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September 2015 Urban Observing September 1, 2015

Posted by aquillam in Astronomy, Urban Observing.
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Special events

Star party

If you happen to be in southeast Michigan on September 25 or 26, head to Kensington Metropark! Kensington Astronomy at the Beach is the biggest astronomy event in the area, and a very unique one. Amateurs and professionals alike work together to put on this event that includes everything from guided sky tours to big ‘scopes you can look through. Talks, planetarium shows, demonstrations and activities go on no matter what the weather is like. Visit GLAAC.org for more information.

Meteor showers

September marks another lull in significant meteor shower activity. However, minor showers and the ambient meteor level are slightly higher at this time of year, so if you happen to be out late, or early, it’s worth watching for a few. As usual, it is much better to look for meteors under dark skies than the normal urban skies. Check out the weekly update form the american meteor society for week-by-week predictions.

Equinox

The autumnal equinox occurs on September 23 at 8:22 UTC , which is 4:22 AM in Michigan.

Lunar eclipse

A well timed total lunar eclipse occurs on September 27, starting just after sunset in Michigan. Maximum eclipse occurs in Ann Arbor and 10:47 PM, when the Moon will be high in the southeast. For timing details and more information, or information on another location, see http://www.timeanddate.com/eclipse/in/usa/ann-arbor.

Of course if there’s a lunar eclipse there must be a solar eclipse too. In this case, it’s a partial eclipse visible from parts of Africa and the Indian Ocean.

Moon:

Full: September 27. This is the closest full moon if the year.
New: September 11
Observers in the northeast may have the chance to see the Moon occult Aldebaran on September 5th. Unfortunately in southeast Michigan, it ends just before moonrise.

Planets:

Mercury is at greatest eastern elongation on the 4th, so it’s visible in the evening at the start of the month, but look for it soon. The ecliptic is low to the horizon at sunset for northern hemisphere observers at this time of year, so it gets really hard really fast to spot. On the other hand,southern hemisphere observers get their best chance all year! It’ll be in conjunction on the 30th, so no one will really get to see it by the last week of the month.

Looking west at 8 PM on 9/4

Looking west at 8 PM on 9/4

Venus is the gem of the morning skies. Just passed conjunction at the start of the month, it’s so bright it’s easily mistaken for plane or other terrestrial object. A pair of binoculars should be all you need to pick out it’s crescent shape. It’s headed for maximum westward elongation at the end of October so you’ll have plenty of time to spot it. It lines up with the Moon and Mars between Regulus and Procyon on September 9. Use binoculars or a small ‘scope to pull the objects out of the morning twilight.

Looking east before dawn on Sept 9.

Looking east before dawn on Sept 9.

In a mythically appropriate pairing, Mars is near Venus all month. Unfortunately it’s not nearly as bright as Venus so it’ll be tough to spot in the morning twilight. Also look for Mars and Regulus to make a close pair on September 25.

Looking east before dawn on 9/25

Looking east before dawn on 9/25

Jupiter is just past conjunction at the start of the month. Look for it in the morning twilight after the first week.

Saturn is well up at sunset now, the only naked eye planet in the evening skies. The ring tilt is big enough to be visible with just a pair of binoculars. A small ‘scope should enable you to pull out the Cassini division. It makes a nice pair with red Antares all month, but be sure to look on the 18th & 19th when the moon joins the pair.

Saturn, the Moon, and Antares on 9/18

Saturn, the Moon, and Antares on 9/18

Rising around 9:30 at the start of the month, Uranus is not a bad target no matter what time of night you observe. It pairs with the moon on the 1st and again on the 28th.

The Moon passes within a degree of Uranus on 9/28

The Moon passes within a degree of Uranus on 9/28

Neptune opposition is September 1, which actually makes this the best month this year to spot this distant blue planet. It’s a bit tough though. There aren’t many landmarks to guide you. The Moon will help on September 25.

The Moon can help you find Neptune on 9/25.

The Moon can help you find Neptune on 9/25.

