Vern’s Weblog

 The following is a list of some astronomical objects  and events to watch this week, Sept. 9 thru Sept. 15, 2007. Some of the events and times given are specific to the Colorado front range (40° N and the MDT timezone).

Highlights

• Dark sky weekend yet again!
• Excellent ISS passes early in the morning, Tues at 5:23 am and Wed at 5:47 am

International Space Station
Tues Sept. 11 ISS appears at 05:25:28 in the SSW and disappears at 05:29:31 in the East (magnitude -2.1)
Wed Sept. 12 ISS appears at 05:47:00  in the West and disappears at 05:51:29 in the NE (magnitude -1.6)

Sun

This week the Sun rises  at 6:36 am to 6:40 am MDT and sets 7:26 pm to 7:17 pm MDT.  No regions are visible today (Sunday). Solar activity is expected to remain at very low levels this week.

Moon

The Moon is in new on Tues Sept 11 at 6:44 am. The Moon sets very early this week so is not in good position for telescope viewing.

Planets

Mercury appears very low, difficult to spot, nearly straight west during bright twilight after sunset.

Venus is visible in the constellation Cancer in the east about two hours before sunrise, it is quite bright at magnitude -1.9.

Mars rises 11:31 pm to 11:21 pm MDT in constellation Taurus. By the end of the week it will +0.1 magnitude in brightness, 9.1 arc sec across (5% larger), and 86% illuminated.
Best time to view Mars is when it is high up (around 4 to 6 am).  The martian features Syrtris Major, Mare Serpentis and Sinus Sabeaus are visible early in the week at that time. Later in the week the features Mare Cimmerium, Mare Tyrrhenum, and Syrtis Major are in our view. SeeSky and Telescope’s Mars profiler for other times and additional information.

Jupiter is in the SSW  after dark in constellation Ophiuchus. Jupiter’s Great Red Spot  crosses the center of the disk at the following times: (sets 10:54 to 10:36 pm)
Sun. Sept. 9 at 7:42 pm
Tues. Sept. 11 at 9:21 pm
Fri. Sept. 14 at 6:52 pm

Jupiter is setting around 10:30 pm now so our views of it are limited, especially against the unstable air over the mountains to our west (from here in the front range in Colorado).  Best time to look is during early twilight, shortly after sunset, when it is still high up.

Saturn rises very low in the ENE around 5:15 am just below and left of star Regulus in constellation Leo.

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.

Pluto is in constellation Sagitarrius, magnitute 14, and 0.1 arc-sec in diameter.

Comets

Comet 29P/Schwassmann-Wachmann is in constellation Auriga and is magnitude 11.7 in brightness with a 2 arc-min coma. See finder chart on the Skyhound comet page.

Asteroids

There are 17 asteroids brighter than magnitude +11 this week. Locations below are for Sat. Sept. 15 at 10:30 pm MDT.

     Name      Const      RA        DEC     Mag
   1 Ceres       TAU   03:35:35 +09 26′00″  8.3
   2 Pallas      AQR   22:17:31 +01 25′04″  8.9
   8 Flora       ARI   03:57:03 +11 19′34″  9.4
  10 Hygiea      PSC   00:40:53 +10 13′02″ 10.4
  12 Victoria    PSC   00:57:42 +18 58′22″  9.7
  13 Egeria      PSC   01:48:36 -02 51′28″ 10.8
  15 Eunomia     AUR   06:55:59 +29 30′15″ 10.0
  27 Euterpe     AQR   20:56:40 -19 12′49″ 11.0
  29 Amphitrite  TAU   03:48:14 +25 23′14″ 10.0
  30 Urania      AQR   22:34:58 -06 25′10″ 10.0
  80 Sappho      AQL   19:41:25 -07 22′36″ 10.9
115 Thyra       AQR   22:25:35 +04 32′14″ 10.0
185 Eunike      AQR   00:03:15 -15 07′00″ 10.8
194 Prokne      AQR   21:29:51 -12 37′04″ 10.2
230 Athamantis  AQR   22:02:20 +05 08′22″ 10.3
349 Dembowska   AUR   04:46:14 +25 32′06″ 10.7
511 Davida      CET   02:27:51 -09 16′18″ 10.8

Dark Sky

Since the Moon sets before twilight ends this weekend we can have some more time out in the dark with dim fuzzies.  This time of year we can view the summer stuff like the Lagoon Nebula in Sagittarius in the early evening, the Veil Nebula in Cygnus high overhead at 10 pm, M31 in Andromeda around 2 am,  and M42 in Orion around 4am.  A view of Andromeda with just binoculars on a clear, crisp night, in a dark sky should not be missed. It is by itself worth the drive!

Meteor Showers

The September Perseid meteor shower is Sept. 5 to Sept. 16 with peak on Sept 9. This is a minor shower, a max of 5 per hour are expected at peak times (before dawn on Sept. 9).
Sporadic meteor rates continue to increase this month, around 4 might be seen per hour after dark to about 7 per hour around 4 am. Visit the American Meteor Society for more information.

NGC 891 in Andromeda is a unbarred spiral seen edge on from our vantage point in space. It has a thin dark dust lane bisecting the entire cross section. It is a stunning, show piece object when viewed in a large aperature telescope from a dark sky location.

Fortunately we had access to both last Friday evening. We went to the Pawnee National Grasslands near Briggsdale, CO to get away the light pollution and enjoy some nearby dark sky. Gary brought out his 30 inch dob Telekit so we had plenty of aperature to view NGC 891, not to mention many other great objects. 

