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12/11/2015 – Ephemeris – The Geminid meteor shower will be cranking up this weekend
Ephemeris for Friday, December 11th. The Sun will rise at 8:09. It’ll be up for 8 hours and 52 minutes, setting at 5:02. The Moon is new today, and won’t be visible.
Over the weekend and through Monday night the Geminid Meteor shower will be seen. This shower is actually the bet of the year, with higher hourly counts of meteors than the more famous Perseid meteor shower of August. Around here the cold weather and the more than even chance that it will be cloudy have kept this astronomer from having seen even one. Maybe this year. The Geminids can be seen all night because the radiant point is in the northern sky, well north of the celestial equator at least. At 9 p.m. the constellation Gemini rises sideways with the namesake of the twins, the stars Castor and Pollux vertically aligned in the east with Castor on top. The closest to the peak numbers will be seen Monday early morning and Monday night.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
All Sky view one hour intervals for The Geminid meteor shower the night of December 13-14, 2015.. Note the radiant “GemR”. Created with my LookingUp program and GIMP.
Note the times are in Universal time conversion to local time.
UT EST 2 9 p.m. 3 10 p.m. 4 11 p.m. 5 12 m. 6 1 a.m. 7 2 a.m. 8 3 a.m. 9 4 a.m. 10 5 a.m. 11 6 a.m.
For locations other than EST Eastern Standard time (UT – 5 hours), just use EST as your local time. The latitude is set for near 45º north.
12/01/2015 – Ephemeris – Previewing December skies
Ephemeris for Tuesday, December 1st. The Sun will rise at 7:59. It’ll be up for 9 hours and 4 minutes, setting at 5:03. The Moon, 2 days before last quarter, will rise at 11:13 this evening.
December is the month with the shortest daylight hours. Winter will officially arrive at the winter solstice on the 21st at 11:48 p.m. There will be little movement in the sunset times: In the Traverse City/Interlochen area this will be from 5:03 tonight, down to 5:02 and then advancing to 5:11 at the end of the month. There is more movement in the sunrise times which will advance from 7:59 today to 8:20 on the 31st. There is also little movement of daylight hours. The noontime sun will hang around 22 to 23 degrees above the southern horizon all month. We have some great events this month, from an occultation of Venus by the moon on the 7th, to the Geminid meteors on the 14th and Comet Catalina will be seen in binoculars on mornings all this month.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addenda
Star Chart for December 2015. Created using my LookingUp program. Click on image to enlarge.
The planets and stars are plotted for the 15th at 9 p.m. EST. That is chart time. Note, Traverse City is located 45 minutes behind our time meridian. To duplicate the star positions on a planisphere you may have to set it to 45 minutes earlier than the current time.
Evening astronomical twilight ends at 6:48 p.m. EST on December 1st, decreasing a minute 9 days later before increasing to 6:57 p.m. EST on the 31st.
Morning astronomical twilight starts at 6:15 a.m. EST on December 1st, and increasing to 6:34 a.m. EST on the 31st.
Add a half hour to the chart time every week before the 15th and subtract and hour for every week after the 15th.
For a list of constellation names to go with the abbreviations click here.
- Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
- The Summer Triangle is still up and is shown in red.
- GemR is the Geminid meteor shower radiant
Calendar of Planetary Events
Credit: Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC)
To generate your own calendar go to http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html
Times are Eastern Daylight Time. Some additions made to aid clarity.
Date Local Event
Time EST
Dec 01 Tu Venus: 43.3° W 03 Th 2:41am Last Quarter 04 Fr 1:21am Moon-Jupiter: 2° N 04 Fr 1:33pm Moon Ascending Node 05 Sa 9:56am Moon Apogee: 404800 km 05 Sa 9:40pm Moon-Mars: 0.1° N - Occultation ** 07 Mo 11:55am Moon-Venus: 0.7° S - Occultation * 11 Fr 5:29am New Moon 12 Sa 3:15am Moon South Dec.: 18.4° S 14 Mo 12:48pm Geminid Shower: ZHR = 120 17 Th 9:32pm Saturn-Antares: 6.2° N 18 Fr 10:13am Moon Descending Node 18 Fr 10:14am First Quarter 21 Mo 3:53am Moon Perigee: 368400 km 21 Mo 11:48pm Winter Solstice 22 Tu 9:00pm Ursid Shower: ZHR = 10 23 We 9:16pm Mars-Spica: 3.5° N 23 We 2:09pm Moon-Aldebaran: 0.7° S 25 Fr 2:30am Moon North Dec.: 18.4° N 25 Fr 6:11am Full Moon 28 Mo 9:59pm Mercury Elongation: 19.7° E 29 Tu 3:30pm Moon-Regulus: 2.9° N 31 Th 12:55pm Moon-Jupiter: 1.6° N 31 Th 3:19am Moon Ascending Node Jan 01 Fr Venus: 37.9° W
* The occultation will be visible in the US, except extreme southwestern Alaska and Hawai’i; and Canada down to Panama. In the Grand Traverse area of Michigan the occultation starts around 12:20 p.m. and ends around 1:27 p.m. This is a daytime event for most of the US. Note that the actual time depends on your exact location. I’ll have more information in a non Ephemeris post on Saturday the 5th. The Occultation map is here.
