Sky this Week April 13 to April 19, 2008
Some astronomical objects to view up in the sky during the week of April 13 to 19, 2008.
INTERNATIONAL SPACE STATION
No bright passes this week.
SUN
Our closest star, the Sun, is currently at solar minimum As of today,
Sunday, there are no active regions visible on the solar disk.
For those of us at 40 degrees north latitude the sun rose Sunday morning
April 13th at 6:27 am and set at 7:38 pm MDT.
Next Saturday the sun will rise at 6:18 am MDT and set at 7:44 pm MDT
PLANETS
If we look toward the southwest about an hour after sunset, we can
see the planet Mars about half way between the horizon and the zenith in in
the southwest. It is currently in the constellation Gemini. It is now 1.5 AU
or 139 million miles from earth. It appears quite small in a telescope,
about 6.2 arc sec across in the eyepiece and is magnitude 1.1 in brightness.
The disk is 90% illuminated.
To the south the planet Saturn is visible high up in the constellation Leo.
Saturn is 812 million miles (8.7331 au) from Earth. It is 19 arc sec across
and 0.9 magnitude in brightness It is always great to view in a telescope.
On Saturday Saturns largest Titan (magnitude 8.3) will appear in appear in
the eyepiece about 1.5 arc minutes to the east of saturn. Saturns moon Rhea
(magntiude 9.6) is about 1 arc minute to the east. The 10th magnitude moons
Tethys (above) and Dione (below) are about 0.5 arc minute to the east as
well.
Early morning in the twilight before sunrise is currently the best time to
view and image the planet Jupiter this week. At that time it will be to the
south in the constellation Sagittarius. It is magnitude -2.1 in brightness
and 37 arc sec across. It is now about 4.8 au or 462 million miles away. It
will be getting closer, brighter and larger over the next few months. It is
at opposition and closest to the earth on July 8.
Jupiter’s Great Red Spot crosses the center of the disk at the following times this week. It is visible for about an hour before and after the central meridian crossing,
Tue April 15 at 06:47 am (MDT)
Wed April 16 at 02:38 am
Fri April 18 at 04:17 am
Sun April 20 at 05:55 am
MOON
This week is a good time to view the Earth’s moon. Aim your telescope or binoculars along the terminator. The terminator is the line on the moon’s disk between light and dark. The sun is rising at that location and casting long shadows which emphasize hills, craters, domes, and other geologic
features.
Mon. April 14 : Lunation 9 (that is 9 days after new): Take a look a the spectacular crater Copernicus with binoculars or telescope of any size. Copernicus is one of the most prominent craters on the moon. It is a relatively young crater have been formed only about a billion years ago by a massive impact. The central portion of the crater is about 58 miles (93 km) across. There are 3 terraces visible along inner wall of the crater. The 3 central peaks are about 3900 feet high. Lunar1 targets: Mare Frigoris, Mare Imbrium, Copernicus, Bullialdus. Longomontanus
Tues April 15: Lunation 10. Perhaps one of the most beautiful features on the Moon, Sinus Iridum also called “the Bay of Rainbows” may be viewed. Sinus Iridum is a 162 mile (260 km) wide impact crater in which one side subsided and then filled with lava. To its north are the Jura mountains. The
Promotorium Laplace on the west and Promotorium Heraclides on the east are local high spots rising about 7900 feet (2.4km) above the bay..
Wed April 16 Lunation 11: (Lunar1 targets) Aristarchus, Kepler, Oceanus Procellarum, Gassendi.
Thurs April 17 Lunation 12: (Lunar1 targets) Sinus Roris, Vallis Schroter, Billy, Schickard, Reiner Gamma
Fri April 18 Lunation 13: Look for Rays and bright albedo features
COMETS (brightner than magnitude 12)
17P Holmes is in constellation Auriga, the coma is 70 arc min and is magnitude 5.6
C/2007 W1 Boattini is in the constellation Crater. It is magnitude 8.8 and coma is 8.2 arc min across
C/2008 C1 Chen-Gao is in the constellation Orion. It is magnitude 10.2 and coma is 8.2 arc min across
C/2006 Q1 McNaught mag 11.1 and coma is 1 arc min across
46P Wirtanen is in the constellation Gemini. It is mag 11.5 in brightness and the coma is 3.9 arc min across
ASTEROIDS (brighter than magnitude 10)
All are in the constellation Virgo.
5 Astraea magnitude 9.8 It was discovered in 1845 by amateur astronomer Karl Hencke. The discovery of 5 Astrae led to the demotion of 4 other asteroids which considered to be planets at that time.
7 Iris magnitude 9.6
41 Daphne magnitude 9.4