By David Ward
There is not much time for stargazing in June because the days are so long, with the summer solstice arriving on June 21. If you can stay up late enough to see any stars, look for the Summer Triangle coming up in the east just after it gets dark.
Three bright stars outline this large triangle and it is a great start to getting oriented in the summer night sky. The Summer Triangle is not a constellation, but an asterism, a pattern of stars. Each of its three stars is in a separate constellation.
The bright star Vega, fifth-brightest in the entire sky, marks the top of the triangle. The not-so-bright Altair is down and to the south, and Deneb is down and to the north. Due to a slow wobble that the earth makes known as precession, Vega will become our North Star in the future. Being much brighter than our current North Star, Polaris, it will be much easier to figure out which way is north.
To the lower right of Vega, look for Altair shining at another point on the triangle. The name of this star means “eye of the eagle” and it is the brightest star in the constellation Aquilla the eagle, which carried the deadly thunderbolts of Zeus, king of the gods in Greek mythology.
Both Vega and Altair are fairly close to us in space — not next-door neighbors, but just down the block, you might say cosmically speaking. The third star of the triangle, Deneb, to the lower left of Vega, is much more distant. No one knows for sure exactly how far away it is, but it is probably 100 times more distant than Vega and Altair. That means it must be really bright for us to be able to see it from so far away.
Deneb is the most luminous star we can easily see in the sky, shining as much as 200,000 times brighter than our sun. It is so large that it would engulf Earth’s orbit if our sun were at its center.
Do you ever wonder where you are going in life? If so take a look at the Summer Triangle. Our sun is headed through space in that general direction, more specifically towards Vega, a point known as the solar apex. In the future, Vega will become brighter and brighter and one day will outshine all the other stars in the sky. Unfortunately none of us will live long enough to witness this event.
Lots of excitement
Exciting things are happening with the planets this month. Watch Jupiter slide westward towards Venus getting really close by month’s end. On June 30 and July 1 during the evening twilight, we will be treated to a spectacular conjunction of the two brightest planets in the west. Conjunctions of Venus and Jupiter are not rare, but this will be a particularly close one. The pair will both fit together in the field of view of a telescope. Be sure to check out this celestial event, it will be spectacular and you do not have to have a telescope to enjoy it.
Look in the southeast for Saturn, the planet famous for its beautiful rings. Did you know that those rings are so thin that if they were scaled down to be as thick as a sheet of newspaper, they would be over a mile across? This year they are opened towards us almost as much as they get, a great time to look at them through a telescope.
Below and to the left of Saturn, the star Antares, the heart of Scorpius the scorpion, shines with a reddish hue. If you thought Deneb sounded big, Antares is far larger and probably about the biggest star we can see with the naked eye from Earth.
There is a lot of space between us and Deneb, about 12,000,000,000,000,000 miles of it. We often think of it as empty space, but how empty is it really? Astronomers tell us that about one atom floats around in every sugar-cube-size chunk of space between the stars. Surprisingly that is not enough material to dim our view of Deneb very much. Those lonely little atoms are not the only thing floating around out there. There is also a mysterious aspect of space called “vacuum energy” which may be the biggest component of the universe. Ideas vary widely about how much of this little-understood energy space holds. By some estimates that empty peanut butter jar you tossed into the recycling bin could contain enough power to boil off the entire Pacific Ocean in one second. Now that is quite a source of green (?) energy if we could just figure out how to extract it.
If you are totally lost up in the sky and cannot find Saturn, look for it just under the moon on the nights of June 1 and June 28. If you are trying to figure out which way is north, you cannot use Vega just yet. You have to wait until the year 13737 before it becomes the North Star.
Come stargazing with me, weather permitting, on June 21 at Sun Mountain Lodge, beginning at 9:30 p.m. It’s free.