12/23/11 – Ephemeris – This year’s Christmas stars
Friday, December 23rd. The sun will rise at 8:17. It’ll be up for 8 hours and 48 minutes, setting at 5:06. The moon, 1 day before new, will rise at 8:04 tomorrow morning.
We have two bright planets and the brightest nighttime star out to be our Christmas stars this year. The planet Venus appears in the southwest in the evening and in seen higher and higher each evening, leading the sun in its slow climb as we move through winter into spring. Jupiter holds forth high in the south, the brightest star-like object once Venus sets. The brightest of all the night-time stars is Sirius, whose name means “Dazzling One” rising higher in the southeast, whiter than any planet with a tinge of blue, especially when seen in binoculars or a telescope.. It is accompanied by the rest of the bright stars of winter, including those of the great constellation Orion the hunter, whose three stars of his belt point down and to the left at Sirius.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
12/22/11 – Ephemeris – Winter is here!
Thursday, December 22nd. The sun will rise at 8:16. It’ll be up for 8 hours and 48 minutes, setting at 5:05. The moon, 2 days before new, will rise at 7:06 tomorrow morning.
At 12:30 this morning the sun reached its farthest southerly travel and is now slowly beginning to turn northward again. That point was the winter solstice, or to be more general the December solstice, because in the southern hemisphere of the earth summer has arrived, while we star winter. December 21st is the usual day of the solstice, and it will be again next year because next year is the leap year and will set the calendar back to match the seasons. The adding of the extra day every 4 years came under the auspices of Julius Caesar and gave us the Julian calendar. It slightly over corrected the calendar. The latest adjustment was the Gregorian reform that will fix the calendar for the next few millennia.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
12/21/11 – Ephemeris – Where are the bright planets this week?
Wednesday, December 21st. The sun will rise at 8:16. It’ll be up for 8 hours and 48 minutes, setting at 5:04. The moon, 3 days before new, will rise at 5:58 tomorrow morning.
It’s Wednesday and time again to take a look at the whereabouts of the bright planets. The planet Venus is prominent in the southwestern twilit sky after sunset setting at 7:30. Jupiter is now the most prominent planet of the evening sky located in the high in the south and is seen against the stars of the constellation Aries. It will pass due south at 8:36 p.m. It will set at 3:20 a.m.. Mars will rise at 11:25 p.m in the east northeast and will be in the constellation Leo. Mars will be due south at 6:01 a.m. It is 105 million miles away and closing. Saturn will rise at 2:57 a.m. just to the left of the bright star Spica in the east southeast. Winter starts at 12:30 tomorrow morning. I’ll have more on that tomorrow.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
12/20/11 – Ephemeris – Procyon, the “Little Dog Star”
Tuesday, December 20th. The sun will rise at 8:15. It’ll be up for 8 hours and 48 minutes, setting at 5:04. The moon, 3 days past last quarter, will rise at 4:45 tomorrow morning.
Visible low in the east at 9 p.m. appears the star Procyon to its lower left is Sirius the brightest night time star. Procyon is the bright star in the constellation Canis Minor, or lesser dog. I can find only one other star in Canis Minor. Perhaps it’s a hot dog. If Sirius, in Canis major is the Dog Star then Procyon should be the Little Dog Star. However Procyon is an interesting name. It means “Before the dog”, which is an allusion to the fact that Procyon, though east of Sirius actually rises before it. This is due to Procyon’s more northerly position. This effect doesn’t work south of the equator, however. Procyon is a star much like Sirius but farther away. [It’s 11.41 to Sirius’ 8.6 light years away. And like Sirius it even has a small white dwarf star in its system.]
* Times, as always are for the Traverse City/Interlochen area of Michigan. Text in brackets was omitted in the audio program due to time constraints.
Addendum
Procyon, Sirius and the stars of winter. Created using Stellarium
The grid lines are right ascension and declination, analogous to longitude and latitude on the earth. Looking eastward the right ascension lined run from the upper left to the lower right. Thus Procyon is definitely farther east than Sirius.
12/19/11 – Ephemeris – Comet Lovejoy survives!
Monday, December 19th. The sun will rise at 8:14. It’ll be up for 8 hours and 49 minutes, setting at 5:04. The moon, 2 days past last quarter, will rise at 3:29 tomorrow morning.
Comet Lovejoy surprised most astronomers by surviving its encounter with the sun last Thursday evening. By Friday morning it was receding from the sun minus its tail. The tail it had approaching the sun was still there, but what emerged looked like a really bright star. It fooled me until I saw the animated images that showed the comet disappearing around the left side of the sun and a bright star-like object emerge on the right. As Friday wore on comet Lovejoy began to grow a new tail. Over the weekend images came in from all the six solar monitoring satellites. All had recorded the comet, and some as the comet came very close to the sun to see the interaction of the comet’s tail with the sun’s corona. The comet has since been picked up from the ground.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
Addendum
The comet has been photographed by a Las Vegas astronomer in the morning before sunrise!
