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10/08/2013 – Ephemeris – Comet ISON spotted from Mars
Ephemeris for Tuesday, October 8th. The sun will rise at 7:49. It’ll be up for 11 hours and 20 minutes, setting at 7:09. The moon, 3 days before first quarter, will set at 9:36 this evening.
Tonight look in the southwest at 8 p.m. or so to see the crescent moon to the upper left of Venus. In other news last week Sunday the Mars Reconnaissance Orbiter took photographs of Comet ISON. These have been posted on the Internet. Google ISON Mars. The Satellite’s HiRISE camera wasn’t built for the task, and only revealed a faint blob of light. Earth bound amateur astronomers can do a lot better. The images are posted on the University of Arizona’s web site and are not affected by government shutdown. Any images of the comet from the Curiosity rover will have to wait until the shutdown is over to be posted. Operators of the Opportunity and Curiosity rovers are still at work since ongoing space operations are deemed essential.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
HiRISE images of Comet ISON on Sept. 29, 2013. Credit: NASA/JPL/University of Arizona.
10/02/2013 – Ephemeris – Where are the bright planets and one dim comet?
Ephemeris for Wednesday, October 2nd. The sun will rise at 7:41. It’ll be up for 11 hours and 38 minutes, setting at 7:20. The moon, 2 days before new, will rise at 6:14 tomorrow morning.
Time again to check out the bright planets. Saturn and Venus will be at the same height above the west southwestern horizon. Dimmer Saturn will be to the right of Venus by one and a half widths of a fist held at arm’s length. Binoculars may be needed to Saturn. Saturn will set at 8:40, while Venus will set at 8:56 p.m.. We are losing Saturn in the sun’s glare for a few months. The rest of the planetary action will be in the morning sky. The giant planet Jupiter will rise at 12:36 a.m. in the east northeast. It’s cruising against the stars of Gemini this viewing season. By 6 a.m it will be high in the southeast, the brightest object in that direction. Mars will rise at 3:30 a.m. also in the east northeast. It’s in the east at 6 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus and Saturn low on the west southwestern horizon along with Saturn at 8:15 p.m. on October 2, 2013. Created using Stellarium.
I was out at the Lanphier Observatory of the Leelanau School in Glen Arbor Michigan Monday evening about this time, to show Venus to the audience for Andrea Wulf’s talk about some of her book Chasing Venus. If the book is like her talk, it should be fabulous. It’s about the 18th century expeditions of many nation to view a pair of transits of Venus in order to determine the size of the solar system. Anyway the sky was like this with Venus setting over the low Sleeping Bear Dunes across Sleeping Bear Bay.
Jupiter, Mars with the winter stars and constellations at 6 a.m. on October 3, 2012. Created using Stellarium.
The tracks of Mars and Comet ISON at 6 a.m. from October 3 to 9, 2013. The comet may still be too faint to view in binoculars. Chart created using Cartes duCiel.
The yellow line is the ecliptic. The blue line is the constellations lines for Leo. Comet ISON positions are blue dots. It’s too far away for the software to show a tail.
Links to other sites for Comet ISON information as it approaches perihelion
C/2012 S1 (ISON) is the official designation for Comet ISON, which will pass close to Mars on its inbound leg of its orbit of the sun.
Universe Today has two links on what to expect as Comet ISON nears the sun.
The Comet ISON, a Viewing Guide From Now to Perihelion: http://www.universetoday.com/104818/comet-ison-a-viewing-guide-from-now-to-perihelion/
The comet’s coma (head) is turning green as it approaches. That’s a good thing: http://www.universetoday.com/105087/comet-ison-goes-green/
Here’s another site: The NASA Comet ISON Observing Campaign: http://www.isoncampaign.org/ which answers some of your questions and details some of the world-wide and solar system wide attempts to observe Comet ISON as it makes its mad dash to and from the sun.
As Comet ISON approaches the Sun it is doing so close to the ecliptic plane (plane of the earth’s orbit). Situated in the morning sky, it will follow fairly close to the ecliptic, passing Mars and Saturn on the way in from our point of view. It will physically pass close to Mars this week. Expect photos of the comet from Mars by the end of the week. What Martians are taking the photos? Why we are. NASA and the Europeans have assets on and around Mars who will, in their robotic way photograph and possibly analyze the comet as it passes by. The apparent passage by Saturn is apparent from our point of view from the earth. It is far in the background. Comet Encke, the shortest of the periodic comets with a 3.3 year orbit will be in some of the photographs from earth.
Around the end of October Comet ISON will cross the earth’s orbit heading to perihelion on November 28th. Comet will stay a morning comet after leaving the sun heading northward from the earth’s point of view. We expect the comet be at its brightest, but rapidly fade in December. But who knows. I will be reporting what I know and see about the time the comet becomes visible in binoculars or a small telescope. Stay tuned.
