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03/14/2013 – Ephemeris – Comet PanSTARRS is hard to pick out of the twilight
Ephemeris for Pi Day 3/14, Thursday, March 14th. The sun will rise at 7:56. It’ll be up for 11 hours and 51 minutes, setting at 7:47. The moon, 3 days past new, will set at 11:13 this evening.
Comet PanSTARRS is moving northward and is seen higher in the west at 45 minutes after sunset. That’s 8:32 p.m. here in the Interlochen/Traverse City area. At that time it will be about 7 ½ degrees above the horizon. That’s three and a half knuckles up on a fist held at arms length above the horizon. Spaceweather.com has the latest photos of the comet with the advice that a several second exposure with a digital camera shows the comet better than to the eye. My finder charts which are close to photo realistic are on bobmoler.wordpress.com. Our weather isn’t the best here with rain fog and snow. But hope springs eternal. The comet will be around for the rest of the month but will still be fighting twilight and a brightening moon.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Comet PanSTARRS from March 14, 2013 through the 17th. Created using Stellarium and Cartes du Ciel.
Now that the moon can’t be used as a pointer to the comet, I chosen to show the comet’s positions through the weekend.
03/13/2013 – Ephemeris – Comet PanSTARRS and two bright planets
Ephemeris for Wednesday, March 13th. The sun will rise at 7:58. It’ll be up for 11 hours and 48 minutes, setting at 7:46. The moon, 2 days past new, will set at 10:10 this evening.
It’s time to check out a comet and the two remaining bright planets for this week. Comet PanSTARRS is in the west, moving away from the sun, and not getting that much higher in the west as it moves northward rather than eastward. The comet will set at 9:11. The tail may still be visible after the head sets. Jupiter is located in the constellation of Taurus and is in the high southwest during the evening. It will set at 2:19 a.m. Jupiter is a wonderful sight in telescopes with its cloud bands and its moons which change positions each night. The other bright planet Saturn will rise at 11:42 p.m. in the east southeast. It’s located in eastern Virgo. Saturn will pass due south at 4:52 a.m. Saturn is the most beautiful of planets.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Comet PanSTARRS and the moon at 45 minutes after sunset on March 13, 2013. Created using Stellarium, Cartes du Ciel and my LookingUp program.
See yesterdays post on how the image was created. The moon’s size annd the comet’s brightness are exaggerated a bit.
Jupiter and the winter constellations tip to the southwest at 10 p.m. on March 13, 2013. Created using Stellarium. Click on the image to enlarge.
Saturn with a preview of the summer constellations seen at 6 a.m. on March 14, 2013. Created using Stellarium. Click on the image to enlarge.
08/12/2013 – Ephemeris – Comet PanSTARRS will appear near the moon tonight
Ephemeris for Tuesday, March 12th. The sun will rise at 7:59. It’ll be up for 11 hours and 45 minutes, setting at 7:45. The moon, 1 day past new, will set at 9:05 this evening.
Tonight 40 to 45 minutes after sunset, that’s about 8:30 p.m., if it’s very clear down to the western horizon Comet PanSTARRS might be glimpsed low on the western horizon. The day old sliver of the moon will point to the comet. The comet will appear just to the left of the moon by about 8 moon widths. The comet will appear due west, so a compass will help locate it. It’s tail is expected to be nearly vertical and canted to the left. If the comet is bright enough the tail will appear to be split in two. The gas component is ionized and is pushed back rapidly by the solar wind. Cometary dust is pushed by the pressure of sunlight. Near perihelion, its closest to the sun as comet is moving crosswise to its tail. The tail will swing to the right in the coming days.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Comet PanSTARRS with the moon at 8:30 p.m. or 45 minutes after sunset) on March 12, 2013. Created using Stellarium, Cartes du Ciel and my Looking Up.
As noted in yesterday the sky is from, Stellarium and the comet from Cartes du Ciel. Both free programs that can be downloaded from links on this page. The moon is from my own, much simpler LookingUp program. The moon does appear slightly larger and brighter than how it will appear in the sky, as does the comet. The comet will set shortly after 9 p.m. and the tail may be visible for a while after that.
