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August 2015 Urban Observing August 1, 2015

Posted by aquillam in Astronomy.
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Special Events

Meteor Showers

August is known as the month of meteor showers. The Perseids and the best known and the best shower in August, and should peak on the 13th this year. That means you should observe sometime between midnight and 5 AM on the morning of the 13th and/or 14th. There are a few other meteor showers too, but they aren’t as big, so I think I’ll leave that for another post so I can get this one finished before the 1st!


Full Aug 29 18:38 UT (2:38 EDT).
The Moon is at perigee about 20 hours latter, at 15:22 UTC (11:22 EDT), making this a supermoon.
Being late summer, it’ll be higher in the sky than the last few full moons, so it’ll be even more problematic for deep sky observers. According to the Old Farmer’s Almanac, the August moon is the Sturgeon or Green Corn Moon.



Mercury peeks out of the evening twilight this month. on the fist it sets 35 minutes after the Sun so you’ll have to work to find it. By mid month it’ll hang out nearly an hour after the Sun sets. It reaches aphelion on August 29, and greatest eastern elongation on Sept. 3, so it really doesn’t get farther from the Sun than this! It’s still a tiny planet in twilight though, so binoculars or a small ’scope are very helpful. Look for a Jupiter-Mercury conjunction on August 6, and for Mercury with a young crescent Moon on the 16th.

The Moon and Mercury in the evening twilight

The Moon and Mercury on August 16 at dusk

Mercury and Jupiter in twilight

9 pm on August 6, 2015


Venus reaches Inferior conjunction on August 15, so it’s not visible most of the month. If you happen to be up before 6:30 though, start looking for it in the east beginning around August 21. It zips past Mars at the end of the month / early September.
Venus and Mars just before dawn on August 31

Venus and Mars just before dawn on August 31


Mars is for morning observers this month. A very old Moon will be near it on August 12, but it’ll be tough to spot without binoculars. It crosses M44 on Aug 19, but you’ll need a ‘scope to pull the cluster out of the twilight.

Mars and the Moon near Gemini

Mars and the Moon pair up in the pre-dawn sky on August 12


Jupiter disappears quickly into the twilight this month, reaching conjunction on August 26. Before it disappears, catch it pass half a degree from Regulus on August 8 – 11
Mercury, Regulus, and Jupiter in twilight

Jupiter and Regulus are less than a degree apart on August 8, 2015.


Saturn continues to drift slowly from Libra to Sagittarius this month. Look for it with a first quarter Moon on August 22.
The Moon and Saturn near Scorpio

The Moon passes Saturn


Opposition is at roughly 03:00 UT September 1, which is about 11 PM Aug. 31 here. That means Neptune is closer the Earth at the end of this month and beginning of September than at any other time this year, so it’s your best chance to see it as something more than a faint dot. There isn’t much around it to guide you though, so you’ll probably want some more detailed maps than I can post here, or (of course) a computerized ‘scope.
Neptune on August 31

Neptune on August 31

Deep Sky

Double Stars

The nice thing about stars is that they are point sources. You just look at the magnitude and you pretty much know whether or not you’ll be able to see it. However, stars don’t look too much different though the ‘scope than naked eye, so they aren’t the most exciting things to look at. Unless it’s not just 1 star…
The easiest double is Alcor & Mizar. It’s a naked eye double in the handle of the Big Dipper. A telescope reveals Mizar as a double, and a fourth star in the system.
Albireo is also fairly easy to find, at the head of Cygnus. A telescope reveals it as a yellowish star and a blueish star (though different people will see the colors differently.) Nearby, you can test the resolution of your ‘scope on Epsilon Lyrae, the double-double. A small ‘scope separates it into two stars, which each resolve as two stars in a bigger ‘scope..

Globular star clusters

The summer skies are full of globular clusters. Three of the nicest are M13, M92, and M3. M13 and M92 are high overhead at the start of the month, one M3 is to the west. At the end of the month, M3 is low in the west and M13 and M92 are high in the west.

Open clusters

The summer Milky Way is high overhead, and of course it is full of open clusters. Two of the nicest clusters are M6 ( the butterfly cluster) and M7 (the northern jewel box). They transit at 9 PM at the end of the month, when it’s still twilight, so look for them soon!


Bright skies make it really hard to see nebulae. M57 (the ring) is a nicely compact object, so even though it’s faint you might be able to pull it in with a small ‘scope. M27 (dumbbell) has a brighter magnitude, but it’s also bigger, so it has a lower surface brightness, which makes it much harder to see in urban skies. If you happen to have a good night, or a nebula or oxygen filter, it’s worth trying. Also worth trying is M8, the lateen nebula. Unlike M27 & M57, which are the remnants of dying Sun-like stars, M8 is a star forming region. In dark skies, M8 is visible to the naked eye as a large fuzzy patch in Sagittarius, sometimes even referred to as the steam from the tea pot. Binoculars are enough to pull out the associated star cluster and bright inner region, even under fairly bright skies. A small ‘scope might pull in some of the wider dust lanes.


One of the great things about August is the return of M31. Look for it low in the northeast at 10 PM at the beginning of the month, or mid height in the east-north-east at the end of the month.
Full sky map on August 15, 10 PM.

Full sky map on August 15, 10 PM.



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