Vern’s Weblog

Sky this Week for Jan 27th to Feb 2nd, 2008


International Space Station
Some nice bright passes of the ISS in the early evening this week.
Wed. Jan 30th magnitude -2.5 appears in the southwest at 6:31:07 pm and disappears in the east-northeast at 6:34:42
Thurs. Jan 31st magnitude -1.1 appears in the west at 6:52:35 and disappears in the north-northwest at 6:55:28 pm
Fri. Feb 1st magnitude -2.3 appears in the southwest at 5:38:37 and disappears in the east-northeast at 5:44:11 pm
Sat. Feb 2nd magnitude -1.3 appears in the west-southwest at 5:59:56 pm and disappears in the northeast at 6:05:16 pm
Sun
No active regions are visible on the disk as of today Jan 27th.
For those of us at 40 degrees north, the sun rises around 7:15 am on Sunday to 7:10 am next Saturday. It sets bit later from 5:16 to 5:23 pm

Moon
The Moon will be in third quarter on Tuesday, Jan 29th at 10:03 pm MST
By Saturday Feb 2nd it will be visible as a thin waxing crescent low in the southwest before dawn
Planets
Mercury sinks lower in the west after sunset this week. By Saturday it sets only about 45 minutes after the sun. This week is about the last chance to view it for a while.

Mars is getting further away, smaller and a bit dimmer now that it is past opposition. Around 9pm it is up high overhead in constellation Taurus.

Saturn is getting closer and brighter. It will be at opposition on February 24th. Around 9 pm, look for it in the east in constellation Leo. At that time it is nearly directly below the star Regulus.

Look for the planet Jupiter before sunrise in constellation Sagittarius.

Venus can be seen shining brilliantly at magnitude -3.9 in the constellation Sagittarius.

Asteroids
Monday evening Jan 28th, look for the asteroid 2007 TU24. The asteroid is about 800 feet across and passes fairly close to earth at a distance of 344 thousand miles away at the closest (around 1:30 am MST Jan 29th). It is about 10.2 magnitude at the brightest and moving fast across the sky so it will be difficult to locate. Use a star chart program to plan its location at given points in time, say every 10 minutes, so that you can locate that point and then watch it cross the field of view of your telescope.

Comets
Comet 17P Holmes is now about 1-1/2 degrees across. It will probably be difficult spot unless you are in a dark sky location. It is below the Star Algol in constellation Perseus

Comet 46P Wirtanen is moving through constellation Pisces. It is magnitude 9.2 in brightenss.

Dark Sky
Since the new moon is mid-week on Feb 6 we get dark sky weekends both this week and next as well.

Around 9 pm look to the northeast and locate the constellation Ursa Major, commonly referred to as the Big Dipper. Mentally draw a diagonal across the bowl of the dipper between stars Phad and Dubhe. Then extend it in the same direction and the same length. With even binoculars or a small telescope you should see the galaxy Messier 81. With an 8 inch telescope or larger some of the spiral structure can be seen. The view is stunning in dark skies through a large aperture scope such as 30″ dob.

While you are in the neighborhood, slew 38 arc minutes north and locate Messier 82. This is an irregular galxy which we view edge on. In scopes 8 inches in aperture or larger show a dark lane which nearly bisects the halo. In larger scopes, bright knots can be seen along the axis of the cigar shape.

Summary of some things to see in the sky this week, Jan. 20 to 26, 2008.
(Ooops had to do a panic edit, lunation 13.7 is not 13 hours, but 13 days, sigh [blush]).

International Space Station
No good passes this week.
Sun
For those of us around 40 degrees north latitude, the sun rises earlier from 7:19 am to 7:16 pm. It sets later each day as well from 5:08 pm to 5:15 pm. No regions are currently visible on the solar disk as of today (Sunday).

Moon
Sun Jan 20th: lunation 12.7 days
Craters Pythagorus and Wargentin

Mon Jan 21st: lunation 13.7
Crater Grimaldi

Tues Jan 22nd: lunation 14.7
The Moon will be full on Tuesday Jan 22nd at 06:35 am. Look for rays extending from prominent craters and bright albedo features.

Wed Jan 23rd: lunation 15.7
Still full, look for rays and bright albedo features.

