipment is ready, the next logical question is “what should I image first?”. With so many fantastic images from Hubble and others of brilliant deep-sky nebulae and galaxies, it may be tempting to go for these objects, but many of these are difficult to image. Some of the best winter-sky objects to begin imaging include the Orion Nebula, Andromeda Galaxy, Pleiades Cluster, M37 (globular cluster), and if you are feeling ambitious, the Horsehead and Flame Nebulae. All these objects listed (with the exception of the Horsehead and Flame Nebula) can be spotted using binoculars and can be enjoyed without astrophotography equipment too.
Objects of the late fall and early winter to point new telescopes at. All but the Horsehead are easily seen with both the naked eye and small telescopes. The Horsehead will require extremely dark skies and, most likely, a nebula filter.
The daytime temperatures are struggling to stay above freezing, but once the sun has set the temperatures will drop 10° or more with windchill. Enjoy the upcoming clear nights as they are not commonplace during the winter months in Ohio. The colder temperatures will help stabilize the atmosphere leading to more clear viewing of celestial objects. Be on the lookout this week for the first-quarter moon, comet Leonard, Geminids meteors, the moon and Pleiades meeting up, and prepare yourself for some wonderful nights of astrophotography or enjoying deep-sky objects with binoculars.
Clear Skies!