** On December the 5th there will be an occultation of Mars visible across the Indian Ocean and much of Australia. That occultation map is here.
Estimating occultation timings for your location
I used Cartes du Ciel the free software that I have a link to on the right. Make sure that the program is set for topocentric positions under Setup/Solar System. And you have entered your position under Setup/Observatory. You can find your location in Google Earth, or your GPS device or smart phone.
You can also use Stellarium. Just make sure the Moon is normal sized.
In both programs you can lock the Moon or Aldebaran in the center of the screen Pick a time in advance of the occultation and using the set time window walk the star towards the Moon, mark the time. Then walk the star out from the Moon and record the reappearance time. That’s it.
This should work with other planetarium programs too.
For better accuracy go to the International Occultation Timing Association (IOTA) website. Download and install their Occult4 program for Windows computers. Follow the instructions. When I ran the program for my location, the location I use for Interlochen/Traverse City (Since I live approximately half-way between the two). I got results within a half-minute of the IOTA Occult4 program results. So the approximation method using planetarium programs is valid.
Comet C/2013 US10 (Catalina)
This comet has been hiding for the last two years after its discovery, moving into the far southern hemisphere of the sky. However this month it has emerged into our morning sky. This comet is a one time visitor from the Oort Cloud to the inner solar system and will be ejected into interstellar space. It passed perihelion on November 15th, coming just inside the Earth’s orbit on the other side of the Sun from us. It’s orbit will be headed northward and a bit toward us, so it will keep its brightness steady.
The position marks in the chart have the date and the magnitude. However the comet is currently appearing one magnitude dimmer than shown. So instead of appearing as nearly 5th magnitude, it will really be 6th magnitude. It’s definitely a binocular or telescopic object.
According to the brightness graph the comet began to under perform in brightness back in September, however, according to a new brightness formula the comet may increase in brightness by a magnitude by late February when it will be well placed for viewing all night. To monitor the brightness reports from observers go to http://www.aerith.net/comet/catalog/2013US10/2013US10.html.
The tracks of Comet C/2013 US10 (Catalina) for December 2015 along with part of Venus’ track. Created using Cartes du Ciel (Sky Charts).
12/12/2014 – Ephemeris – The Geminids will zip through again this weekend
Ephemeris for Friday, December 12th. The sun will rise at 8:10. It’ll be up for 8 hours and 52 minutes, setting at 5:02. The moon, 2 days before last quarter, will rise at 11:19 this evening.
The Geminid meteor shower will reach its peak early Sunday morning, however the bright moon , rising after midnight will interfere. The Geminids, however do have a number of really bright fireballs for which the Moon won’t matter. The good news is that the Geminids will be visible all night. You don’t have to wait until the morning hours to see them. So around midnight Saturday night will probably be the best time to see them. Also the shower has a broad peak and there may be another peak on Monday or Tuesday night and morning. The peak numbers per hour for the Geminids will be close to 120. That’s the best for any year in and year out shower. To bad it occurs in such a cloudy month.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The numbers of Geminids are already rising.
NASA’s Meteoroid Environment Office plots of fireball orbits for the night of December 10-11, 2014. The large number of yellow orbits oriented toward 2 o’clock are Geminids. Check spaceweather.com for each day’s fireball orbits. This plot includes 22 Geminid fireballs. Credit NASA via Spaceweather.com
Geminid Radiant
The Eastern sky got the Geminid meteor shower at 8 p.m. December 13, 2014. Created using Stellarium.
The Eastern sky got the Geminid meteor shower at midnight December 14, 2014. Created using Stellarium.
Remember Geminids can be seen all over the sky. It’s their streaks that can be extended back to the radiant.
12/11/2014 – Ephemeris – The Geminid meteors will reach peak numbers Saturday night to Sunday morning
Ephemeris for Thursday, December 11th. The sun will rise at 8:09. It’ll be up for 8 hours and 53 minutes, setting at 5:02. The moon, 3 days before last quarter, will rise at 10:21 this evening.
This weekend is the peak of the Geminid meteor shower. It is the best meteor shower of the year and it is getting more active over the years. The projected peak numbers is 120 meteors an hour spotted by a single observer when the radiant of the shower is overhead. It’s known as the zenithal hourly rate (ZHR). Anyway, the radiant is the point in space where the meteors seem to come from, which is near the star Castor in the constellation Gemini from which the shower gets its name. The meteors will be seen all over the sky, but they all can be traced back to the radiant. The body responsible for this meteor shower is an asteroid rather than a comet. It comes very close to the sun, so may crumble due to heat stress. I suppose I can’t resist this: That’s how the asteroid crumbles.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Geminid Radiant. From my LookingUp program.