Reports show that the comet is reaching 1st magnitude, but not for long. Check the link for spaceweather.com for some cool pictures of the comet in the evening twilight.
03/11/2013 – Ephemeris – Comet PanSTARRS enters the northern sky
Ephemeris for Monday, March 11th. The sun will rise at 8:01. It’ll be up for 11 hours and 42 minutes, setting at 7:43. The moon is new today, and won’t be visible.
Comet PanSTARRS is now officially in our skies. It may be visible very low on the western horizon about 45 minutes after sunset. That will make it about 8:30 p.m. The head of the comet may make it to second magnitude, about as bright as a Big Dipper star. The tail should point nearly straight up. As the days go by the tail will lean to the right and the comet moves northward. Tomorrow night the comet will be just left of the thin crescent moon. Pictures of the comet can be found at spaceweather.com, from earlier this month. PanSTARRS or Comet 2011 L4, as its official designation goes will probably not return. It came in reasonably near the plane of the solar system, but is leaving far to the north. Binoculars are the tool best used to spot it.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Comet PanSTARRS as it might appear above the western horizon at 45 minutes after sunset on March 11, 2013. Created using Stellarium and Cartes du Ciel.
Note that the comet will most likely not appear this bright. At this time the comet is only 4 degrees above the horizon. That’s less that half the width of a fist held at arms length above the horizon. The comet will set in less than a half hour after that.
The reason for using images from Stellarium and Cartes du Ciel is that Stellarium does not show comet tails, and Cartes du Ciel does not try to show a realistic twilight.
03/08/2013 – Ephemeris – Next week: Comet PanSTARRS enters our skies
Ephemeris for Friday, March 8th. The sun will rise at 7:07. It’ll be up for 11 hours and 32 minutes, setting at 6:39. The moon, 3 days before new, will rise at 5:33 tomorrow morning.
Next week it will be darker in the morning and lighter in the evening as daylight time falls upon the land. But the big attraction next week will be the appearance of Comet PanSTARRS into our northern skies. This comet was discovered by an observatory with that acronym at the summit of the Haleakala on Maui, Hawaii. Tomorrow the comet will come as close to the sun as Mercury does before heading out to deep space again. It’s distance from us will always be farther than the sun. Monday night will be our first time to spot it low in the west 45 minutes after sunset. Tuesday its will appear just to the left of the thin crescent moon. PanSTARRS is not as bright as originally predicted, so it will be difficult to spot in twilight. Binoculars are the best bet for spotting it.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Comet PanSTARRS path in the March evening sky. Created using Cartes duCiel.
Taken and updated from my article in the GTAS newsletter the Stellar Sentinel:
Comet 2011 L4 (PanSTARRS) will be entering our evening sky this month after passing perihelion on March 10th.. Here is my reporting of its discovery in the November 2012 issue:
Obviously PanSTARRS isn’t a person’s name but the first telescope of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) located on the summit of the Haleakala volcano on Maui, Hawaii. There are several Comet PanSTARRS so if you use Google or any other search engine to get more information don’t be confused. This one is C/2011 L4. Comet PanSTARRS was discovered on June 6, 2011.
We were hoping for a comet that would reach magnitude 0, as bright as the brightest stars. It seems that this is not going to be the case. The current track of the comet brightness appears to be about a magnitude dimmer than what was previously predicted. To follow PanSTARRS magnitude track, go to the web page http://www.aerith.net/comet/catalog/2011L4/2011L4.html.
The dimness of the comet will make it difficult to spot in the fading twilight. The position of the comet and the moon on the 12th. is seen above, at an hour after sunset. The sliver of the 30 hour old moon will itself be hard to spot. day by day the comet will slowly move higher in the sky and away from evening twilight, On April 1st the comet will begin to pass the Great Andromeda Galaxy.
In photographs displayed on spaceweather.com as I put this issue to bed, the comet appears to have a short tail, divided into a narrow bluish ion tail and a wide dust tail.
Next week I’ll diagram the comet for each of the evenings.
Bob Moler's Ephemeris Blog 