Jared May: What’s Up During the Last Week of August
The weather for this upcoming week is not looking too promising for stargazers. Ohio weather has, however, been known to have surprises. The sunset this week is around 8 PM meaning you don’t necessarily have to be a night owl to see some of what the sky has in store this week. The first stars and planets begin to pop out from the sky background around 30 minutes after sunset. The first noticeable objects include the moon, Jupiter, Saturn, the Summer Triangle stars, and Antares. In addition to these bright objects, this week also holds a unique time to view the first ever discovered asteroid (now dwarf planet), Ceres. This week is also a perfect time to use some binoculars or a telescope to observe the famous double star system of Albireo.
On Tuesday the moon will pass through its first quarter phase. This is where only half of the side facing us is illuminated by the sun. first/third quarter and the crescent phases are my personal favorite times to observe the lunar surface with binoculars or a telescope. During these phases there is lots of contrast on the surface and many craters can be seen right along the moon’s terminator (where the illuminated side meets the unilluminated side).
Jupiter and Saturn can both be seen relatively close to each other in the south/southeast skies just after sunset as two distinctly bright looking “stars”. A telescope with a moderately long focal length will be able to resolve the red and tan stripes found in Jupiter’s atmosphere. Point this telescope 8° further east to find Saturn and you will easily see the ovular appearance of the planet. This is due to the planet’s massive ring system that is about 240,000 miles wide! If seeing conditions are good and the telescope’s focus is sharp, the Cassini division can be seen in the rings. This is a small part of the rings that appear darker because most of the material for the rings in that orbit is actually missing. This “missing” material was just displaced by Saturn’s moon Mimas.
Saturn is one of the most engaging sights through small telescopes.
These next few objects are very close to the zenith (directly overhead). This puts them in a very good position for viewing, yet a very inconvenient position. The atmosphere distorts light that passes through it (example, stars twinkling) and the zenith is where there is the least atmosphere that star light must travel through to reach our eyes. It is inconvenient, however, because unless you are laying down or have a reclining chair you must crane your head back which may become uncomfortable after several minutes. The summer triangle is a constellation that now hangs directly overhead. It consists of three bright stars: Vega, Altair, and Deneb. Together they form a very easily seen triangle in the sky that stretches nearly 35° from the zenith. Right in the middle of the summer triangle is the famous double star, Albireo. It can be seen with most binoculars and telescopes. Albireo will stand out as it consists of two rather bright stars: a very red star and a very blue star (appears slightly smaller relative to the red star). This double star system is around 400 light-years away and the two stars orbit each other once every 214 years – a little too slow to notice over the course of a single night.
While you have your binoculars or telescope out, stay outside until about 10 PM when the dwarf planet Ceres rises above the horizon. It was the first asteroid ever discovered (before getting promoted to dwarf planet status in 2006), found in the year 1801 by Giuseppe Piazzi. Ceres reaches opposition on Thursday and shines a faint magnitude 9 low in the southeastern skies.
An illustration of Ceres based on imagery from NASA’s DAWN probe. The bright patch confounded astronomers for many months before it was discovered that the material were salts, deposited as salty water sublimated away into space, leaving dissolved minerals behind.
Many of these objects and events are not exclusive to this week, so it’s not a total loss if the weather doesn’t work out in our favor. Be on the lookout for those clear nights and grab a lawn chair, some binoculars or a telescope, some bug spray, bring a curious mind and get outside to relax and enjoy the cosmos.
Clear Skies!