Thurs Jan 24th: lunation 16.7
Take a look at lunar craters Petavius, Langrenus, Cleomedes, and Endymon. Mare Crisium should show some nice detail.

Fri Jan 25th: lunation 17.7
Craters Atlas, Hercules, Messier, Taruntius. Locate Vallis Rheita.

Sat Jan 26: lunation 18.7
View Mare Tranquillitatis and Rupes Cauchy. Checkout craters Fracastorius, Piccolomini, & Cauchy Omega

The Planets
Look for the planet Mercury low in the west-southwest about an hour after sunset. It is magnitude -0.7 magnitude in brightness early in the week and then dims to about magnitude 0. It will appear as a small crescent moon in your telescope. Mercury is at greatest eastern elongation on Jan 22nd.

The planet Mars is in constellation Taurus.

Saturn is getting closer and larger and is always great to view in your telescope. Our view of the rings changes over the years due to the relative positions of Saturn and Earth. The tilt of the rings will reach a maximum this year of about 15 degrees in February. The tilt has been decreasing since March of 2003 when it was near the maximum of 27 degrees. The rings will be at a minimum tilt angle to Earth in Aug & Sept of 2009 and extremely difficult to see.

Venus is low in the eastern sky. It appears in a telescope as waxing crescent moon, about 4 days past full.

Jupiter is still very low in the southwest. It rises around 5:40 am by the weekend in the constellation Sagittarius.

Dark Sky
Not much until the weekend. You can get some early evening views before the moon rises around 10 pm Saturday.

Comets
Comet 17P Holmes passes very near (9′ center-center) the star Algol in constellation Perseus early Tuesday morning, it will be difficult to spot in the bright moonlight.

Comet 46P/Wirtanen is moving further northeast in constellation Pisces. It is currently about magnitude 9 in brightness

International Space Station
Some bright passes this week about an or so before sunrise.
A magnitude -1.3 pass at 6:28:39 am on Wed Jan 16 from the northwest, disappears in the east at 6:33:40
A magnitude -2.4 pass at 6:48:08 on Thurs Jan 17 from the west-northwest, disappears in the east-northeast at 6:53:42
A magnitude -1 pass at 6:35:48 on Fri Jan 18 from the west-northwest, disappears in the east at 5:38:19
A magnitude -2.6 pass at 5:54:59 on Sat Jan 19 from the west-northwest, disappears in the southeast at 5:58:21
Sun
For us at 40 degrees north latitude, the sun rises earlier from 7:22 to 7:20 am and sets a little later as well from 5 to 5:06 pm. No active regions are currently visible on the solar disk (Sunday).
Planets
Mercury is constellation Capricornus -0.79 to -0.69 magnitude 5.63 to 6.37 arc sec
sets 6:13 to 6:35 pm in the southwest.

On Monday, Jan 14 th around 12:03 pm, the Messenger space craft will do its first flyby of the planet Mercury.
Messenger was launched on Aug 4, 2004 and has made a series of passes at Venus to get rid of velocity. Look for some great images of parts of Mercury never before observed.

Venus rises 4:48 to 4:59 am in constellation Ophiuchus -3.93 to -3.91 mag, 13.62 to 13.23 arc sec across
Moon
The Moon is in first quarter at 12:46 pm MST on Tues, Jan 15th. The terminator will be passing close by the following features on days indicated.
Jan 14 Monday lunation 6.7: crater Cassini, Mons Hadley
Jan 15 Tuesday lunation 7.7: Montes Alpes, Montes Alpinnius, Rima Hadley, Valis Alpes
Jan 16 Wednesday lunation 8.7: crater Copernicus, Fra Mauro, crater Plato, crater Tycho
Jan 17 Thursday lunation 9.7: Sinus Iridum, crater Longomontus
Jan 18 Friday lunation 10.7: craters J. Herschel, Kepler, and Gassendi, Montes Jura
Jan 19 Saturday lunation 11.7 craters Aristarchus and Schickard, Oceanus Procellarum

Mars is in constellation Taurus, It dims from magnitude -1.17 to -0.99 and shinks from 14.3 to 13.6 arc sec in diameter. On Saturday the Moon and Mars come close to each other, about 15 arc minutes (limb to center of Mars) at closest approach around 3 pm.

