‘Summer constellations’ begin in June
May has been pretty wet and the nights available for observing the sky have been fewer than I had hoped. June should be drier and the beginning of the ‘summer constellations’ begins. The shortest night of the year will occur in the Northern Hemisphere on the night of June 21. This is the summer solstice.
On the first days of June, if you are up at dawn, look to the east-northeast before the Sun comes up and see Venus. Venus lies closer to the Sun than Earth does so from our perspective, Venus will never wander very far from the Sun in our sky. Because Venus is very bright, some amateurs have seen Venus in the daytime, but this is very difficult.
On June 4, the Moon will be one day past new in the west-northwest. The tiny planet Mercury will be 6 degrees to its right. It will look star-like. Mercury is even closer to the Sun than Venus [only about 13 million from the Sun] so it is always seen, morning or evening, not far from where the Sun is in the sky.
After June 10, Jupiter, the biggest gas giant planet in our solar system, will be up all night. Binoculars, held very steady, may reveal some of Jupiter’s moons— the same ones Galileo spotted early in the 1600s.
When the Moon is one day past full, you can find Saturn, 1 degree away from the Moon. Find Saturn and the Moon in the southeast. Saturn will be the brightest object that’s close to the Moon, it will not twinkle, as stars do, and it will be a sort of yellowish color.
Last month, I wrote about the Coma-Virgo cluster of galaxies and this cluster can still be seen in June, near the tail of Leo. The three galaxies I included in last month’s column were all spiral galaxies, as is our own Milky Way. Around the edges of many spiral galaxies, observers may often find globular clusters. Globular clusters are thought to have formed from residual matter around spiral galaxies that was just outside the gravitational attraction of the spiral itself. This residual matter attracted itself and formed spheres of stars that have anywhere from 50,000 to over 1 million stars within that sphere.
Our Milky Way has many globular clusters around it. Some might as yet be undiscovered because in the direction of the center of our galaxy, we can’t see so some may be hidden from our view. Astronomers can see many globular clusters around other spiral galaxies as well.
In June, there is a wonderful globular cluster, near our Milky Way, which can be seen with binoculars. It is called M13. At mid-month, it is nearly directly overhead in the constellation Hercules. If you want to find it, first use your computer and look up Hercules. The spot where you could find M13 should be marked on a map of this constellation. Or, just enter M13 in your computer and you may see a map where it can be found. [I should say that, out under the stars, M13 can be best seen lying on your back!] In binoculars, it will be a small circular patch of light, but you won’t be able to see any stars unless you use a telescope. I have included an image of M13 I made a few years back with an 8-inch telescope I owned. There are so many stars near the center that the center stars are over-exposed. I wanted to image as many of the ‘edge’ stars as I could and this resulted in the overexposure. You will find really spectacular images of M13, made by other amateurs, out on the Web.
Soon, our own Milky Way galaxy will be displayed across the night sky. It is a great treat to see it with binoculars. I will have more to say about this as summer comes on. Clear skies!
— Dr. David Cater is a former faculty member of JBU. Email him at starbug352@yahoo.com. The opinions expressed are those of the author.