Spitzer 12 month calendar for the 12th anniversary  August 21, 2015

Posted by aquillam in Astronomy.
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This beautiful, printable, calendar celebrates 12 years of infrared astronomy by the overachieving Spitzer space telescope.

http://ift.tt/1U219jU

Also, ifttt’s Do note is handy, Though it creates terrible titles for blog posts.

Celebrating a year at the comet / Rosetta / Space Science / Our Activities / ESA August 6, 2015

Posted by aquillam in Astronomy, MichiganAstro.
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Celebrating a year at the comet / Rosetta / Space Science / Our Activities / ESA.

Can you believe it’s been a year since Rosetta arrived at Comet 67P/Churyumov–Gerasimenko?? Such fantastic images, and the comet is nearing perihelion now, so there’s so much going on!

Guess I’d better put “update the comet lab” on my to-do list again!

August meteor showers  August 4, 2015

Posted by aquillam in Astronomy, MichiganAstro, Urban Observing.
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Although there are months with more meteor showers, and more productive meteor showers, August is known as the meteor shower month. That’s probably because being outside at 2 or 3 am in August depends mostly on whether or not you’re the kind of person who’s up at 2 or 3 AM, whereas being outside at 2 or 3 AM in November depends more on whether or not you have insomnia or have lost touch with reality. Even if you are the sort of person who is normally up at 2 or 3 AM, it’s a lot easier to convince yourself to go outside when it’s 60° than when it’s 6°. So let’s take a look at the August meteor showers.

First things first: what makes it a meteor shower? On a typical, average, non-meteor shower night, under dark skies you should expect to see six or seven meteors per hour. They’ll be spread randomly around the sky though, so it’s unusual for a single observer to see them all. Meteor showers occur when the meteors seem to come from a particular area of the sky, called the radiant. It usually also means more meteors, but the radiant is the important part. You’ll  generally see more meteors in the predawn sky since that’s when the sky overhead is facing the direction or his traveling. Think of it like when you’re driving in the car: more bugs hit the windshield then the side or back of the car.

The top diagram shows the time of day on Earth. The second diagram shows the direction Earth is traveling in its orbit. If you put those two together, you get the bottom diagram, showing that the part of Earth where it is both dark AND running into the meteors.

The top diagram shows the time of day on Earth. The second diagram shows the direction Earth is traveling in its orbit. If you put those two together, you get the bottom diagram, showing that the part of Earth where it is both dark AND running into the meteors.

The Perseids are of course the best-known meteor shower, and with good reason. With maximum rates reaching close to 100 in good years, it’s a reasonably active shower. Many of the meteors are also bright, so you can expect to see 10 or so even under moderately light polluted skies. They tend to be quick though, and don’t have persistent trains (they won’t leave a streak on the sky for a long time.) The number of meteors gradually builds from about mid July until the peak around the 12th or 13th, then drops dramatically right after the peak.  The show runs about two more weeks, gradually tapering off by about the 26th or 27th.

The 2015 peak should occur on August 13. The American meteor society (AMS) predicts a rate of about 50 to 75 meteors per hour. The radiant is actually circumpolar for most of the US & Canada, so anytime after midnight is worth going out, but it’ll be best around 3 – 5 AM, when the radiant is high in the northeast, and twilight hasn’t begun. Check the chart at the end for it’s location at 4 AM.

The Perseids aren’t the only show this month.

The Alpha Capricornids are a low rate shower, just around 5 an hour. However, it’s tendency to produce fireballs makes it worth watching for patient people. It peaked around July 29, but the difference between the peak and not peak is nearly insignificant. If you’re already out hunting early Perseids, you might as well find a spot where you can also see the southwest!

The Delta Aquariids  also peaked around July 29, but you’ll continue to see several of these every night until late August. These are faint, though, so avoid the waning moon nights, and find someplace dark. The radiant is pretty far south too, so the farther south you are, the better.

There are also a few other recognized meteor showers, but they have very low numbers. If you happen to have a clear night when you’ll be at a dark site, you should check out the weekly meteor outlook at the AMS. Also, if you happen to spot a fireball, you can help identify and track it by reporting it!

meteorShower (pdf)      meteorShower

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