Vern’s Weblog

The following is a brief list of some things to see in this sky, this week Feb 17 to Feb 23, 2008.

International Space Station

No bright passes this week.

USA 193

Sun Feb 17 at 5:56:59 appears in the SE and disappears in the ESE at 5:58:24, magnitude 3.8
Mon Feb 18 at 5:49:02 appears in the South and disappears in the ENE at 5:52:17, magnitude 3.1

Iridium 32

Flare at the Eclipse, Feb 20 7:28:22 pm, magnitude -4, essentially straight north (2 deg azimuth), altitude 52 degrees.

MOON

There is a total eclipse of the Moon this week on Wednesday, Feb 24th. The eclipse begins when the pale outer fringe of the Earth’s shadow touches the Moon’s edge at 6:05 PM MST. The shading will be subtle and won’t be very noticeable until the Moon reaches the Earth’s inner shadow at 6:43 PM. From about 7:30 to 8 PM is perhaps when the lunar eclipse will be the most impressive. The curved dark edge of Earth’s shadow will be seen creeping minute by minute across the lunar landscape. The Earth’s shadow will totally engulf the Moon from 8:00 to 8:52 pm MST. After totality ends at 8:52 PM, events unwind in reverse order; the Moon’s edge reappears in sunlight and gradually returns to full at 11:17 PM.

SUN

The Sun rises at 6:53 am on Sun Feb 17th and sets at 5:53 pm for those of us at 40 degrees north latitude. On Saturday, Feb 23rd it rises at 6:45 am and sets at 5:45 pm. There are no active regions visible on the solar disk.

PLANETS

The planet Mercury is visble low in the southwestern sky about an hour before sunrise. It is in constellation Capricornus; it brightens in magnitude from +1 to +0.5 and is 8.4 arc sec across.
The planet Venus is visible to the lower right of Mercury in the constellation Capricornus. It is -3.8 magnitude and 11.5 arc sec across.
Jupiter is visible in the morning sky as well. It is in the constellation Sagitarius and is -1.8 magnitude in brightness and 33.9 arc sec across.
The planet Mars is high overhead in the southwest in the constellation Taurus early in the evening. It is dims this week to magnitude +0.02 and is 9.7 arc sec across.
The planet Saturn is in the constellation Leo. It will be at opposition on Sunday Feb 24th. It is visible in the eastern sky as soon as it is dark. It is +0.56 magnitude in brightness and the disk is 20 arc sec across.

DOUBLE STARS

Our view of dark sky objects such as galaxies and nebulas is restricted during bright moon lit nights. Thats no reason to leave your scope in the basement. You can still observe the planets and double stars. For example, over in the constellation Orion double stars include Beta Orionis or Rigel, Mintaka or Delta Orionis, Iota Orionis, Zeta Orionis or Alnitak and Lambda Orionis or Meisa. Sigma Orionis is a triple system and Theta1 Orionis has 4 components. There are of course, many others. Check the Astroleague Double Star Club for a list of some great double and multiple stars to observe.

The following is a brief summary of some things to see in the sky this week, Feb 10 to Feb 16, 2008.

International Space Station

Tue Feb 12 at 6:20:28 pm the ISS appears in the NNW and disappears in the NE at 6:23:25 pm (-0.4 magnitude)
Wed Feb 13 at 6:40:29 pm the ISS appears in the NW and disappears in the NE at 6:43:32 pm (-1.4 magnitude)
Thurs Feb 14 at 7:00:44 pm the ISS appears in the NW and disappears in the SE at 7:03:45 pm (magnitude -2.5))
Fri Feb 15 two passes at 5:46:25 pm it appears in the NNW and disappears in the east at 5:51:25 pm (magnitude -1.3)
and at 7:21:27 pm it appears in the WNW and disappears in the SSW at 7:24:070 (magnitude -0.3)
Sat Feb 16 at 6:06:31 it appears in the NW at 6:06:31 pm and disappears in the SE at 6:12:08 (magnitude -2.5)

Sun
For us at 40 degrees north, the sunrises Sunday morning at 7:01 am and sets 5:32 pm. Next Saturday it rises at 6:54 am and sets at 5:39 pm. No regions are currently visible on the Sun’s disk.

Moon
Sun Feb 10 lunation 4 days: Craters Atlas, Hercules, Macrobius and Taruntius
Mon Feb 11 lunation 5 days: Craters Posidonius, Theophilus, and Picollomini. Luna Mara Tranquillatis
Tue Feb 12 lunation 6 days: Crater Aristoteles, Eudoxus, and Maurolycus
Wed Feb 13 lunation 7 days: in first quarter at 8:34 pm mst: Craters Casini, Aristillus, Hipparchus, Albategenius, and Werner. Check out the Montes Alpes and Montes Caucasus.
Thur Feb 14 lunation 8 days: Crater Plato, Archimedes, Alphonsus, Arzachel, and Tycho. Observe Rupes Recta, the straight wall.
Fri Feb 15 lunation 9 days: Craters Copernicus, Bulliardus, Fra Mauro, and Longomontanus.
Sat Feb 16 lunation 10 days: Check out Sinus Iridium, “the Bay of Rainbows” and Montes Jura.

