Jared May: What’s Up This First Week of May

What’s Up This First Week of May

We are deep into spring now – more rainy days, but more comfortable overall temperatures both day and night. This week will likely be pretty cloudy and rainy with the exception of Wednesday night. Sunset will be passing through 8:30 PM and with sunrise at roughly 6:30 AM there is ten hours of darkness for stargazing and astrophotography.

It is interesting to draw a contrast between the length of night now and what it is on the shortest day of the year, the winter solstice, where Ohio sees nearly 14 hours of darkness.

Within the gaps of the clouds, be on the lookout this week for Eta Aquarid meteors, an early-morning eclipse on Jupiter, the rising core of the Milky Way, and the Summer Triangle.

The Eta Aquarid meteor shower peaks before sunrise on May 5 yielding around 20-30 meteors per hour. The whole shower lasts about a week so if you miss the peak, just try the night or two or three after. Meteor showers are the result of tiny particles that are shed off by comets passing through the solar system that slam into the earth’s atmosphere at insane speeds. Fun fact, the Eta Aquarid meteors are from the dust shed by the famous Halley’s comet! This particular meteor shower is known for having some of the fastest meteors, hitting the earth at over 148,000mph! At these speeds, the tiny sand-sized particles heat the air up so much it strips electrons off of the atoms (the process of ionization) and leaves a faint glowing trail for a few seconds.

The place that the meteors in a shower seem to come from is called the ‘Radiant”. The Eta Aqarid radiant does not rise until well after midnight.

In the early hours of May 7th, grab some binoculars and peer low into the eastern horizon. The brightest object in that part of the sky is Jupiter. Through binoculars or a low power telescope you will see all four of the Galilean moons off to one side of the gas giant. If you have access to a higher power telescope, look carefully and you may see a tiny black dot appearing on Jupiter’s surface. This is actually an eclipse (or shadowing of the sun) caused by the moon Ganymede.

Occasionally, one of Jupiter’s four big moons will cast a shadow on the body of the planet.

Jared May’s own photo of the shadow of Io crossing the face of Jupiter.

If you are a night owl like me, stay up past 11:30 PM to start getting a good glimpse of the returning Milky Way core. I say “returning” like it went away – it is always there, but just hidden away behind the sun in the winter months. The core of our galaxy is home to a supermassive black hole named Sagittarius A*. The massive gravitational force and other galaxy evolutionary processes cluster lots of stars and other cosmic objects into the galactic spiral arms and even more densely in the galactic core region. In a dark location the core (and even brighter parts of the spiral arms) will look like faint clouds stretched across the sky. This is actually the light of millions of stars. If you use a sky almanac or a software like Stellarium, you can find hundreds of nebulae, double stars, and more centered around this core region.

The milky-way rising over the eastern horizon after midnight this month.

How the milky-way will look at JGAP at around 3:00 am. Photo Brad Hoehne

At midnight look near the E-NE horizon and spot the Summer Triangle. This is a simple constellation consisting of three stars: Altair, Deneb, and Vega. This constellation overlaps with a section of one of the Milky Way spiral arms as well as indicates the onset of summer. Deneb is actually part of another constellation. It is the tail on Cygnus the Swan. Near Deneb is the very large North America Nebula (NGC 7000). This is a great astrophotography target but it helps to have a camera that is more sensitive to hydrogen alpha light.

The so-called “Summer Triangle” which rises after midnight in the East. It will rise earlier and earlier as spring turns into summer.

Despite sunset getting later in the evening and more cloudy days ahead, the temperatures are getting more comfortable and there are plenty of interesting cosmic treasures to see in the night sky. If Wednesday or the weekend nights are clear be on the lookout for some meteors, an eclipse over Jupiter, the rising Milky Way core, and the Summer Triangle near the North America Nebula.

Clear Skies!