08/19/2013 – Ephemeris – Comet ISON, final approach!
Ephemeris for Monday, August 19th. The sun rises at 6:50. It’ll be up for 13 hours and 51 minutes, setting at 8:41. The moon, 1 day before full, will set at 6:22 tomorrow morning.
Comet ISON is beginning to become visible from the earth after spending a few month’s behind the sun. It has shown earlier this year that it had not been brightening as predicted, but soon will be visible for better measurements. Tomorrow it the Mars Reconnaissance Orbiter will take its first image of ISON. The Curiosity and Opportunity rovers will also soon take photo’s of Comet ISON in the martian sky. When ISON becomes visible from Mercury, the MESSENGER spacecraft orbiting Mercury will get its chance. All available instruments on earth and deployed in the solar system will track the comet to see how it evolves and to see if it will survive its brush with the sun’s corona to become a bright autumn comet.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Hubble Space Telescope image of Comet ISON against a field of distant galaxies, April 30, 2013. Credit NASA.
12/31/2012 – Ephemeris – Looking at the prospective comets of 2013
Ephemeris for New Years Eve, Monday, December 31st. The sun will rise at 8:19. It’ll be up for 8 hours and 53 minutes, setting at 5:12. The moon, 3 days past full, will rise at 8:51 this evening.
As we enter a new year tonight, let\s look ahead at what we expect to see in the skies in 2013. The big events next year will be two comets that could be quite bright. Mid-March will bring Comet PanSTARRS to the evening sky. This is a first time comet for astronomers, so its behavior may be unpredictable, but it is currently sticking to brightness projections and may be as bright as the brightest stars at its brightest. The second comet is Comet ISON. This will fly close to the sun on November 28th. It could disintegrate, its nucleus could split into multiple pieces, or it could survive intact. The last two scenarios will give us a bright morning comet in early December. So may we have a happy comet new year.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Here are two links to the website of Seiichi Yoshida for each of the comets. Most revealing at this point are the magnitudes graphs showing the actual brightness measurements as black dots with the predicted magnitudes as an orange line, The vertical line is the perihelion date, the date the comet is closest to the sun. Comet ISON has a second magnitude graph for when the comet is closest the sun and may become bright enough to be seen in the daytime.
Magnitudes are like golf scores, the lower the number the better, or in this case brighter the comet is. the Faintest star visible to the naked eye is 6th magnitude. Jupiter is usually around -2, Venus -4, and the sun -26. As you can see from the scatter of the actual brightness estimates, pinning down the brightness of a fuzzy comet is rather difficult. Comets generally appear dimmer than their magnitudes would suggest.
Here are the ;inks:
11/02/2012 – Ephemeris – Astronomy tonight!
Ephemeris for Friday, November 2nd. The sun will rise at 8:22. It’ll be up for 10 hours and 7 minutes, setting at 6:29. The moon, half way from full to last quarter, will rise at 9:10 this evening.
Previewing the comets of 2013 will be the topic at the Grand Traverse Astronomical Society’s monthly meeting at 8 p.m. at Northwestern Michigan College’s Rogers Observatory. The program will be given by yours truly. Next year we may be treated by the possibility of two bright comets: PanSTARRS and ISON The questions isn’t will they arrive, they will; but how bright will they be. ISON in particular, could be spectacular. Starting at 9 p.m. will be the monthly viewing night at the observatory. On tap if its clear will be the galaxies of fall along with Jupiter and the moon rising. The Observatory is located south of Traverse City on Birmley Road off either Garfield or Keystone roads.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
10/02/2012 – Ephemeris – Two bright comets next year, maybe?
Ephemeris for Tuesday, October 2nd. The sun will rise at 7:42. It’ll be up for 11 hours and 38 minutes, setting at 7:20. The moon, 3 days past full, will rise at 8:23 this evening.
It looks like we’ll have possibly two comets to grace our skies next year. These are first time comets and there is trouble with predicting their brightness. We can make a guess when we see them far from the sun, but that doesn’t always pan out. The first comet to be seen will be Comet 201l L4, named PANSTARRS. It will reach its closest to the sun on April 17th. It was discovered with the Pan-STARRS telescope in Haleakala, Hawaii. It could optimistically be as bright as the star Vega. The second was Comet 2012 S1 ISON (I hope that’s how it’s pronounced) discovered on September 21st, 10 days ago. This comet has the added problem. On November 29th, 2013 it will pass a million miles from the center of the sun, and may not survive.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Here’s some information on these comets from Gary Kronk’s Cometography: http://cometography.com/current_comets.html
Bob Moler's Ephemeris Blog 