Planets
Mars is up high in constellation Taurus in the early evening. By Saturday it will be 10.3 arc sec and -0.16 magnitude in brightness.
Saturn is in constellation Leo and is visible in the eastern sky as soon as its dark. It is 0.6 magnitude in brightness and the disk is 20 sec across. By 9 pm is it in good position for viewing and imaging.
Jupiter is in constellation Sagittarius and is visible in the eastern sky before sunrise. It is magnitude -1.77 in brightness and 33 arc sec across.
Venus is sinking lower each day. It is just barely visible above the southeastern horizon as the sky brightens before sunrise. It is -3.8 magnitude in brightness and 11.8 arc sec across.

Dark Sky
The moon interfers with our evening dark sky views this week.
Comets
17P Holmes is in constellation Perseus. It is currently 1.5 degrees or so across. It is still easy to spot in binoculars at a dark sky location.
46P Wirtanen is in constellation Aries and is magnitude 9.2 in brightness
29P Schwasmann-Wachmann is in constellation Auriga and is magnitude 11.4 in brightness
C/2008 C1 (Chen-Gao) is in constellation Cassiopeia and is magntiude 12.7 in brightness

The following is a brief summary of some things to see in the sky this week, Feb 3 thru Feb 9, 2008.

International Space Station

No bright passes this week.

Sun

For those of us at 40 degrees north latitude, the sun rises at 7:09 am on Sunday. It sets at 5:24 pm. By the following Saturday it rises at 7:03 am and sets at 5:31 pm.

One small region, number 10982, is visible just west of the center of the sun’s disk. It is currently decreasing in size and may disappear in a few days.

Moon

On Monday morning at lunation 27.1 the moon appears as a very thin waxing crescent low in the southeast below Venus and Jupiter.

The moon is new on Wed Feb 6th at 8:44 pm.

On Thursday the Moon sets at 6:17 pm at 0.9 days after new the Moon. It will be difficult to spot in the bright twilight. Only a thin patch near the center of the thin crescent may be visible.

By Friday at lunation 1.9, the Moon will easy to see low in the west.

On Saturday at lunation 2.9 look for the craters Endymon and Geminus in the north. The sun will be rising over the lunar plane of Mare Crisium. The long shadows emphasis lunar rilles and other features. Slew toward the south and look for craters Langrenus and Petavius.

Planets

Mars is high overhead in constellation Taurus in the early evening. It within a couple degrees of 2nd magnitude star Alnath which is shared by constellation Auriga and Taurus. On Saturday it will be -0.35 magnitude in brightness and 11 arc sec across the disk.

Saturn is in constellation Leo which is visible in the eastern sky around 9pm. It is 0.6 magnitude in brightness and the disk is about 20 arc sec across.

Jupiter and Venus may be seen low in the southeast before sunrise in the constellation Sagittarius. Jupiter is magnitude -1.7 and 33 arc sec across. Venus is magnitude -3.9 and 12 arc sec across.

Dark Sky

The upcoming weekend will have dark skies — the moon sets around 8:36 pm Saturday.

Nebula

The great Orion Nebula, Messier 42, is still high up in the south in the early evening. In dark skies and large aperture scopes subtle shades of green, blue and red may be seen.

Look eastward toward the constellation Gemini and locate the bluish-green nebula NGC2392 which is sometimes referred to as the Eskimo or clown face nebula. In small scopes it appears as a small faint oval patch surrounding a conspicuous 10.4 magnitude central star. In large aperture scopes the central star appears to be surrounded by disk which is split by an outer concentric ring.

Galaxies

The galaxies Messier 81 and 82 in constellation Ursa Major are in good position for viewing around 9 pm. By 10 pm the galaxy NGC 2903 in Leo is up high enough to view as well. In small scopes ngc 2903 appears as an elongated oval with a bright central core. In larger scopes small bright and dark patches may be seen within the galaxy.

Globular clusters

Brightest globular visible this time of year is Messier 79 down below Orion in constellation Lepus. In a telescope it has bright dense central core surrounded by a less dense halo of stars.

Comets

17P Holmes is in constellation Perseus east of the star Algol. It is currently around 80 or so arc minutes across. You’ll probably need binoculars and dark skies to locate it.

Look for the comet 46P/Wirtanen early in the evening in the constellation Pisces. It is magnitude 9.2 in brightness and x arc min across.

29P/Schwasmann-Wachmann is in constellation Auriga and is around magnitude 11.6. It has a very small coma, only 15 arc-secs wide so it will appear stellar in the eyepiece. You need to sketch the star field carefully or capture images separated by half hour or so in time to locate it.

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