Jupiter is just above top of the teapot (constellation Sagitarius) magnitude -1.69 to -1.69 diameter is 32.08 arc sec. It rises about 6 am, very low in the southeast.

Saturn rises at 8:12 am Saturday in constellation Leo, 0.77 magnitude in brightness and the disk is 19.6 arc sec across.

Dark Sky
Not much this week
Comets
17P Holmes is still around in Perseus but will probably tough to spot because of its large size and interence from the moon.

46P Wirtanen is in the lower part of constellation Pisces. Ephemeris predicts it to be magnitude 9.5. See SkyHound.com comet pages for more details and charts.

The following is a brief summary of some things to check out in the sky, during this week January 6 to January 12.

International Space Station
There are no bright passes this week.
Sun
The sun rises at 7:32 am this week for us at latitude 40 degrees north. It starts setting a little later this week at 4:53 pm to 4:59 pm.
A high latitude sunpot with a magnetic polarity opposite those currently being observed appeared on the solar disk on Janurary 3rd. Such an occurence always marks the beginning of the next solar cycle according to the folks at the NOAA Space Weather Prediction Center in Boulder, Colorado. This region 10981 is currently located in the north central region of the solar disk. It is very small and decreasing in size. It will probably not be visible in a few days.

Moon
The moon will be “new” on Tuesday at 4:37 am MST. On Wednesday you might be able to spot a very thin crescent moon very low in the southwest before it sets at 6:05 pm at age 1.56 days.
On Thursday you should have no difficulty spotting the 2.6 day old moon which sets at 7:22 pm. Look for crater Langrenus slightly south of the center of the crescent. Mare Crisium should be a good to view in your telescope as the rising sun on the moon surface casts long shadows which increases contrast. See if you can locate the 31 mile wide block known as Cape Agarum in the southeastern part of Mare Crisium. This is the highest point in Mare Crisium and rises 18 thousand feet above the plane.
On Friday Jan 11th, the moon sets at 8:30 pm. Locate craters Messier and Messier A in northern Mare Fecundiatits. Note the remarkable parallel rays extending westward. These rays were probably formed by collisions with different objects impacting at very shallow angles of 1 to 5 degrees .
On Saturday the moon will be 4.6 days past new. In the north look for the remarkable craters Hercules and Atlas. Mare Fecunditatis is in full view as well.
Planets
Mercury appears low in the southwestern sky after sunset this week in constellation Capricornus. It sets at 6:09 pm on Saturday.

Venus is visible early in the morning low in the southeastern sky in the constellation Scorpius; it is a briliant -3.9 magnitude in brightness and 13.7 arc sec across.

Mars continues a westward trek in constellation Taurus. The disk shrinks from 15.1 to 14.4 arc across and its brightness dims from magnitude -1.4 to -1.2 . On Saturday evening around 11 pm, the martian feature Mare Serenum will be visible near the central meridan.

Jupiter makes its debut about an hour before sunrise, very low in the southwest in the constellation Ophiuchus.
Dark Sky
This a great week to view objects in a dark sky. Located very high up in the sky (around 65 degrees) is the constellation Taurus. Look for a ‘V’ shape asterism of dim stars. The point of the V points to the lower right with a bright orange-red star marking the left eye of Taurus the bull. This “V” shape is a cluster know as the Hyades. Look even farther up and to the right and spot Messier 45, a small cluster of 6 to 9 stars, depending on how dark your skies are. This cluster is also called the Pleades or the seven sisters. It is one of the most beautiful objects to view in the night sky with binoculars or wide field telescope. Look for swirls of nebulosity surrounding the two brightest stars. Also in Taurus is Messier 1, a supernova remnant which is also known as the crab nebula.

Above Taurus is the constellation Auriga which contains three other objects on Messier’s list,the open clusters M36, M37 and M38. These clusters are easily spotted with binoculars under reasonably dark skies.
Comets
Comet 17P Holmes is in constellation Perseus above the star Algol. On January 22nd it will pass within about 8 arc minutes of Algol — photo op!.
Comet 8P Tuttle is moving southward in constellation Cetus. This is about the last week for us in the northern hemisphere to view it. It will be getting very close to the southern horizon in another week.

Here is an attempt to make a video out of the Sky this Week post..