For more information go to www.spaceweather.com. Checkout the archive pages too!
Here is a US Navy site following Comet Lovejoy: http://sungrazer.nrl.navy.mil/index.php?p=news/birthday_comet
For Scott: I haven’t seen a good magnitude on it yet. It’s going to be a southern hemisphere object.
Here’s a link to the Elements and Ephemeris of the comet from the Minor Planet Center: http://scully.cfa.harvard.edu/cgi-bin/returnprepeph.cgi?d=c&o=CK11W030
Comet Lovejoy is growing a new tail
Wow! It looks like C/2011W3 Lovejoy is growing two new tails, a faint ion tail and a brighter dust tail.
Comet Lovejoy growing new tails. Courtesy ESA, NASA, LASCO C3 group.
The old tail is still visible.
Lovejoy Lives!
Barely.
The Solar Dynamics Observer (SDO) detected Comet Lovejoy (C/2011W3) leaving the sun, but thousands of times fainter than it went in. the LASCO C3 and C2 images that I’ve seen for 9:30 UT show the ghost of Lovejoy’s tail. See Below:
Ghost of Comet Not So Past
Sorry, couldn’t help it. It’s the season I guess. However reports of Lovejoy’s death may have been exaggerated. Sorry Mr. Twain.
Update 8:38 a.m.
I dashed off the above as soon as I got up this morning. It wasn’t until later looking at spaceweather.com’s animation of the LASCO C3 images that I found that the over bright star to the lower left of the sun was what’s left of Comet Lovejoy. I took a quick look at Stellarium and saw no planets in that position, so I thought it may have been an artifact. So it appears Lovejoy lost all its volatile components and is probably a bare nucleus like the progenitor of the Geminid meteor shower 3200 Phaethon. I wonder if the brightness of it will change its size estimates?
Ghost tail of Comet Lovejoy. Courtesy of ESO, NASA and the LASCO team.
12/16/11 – Ephemeris – The constellation Orion rising
Friday, December 16th. The sun will rise at 8:12. It’ll be up for 8 hours and 50 minutes, setting at 5:03. The moon, 1 day before last quarter, will rise at 11:49 this evening.
At 9 p.m. the constellation of Orion the giant hunter will be rising in the east southeast, with its belt stars nearly vertically aligned. The belt stars are contained within a tilted rectangle of four bright stars that’s leaning to the left. The brightest of the top stars is Betelgeuse a bright red star. It’s a huge red giant star. Both top stars are Orion’s shoulders. The other shoulder star is Bellatrix. The bottom stars are Orion’s knees. The brightest, diagonally opposite from Betelgeuse is Rigel, a bright blue-white giant star. The other knee star is named Saiph. Orion is home to a beautiful nebula or cloud of gas, which we’ll explore later this winter, visible in binoculars it is located right and below Orion’s belt stars.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
Addendum
Orion with star names
12/15/11 – Ephemeris – Comet Lovejoy will skim past the sun today
Thursday, December 15th. The sun will rise at 8:12. It’ll be up for 8 hours and 50 minutes, setting at 5:02. The moon, 2 days before last quarter, will rise at 10:39 this evening.
Today Comet Lovejoy will pass 100,000 miles above the surface of the sun. The sun is 865,000 miles in diameter, so that’s very close. Will the comet survive? Will it break into multiple pieces? Or will it evaporate in the sun’s intense heat? To get the latest news on the internet go to Spaceweather,com or space.com. For first hand information google SOHO NASA. Look for real time images. LASCO C3 and C2 are the views you want. These are near white light views with the sun’s face blocked out so the solar corona is visible. The C2 view is closer in than the C3 view. The comet will move from the lower left to upper right. And will go behind the occulting disk that hides the sun. The comet’s tail should be quite long.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
Update 6:09 a.m.
Comet Lovejoy at 9:30 UT or 2:23 a.m. EST. Courtesy of ESA, NASA, LASCO Team.
Click image to enlarge.
Planetary Society Blog has animation of Comet Lovejoy (C/2011W3) entering SOHO’s LASCO C3 field.
Emily Lakdawalla has the scoop. http://www.planetary.org/blog/article/00003301/
The comet should be closest to the sun (100,000 miles from the surface) tomorrow about 7 p.m. EST (0h U.T. December 16th). Supposedly about 600 feet in diameter. Do you think it’s got a snowball’s chance in hell of surviving? The sun’s surface (photosphere) is about 10,000 degrees F.
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Bob Moler
