Sun rises at 5:40am.
Sun sets at 6:51pm.
Moon phase: New Moon
Moon rises at 3:56am
Moon sets at 5:11pm
At the heart of our galaxy
When you look up into our night sky, the direction towards the center of our galaxy is marked by the constellation Sagittarius. Although it is meant to represent a centaur, the brightest stars in this constellation looks a little like a teapot on its side. It hangs in our southern sky at this time of year and snuggles up against the Milky Way which is our view of our own galaxy.
A super-massive black hole sits at the center of our galaxy, it’s known as “Sagittarius A Star” and it weighs as much as four million of our suns. Astronomers determined that mass by measuring the orbital movement of nearby stars. As the stars get closer to the black hole, they speed up. The speed tells them there is a small highly concentrated bit of matter that tugs at the orbiting stars. No one has seen the black hole itself. Its event horizon, the point of no return for matter that falls into the black hole, is about 14 million miles across. That’s a big target, but from our distance away (27,000 light years) it’s still too small to measure with any existing telescope. Yet there is an effort underway to “see” the black hole nevertheless. Astronomers are linking radio dishes around the world in a project known as the Event Horizon Telescope. Combining several widely spaced telescopes produces images as sharp as those made by a single telescope as big as the earth!
The goal is to see the outline of the black hole. The black hole’s gravity should distort the view of the gas and stars behind it producing a glowing ring, a ring which outlines a black hole!
Planets among the stars
You can recognize the planets among all the stars by studying them night after night. The stars remain in the same locations relative to each other, as if they are fixed on the celestial dome slowing rotating above us. Planets look like bright stars, but they are in slightly different locations relative to the stars; over time they “wander” across the celestial dome. In fact, the word planet means wanderer. Also the planets will always be located somewhere along the ecliptic. That’s a fancy word that means the path which the sun and the moon follow from the eastern horizon to the western horizon.
Some stargazers are fond of saying that planets shine and stars twinkle, and that may help tell the difference if you are far from any atmospheric disturbances, clouds or city lights, but honestly, I have found that isn’t a very helpful rule of thumb. When in doubt, binoculars will generally show you a planet from a star. Be patient with your eyes and focus carefully, find ways to steady your hands, the mystery of the universe is out there for you to observe, but it takes a while to learn the tricks.
This weekend, look for Jupiter in the west just after sunset. It will set about 10:40pm. Meanwhile, Mars and Saturn are still chumming around together close to the bright star Antares. Last week, the writer of this column mistakenly said this triangular cluster was Mars, Saturn and Arcturus, that was in error, so please forgive! It’s Antares. Although Arcturus is not so far away, just to the west of the trio, in the constellation of Bootes.
Thank you for keeping up with the Night Sky articles. Comments and feedback are always welcome. If you are out later on in the week, each star rises about four minutes earlier each day than written here, and the moon rises 50 minutes later. Night Sky is researched and compiled by Lisa Davis-Burnett, email: This email address is being protected from spambots. You need JavaScript enabled to view it..