The Eastern sky got the Geminid meteor shower at 8 p.m. December 13, 2014. Created using Stellarium.
The Eastern sky got the Geminid meteor shower at midnight December 14, 2014. Created using Stellarium.
The Stellarium charts differ from mine at top in how the constellation lines are drawn, especially Gemini. In all charts Castor is not labeled. However it is the bright star above Pollux. The meteors will will appear all over the sky, but true Geminids can be traced back near Castor. Also when the radiant is lowest in the sky, thought the numbers of meteors will be low, the brighter meteors will produce long streaks, since the will hit our atmosphere at a glancing angle.
12/08/2014 – Ephemeris – Looking forward to the Geminid meteor shower next weekend
Ephemeris for Monday, December 8th. The sun will rise at 8:06. It’ll be up for 8 hours and 55 minutes, setting at 5:02. The moon, 2 days past full, will rise at 7:28 this evening.
This upcoming weekend is the weekend of the greatest annual meteor shower of the year. They’re the Geminids. I confess to never having seen a Geminid. The reason is that it’s generally too cloudy, and for me too cold. They are now twice as active as the Perseid meteors of August with a 120 per hour peak, when the radiant point in Gemini is overhead. The body that was discovered to produce these meteors doesn’t appear to be a comet. It is designated as an asteroid 3200 Phaethon. Phaethon gets extremely close to the sun at 13 million miles (21 million km) and one of the STEREO Sun monitoring satellites caught it developing a tail when close to the Sun. Phaethon may then be the first known rock comet. I’ll have more later this week.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orbits of last year’s fireballs on the night of December 13-14 as recorded by NASA’s All Sky Cameras. The preponderance of fireballs (bright meteors) are Geminids. These are published daily on Spaceweather.com. Credit: NASA and Spaceweather.com
12/13/2013 – Ephemeris – The Geminid meteor shower will peak overnight
Ephemeris for Friday, December 13th. The sun will rise at 8:11. It’ll be up for 8 hours and 51 minutes, setting at 5:02. The moon, half way from first quarter to full, will set at 5:27 tomorrow morning.
The Geminid meteor shower will reach maximum around 12:45 a.m. tomorrow morning. The big problem will be the bright moon, so only the brightest meteors will be visible before the moon sets tomorrow morning. The 5:27 moon-set time will give the Geminids about an hour of dark skies, plus maybe another half hour of unobjectionable morning twilight to see them at their best. The Geminids will appear to originate from near the star Castor at the head of the constellation Gemini, where Jupiter is currently located. It is said that the Geminids are year in and year our the most reliable shower. That may be true, because in 1983 the source of the meteor shower was found, a long dead comet hulk, that resembles an asteroid but with a comet’s orbit.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Geminid radiant at 6 a.m. December 14, 2014 after moon set. Created using my LookingUp program for Windows
The brighter Geminids can be seen all night, but the darkest time will be just before dawn.
12/13/2012 – Ephemeris – The Geminid meteor shower reaches its peak tonight.
Ephemeris for Thursday, December 13th. The sun will rise at 8:11. It’ll be up for 8 hours and 51 minutes, setting at 5:02. The moon is new today, and won’t be visible.
Tonight will be the peak of the Geminid meteor shower. This is one of the most active showers of the year. Some say it’s even more active than the Perseid meteor shower of August with up to 100 meteors or shooting stars visible an hour. They will seem to come from near the star Castor in the constellation Gemini which is rising high towards midnight. The moon will not interfere because it’s new. The radiant point is highest at 2 a.m. But will be in the sky from 8 p.m. on All you’ll need then is clear skies. If it does clear up, make sure you dress warmly. It will take up to 10 minutes or even more for your eyes to get accustomed to the darkness to be able to see the meteors. The meteors are related to a body called Phaethon, a dead comet nucleus.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Geminid Radiant
12/30/11 – Ephemeris – The best 2012 astronomical events
Friday, December 30th. The sun will rise at 8:19. It’ll be up for 8 hours and 51 minutes, setting at 5:10. The moon, 2 days before first quarter, will set at 12:02 tomorrow morning.
Let’s look ahead at next year’s astronomical events for this last Ephemeris of 2011. What won’t happen will be the end of the world on December 21st. There is no planet Nibiru. The closest alignment of the sun at the winter solstice and the center of the galaxy was in 1997. What will happen is partial eclipse of the sun, or about a half hour of it, before sunset on May 20th. An extremely rare transit of Venus, that is the planet Venus will cross the face of the sun on June 5th for us. We’ll see about 3 hours of it before sunset that day. The sun will continue to be more active next year with more sunspots and more displays of the northern lights. It will also be a good year for the Perseid meteor shower of August and the Geminids of December.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
Bob Moler's Ephemeris Blog 