Vern’s Weblog

Fall has arrived, the autumn equinox occurred at 4:37 am MDT this morning. Our nights are getting longer, the Sun rises before 7 am and sets before 7 pm as well. It is fairly dark around 8. If we look to the east we can see that the great square of Pegasus is already high up and the stars in the northern cross of Cygnus are overhead. The Moon interferes with our views of the night sky this week. That is no excuse though, to not to get your scope out of the garage. The Moon is a wonderful object to explore. I’d suggest starting your exploration of the Moon by locating the targets listed in the Astroleague’s Lunar Club program. For those more advanced, the Astroleague Lunar II program is challenge that only 3 people have accomplished.

International Space Station
There are a number of good ISS passes this week but all are in the early morning. Here is a list of the brightest ones:

Sept. 25 the ISS rises in the NW at 5:48:59 am and disappears in the ESE at 5:54:24 am (magnitude -1.1)
Sept. 26 the ISS rises in the WNW at 6:10:42 am and disappears in the SE at 6:16:19 am (magnitude -2.3)
Sept. 27 the ISS rises in the ENE at 5:00:43 am and disappears in the ESE at 5:02:56 am (magnitude -0.7)
Sept. 28 the ISS rises in the SSE at 5:22:32 am and disappears in the SE at 5:24:52 am (magnitude -2.0)
Sept. 29 the ISS rises in the SSW at 5:44:31 am and disappears in the S at 5:45:43 am (magnitude -0.4)

Sun

This week the Sun rises at 6:51 am to 6:57 am MDT and sets 6:59 pm to 6:49 pm MDT. No regions are visible today (Sunday), in fact none have been visible since Sept. 4. Solar activity is expected to remain at very low levels this week.

Moon

The Moon is full on Wed. Sept 26 at 1:45 pm MDT. Since it occurs close to the autumn equinox, it is called a “Harvest Moon”. The following are some Lunar II Club targets for this week:

Sun Sept 23: Mons Rumker, Wargentin
Mon Sept 24: Bailly, Cruger, Grimaldi Basin, and Rima Cauchy
Tues Sept 25:
Wed Sept 26:
Thurs Sept 27: Mare Undarum, Montes Corillera, Mare Spumans
Fri Sept 28: Messier, Vallis Rheita
Sat Sept 29: Sinus Concordiae, Taruntius

Planets

Mercury appears very low in the SW early in the week and sets about a 50 minutes after sunset, magnitude -0.0 and 6.2 arc sec in diameter. It is at its greatest elongation on Saturday but sets earlier (7:38 pm) and will be very difficult to locate.

Venus shines brilliantly at magnitude -2.8 before sunrise, high up in constellation Leo; it rises around 3:30 am. It appears in a telescope as a thin crescent.

Mars rises shortly after 11 pm MDT and moves to constellation Gemini this week. By Saturday it will -0.1 magnitude in brightness, 9.7 arc sec across, and 87% illuminated.
Best time to view Mars is when it is high up after 3 am. Early in the week the martian features the features Solis Locus, Olympus Mons, Mare Sirenum, and Mare Cimmerium are in our view around that time. Later in the week are Mare Erythraeum, Vallis Marinerius, and Solis Lacus. See Sky and Telescope’s Mars profiler for other times and additional information. By Saturday there will only be 88 more days till opposition on Christmas eve!

Jupiter is the brightest object in the SW after dark in constellation Ophiuchus. For us in the Denver area, its down low in the turbulence over the mountains so its tough to see much detail other than a band or two. It sets before 10:30pm. Jupiter’s Great Red Spot crosses the center of the disk at the following times:

Sept. 23 at 9:19 pm
Sept. 26 at 6:50 pm
Sept. 28 at 8:29 pm

Saturn rises low in the ENE around 4 am just below and left of star Regulus in constellation Leo and is magnitude +1 in brightness.

Uranus is in constellation Aquarius, magnitude 5.7, and 3.6 arc-sec in diameter.

Neptune is in constellation Capricornus, magnitude 7.8, and 2.5 arc-sec in diameter.

Dark Sky

Not this week!

This entry was posted on Sunday, September 23rd, 2007 at 3:59 pm and is filed under Astronomy, Sky this Week. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.