Sky this Week
The following are a few of the many astronomical objects that may be viewed during the
week of March 30 to April 5, 2008.
International Space Station
The ESA Automated Transfer Vehicle will be maneuvering
close to the ISS this week. Unfortunately, the passes over
the continental United States are far north this week.
Sun
Three regions are currently visible on the solar disk. Region 10989 is located
near the center of the disk. Further west (right) is 10988, and then 10987.
Here is a look at the sun in h-alpha. An h-alpha telescope reveals features on
the sun’s disk not visible in white light. In the image are some ephemeral regions where magnetic
flux tubes emerge on the surface. These appear as bright plage regions. Also visible is a filament
to the southeast of region 10988. Flaments are relatively cool, dense gas that is suspended in magnetic
loops above the surface of the sun. When we look down on them they appear as dark lines as the material
is cooler than the hot photosphere below. When we see them in profile against a dark
sky they are called prominences. This one appeared on the southwest limb on saturday.
On March 30 sunrise was at 6:49 am and sunset was at 7:24 pm MDT On Saturday, April
5th, sunrise is 6:39 am and sunset is 7:30 pm MDT
Moon
New moon is on Apr 5 at 9:55 pm MDT
Planets
Mars is in constellation Gemini. It is +0.9 magnitude in brightness and 6.8
arc sec across.
Saturn is in constellation Leo. It is +0.8 magnitude in brightness
and 20.5 arc sec across.
Jupiter is in constellation Sagittarius. It is -2 magnitude
in brightness 37.9 arc sec across. It will be at opposition on July 9th. Jupiter’s
great red spot crosses the center on Tues April 1st at 5:14 am. The GRS is visible
for about an hour before and after the central meridian crossing.
Asteroids
There are 3 asteroids brighter than magnitude 10, all are currently in the
constellation Virgo.
5 Astraea magnitude 9.4
7 Iris magnitude 9.4
41 Daphne magnitude 9.3
Dark Sky
Dark sky weekend is coming up. Those of us at 40 degress north latitude
will get 8 hrs and 6 minutes of astronomical darkness.
By 10 pm the constellation Coma Berenices is in good position.
Locate the 5th magnitude star 6 Coma Berenices which is just 6
degrees east of star Denebola in Leo’s tail. Just west of this star
is galaxy M98. Messier 98 is a blue-shift galaxy approaching us at
544 thousand miles per hour. It is about 70 million years away
though so the collision is not imminent. Form a south east pointing
triangle with star 6 and the 6th magnitude star to the northwest to
locate M99. Messier 99 is a large red shift galaxy moving away from
us at a speed of 5.3 million miles per hour.
Back to 6 Coma Berenices, follow a string of 6th magnitude stars to
the northeast, between the 3rd and 4th one is M100. Messier 100 is a
fine, face-on galaxy with a small, bright core surrounded by a 6 arc
min wide bright halo.
Locate Alpha Coma Berenices and star hop 5th magnitude stars 36, 27,
24, and 11 Coma Berenices. About half-way between 24 and 11 lies
M85.
Those who can stay awake all night have a second chance to locate
all 110 Messier objects this weekend.
Comets
17P Holmes is in constellation Perseus; it is magnitude 5.7 in brightness and 70′ across
46P Wirtanen is in constellation Auriga; it is magnitude 10.2 in brightness and 5.1′ across
C/2008 C1 Chen-Gao is in constellation Auriga; it is
magnitude 10.2 in brightness and 2.5′ across
C/2007 W1 Boattini is in constellation Corvus; it is magnitude 10.9 in brightness and 1.9′ across