The above image taken with Celestron Nexstar 11 telescope, F3.3 focal reducer, and Stellacam II video camera. Stellacam II set at gain 14/14 and 256 integration (8 sec).  Registax4 used to flat field correct, dark frame subtract, align, and stack 30 frames. Conditions were great, sky was totally clear, wind 0-5 mph, low humidity, temperature 54°F, and turbulence between 5 and 6/10.

Mare Insularum (Lunar II target 32) is located between lunar crater Kepler on the west and Copernicus on the east. It  is bordered on the north by the Carpatus mountains  and maybe around crater Lansberg in the south (not shown here).  In the image below Copernicus is the huge crater on the right (east); Crater Kepler is just out of view on the left;  Crater Reinhold is near bottom center.  It appears to be a relatively flat region. Rays from both Copernicus and Kepler extend across the mare.

Image acquired early Sept. 4, at 5am., Louisville, CO. Celestron Nexstar 11 Telescope and Phillips Toucam 840K webcam. One minute video at 20 fps aligned and stacked with Registax4. Enhanced, cropped, and labeled with Photoshop Elements2. Sky was clear, temperature 59°F, 0-1mph wind, transparency excellent, turbulence between 5 and 6/10.

The Moon at lunation 22.54 days.  Not being a ‘morning’ person, I tend to not image the Moon much after its full phase.  I should though, the air tends to be steadier here around 3-4 am and its usually clear as well.  Its been cloudy in the evening here a lot lately as well — hence the motivation to get out of bed at 3am and take an image or two.

Image taken from Louisville, CO at 05:55 am MDT with Celestron Nexstar 11 telescope, F6.3 focal reducer, and Canon Xti camera. Camera settings were ISO 400, 1/640 sec exposure. Aligned and stacked 32/40 frames with Registax4 (wavelet layer 1 at 8, layer 2 at 6).  The sky was clear, temperature was 59°F, 0-1 mph wind, transparency was excellent, and turbulence varied from 5 to 6.

 The following is a list of some astronomical objects  and events to watch this week, Sept. 2 thru Sept. 8, 2007. Some of the events and times given are specific to the Colorado front range (40° N and the MDT timezone).

Highlights

• Dark sky weekend!
• Western Nebraska Star Gaze near Bridgeport, Nebraska Sept 7-9

International Space Station
No good passes this week.

Sun
This week the Sun rises at 6:31 am to 6:36 am MDT and sets 7:34 pm to 7:24 pm MDT. Only the small region 10970 is currently visible slightly west of center. Solar activity is expected remain at very low levels this week.

Moon
The Moon is in 3rd quarter on Monday Sept 3 at 8:32 pm. New moon is Sept 12 at 5:54 pm.

Planets
Mercury appears very low, nearly straight west during early evening twilight later this week.

Venus is visible in the constellation Cancer low in the east about an hour before sunrise, it is quite bright at magnitude -1.1.

Mars rises 11:55 pm to 11:46 pm MDT in constellation Taurus. By the end of the week it will +0.2 magnitude in brightness, 8.4 arc sec across, and 86% illuminated.
Best time to view Mars is just before sunrise when it is high up (around 5 am). The martian features Sinus Meridiani and Sinus Sabeaus are visible early in the week at 5am. Later in the week the features Sinus Sabeaus and Syrtis Major are in our view.

Jupiter is in the SSW after dark in constellation Ophiuchus. Jupiter’s Great Red Spot crosses the center of the disk at the following times:

Tues Sept. 4 at 8:33 pm
Thurs Sept. 6 at 10:11 pm

Jupiter is setting around 11pm now so our views of it are limited, especially against the unstable air over the mountains to our west (from here in the front range in Colorado). Best time to look is during early twilight, shortly after sunset, when it is still high up.

Saturn rises very low in the ENE around 5:15 am just below and left of star Regulus in constellation Leo, later in the week. It was in conjunction with the Sun on Aug 21.

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.

Pluto is in constellation Sagitarrius, magnitute 14, and 0.1 arc-sec in diameter.

Comets
No reasonably bright comets are visible this week.

Asteroids
There are 8 asteroids brighter than magnitude +10 this week. Locations are for Sat. Sept. 8 at 10:30 pm MDT.

     Name        Const           RA          Dec      Mag

     1 Ceres     Cetus        03:34:11   +09 28′55″   8.5  

     2 Pallas    Pegasus      22:22:26   +02 56′07″   8.9  

     4 Vesta     Scorpio      16:50:40   -22 08′56″   7.3  

     8 Flora     Cetus        03:49:46   +11 20′04″   9.5  

    12 Victoria  Pisces       01:01:52   +19 30′33″   9.8  

    15 Eunomia   Gemini       06:43:39   +29 50′53″  10.0  

    30 Urania    Aquarius     22:41:11   -05 54′15″   9.8  

   115 Thyra     Pegasus      22:32:58   +04 35′37″   9.9

Dark Sky
Since the next new Moon falls mid week, we get two dark sky weekends in a row. The constellation Cygnus, the swan, is high overhead and the great square of Pegasus is visible in the east. The late summer sky offers many fascinating targets for us to see — M57 the ring in Lyra, M27 the Dumbbel nebula in Aquilla, and M11 the Wild Duck Cluster in Scutum to mention just a few. This weekend we should get some outstanding views of the supernova remnant Veil NGC 6993 and 6995 to the east, and NGC 6960 to the west. The Crescent Nebula, NGC 6888, will be great to revisit as well.

Meteor Showers
The September Perseid meteor shower is Sept. 5 to Sept. 16 with peak on Sept 9. This is a minor shower, a max of 5 per hour are expected at peak times (before dawn on Sept. 9).
Sporadic meteor rates continue to increase this month, around 4 might be seen per hour after dark to about 7 per hour around 4 am. Visit the American Meteor Society for more information.