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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).
11/17/2015 – Ephemeris – The Leonid peak is expected to be today and tonight
Ephemeris for Tuesday, November 17th. The Sun will rise at 7:42. It’ll be up for 9 hours and 30 minutes, setting at 5:12. The Moon, 2 days before first quarter, will set at 10:49 this evening.
The Leonid meteor shower is predicted to reach its peak or rather peaks today. One this afternoon is a newly computed peak, which we obviously cannot see, and another around 11 p.m. which occurs just before the radiant rises. The radiant is the point in the sky from which the meteors seem to come from, so to see any meteors that source point must be above the horizon. The Leonid meteors are the debris of Comet 55P/Tempel-Tuttle, which was discovered independently by Ernst Tempel in 1865 and Horace Tuttle 18 days later. The 55P in the name means that it was the 55th recognized periodic comet. It has a period of 33.24 years giving rise to meteor storms every 33 years or so. This isn’t one of those years.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
An all sky chart for 5 a.m for the Leonid meteor shower for 2015. Created by my LookingUp program. The yellow pattern marked LeoR is the Leonid radiant.
The orbit of 55P/Tempel-Tuttle near the Earth. The color or the orbit is lighter north of the Earth’s orbital plane. Note that the orbit of the comet crosses the Earth’s orbital plane as it passes just inside the Earth’s orbit. Created with JPL Small-Body Database Browser.
The entire orbit of 55P/Tempel-Tuttle. The color or the orbit is lighter north of the Earth’s orbital plane. Created with JPL Small-Body Database Browser.
11/16/2015 – Ephemeris – The Leonid meteors are expected to reach their peak tomorrow
Ephemeris for Monday, November 16th. The Sun will rise at 7:40. It’ll be up for 9 hours and 33 minutes, setting at 5:13. The Moon, 3 days before first quarter, will set at 9:45 this evening.
Tomorrow night is the expected peak of the Leonid meteor shower. The expected peak will be at 11 p.m. (4 hr UT November 18). Problem is that the radiant won’t rise until just after midnight for northern Michigan. For the best visible numbers the peak of the meteor shower should coincide with the time the radiant is highest in the sky. For the Leonids, that’s when morning twilight starts. There’s another possible peak for those in Asia at 21 hr UT November 17. It’s afternoon for us. The Leonids generally produce their meteor storms of thousands of meteors an hour about every 33 years, when the comet is back near the Earth and the Sun. That next time would be around the year 2031 give or take a year. I personally missed the meteor storm of 1966 by a couple of hours. I missed the one in the late 90s by more than that. The next around 2031 may be a bridge too far for me.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The 1933 Leonid meteor storm depicted over Niagara Falls in this woodcut. Public Domain. by A Pickering.
The 1997 Leonid meteor shower as seen from orbit. Credit NASA.
Leonid meteor radiant
11/13/2015 – Ephemeris – The Leonid meteor shower will reach peak next week
Ephemeris for Friday, November 13th. The Sun will rise at 7:36. It’ll be up for 9 hours and 40 minutes, setting at 5:16. The Moon, 2 days past new, will set at 7:02 this evening.
I’m talking about meteors a lot this week. Well this is about next week’s peak of the Leonid meteor shower. The Leonid meteor shower has spectacular peaks about every 33 years when the responsible litter bug, er… comet is near us and the Sun. The last time the comet names 55P/Tempel-Tuttle passed perihelion, its closest to the Sun was 1998. We are about half way between that and the next perihelion in 2031, so we’d expect it to be a dull year with 15 meteors an hour expected tops, but either the Leonids are getting more unpredictable, or astronomers, both professional and amateur are paying better attention. The main peak is expected Tuesday night around 11 p.m. (4 hr UT Wednesday, November 18), with another peak prior to that in the afternoon (21 hr UT Tuesday, November 17). The radiant, however, will rise just before midnight in northern Michigan. The timing will be better for Europe
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Leonid meteor radiant
11/12/2015 – Ephemeris – The North Taurid meteor shower
Ephemeris for Thursday, November 12th. The Sun will rise at 7:35. It’ll be up for 9 hours and 42 minutes, setting at 5:18. The Moon, 1 day past new, will set at 6:19 this evening.
Today is the expected peak of the Northern Taurid meteor shower. While poor in numbers, the two Taurid showers produce many fireballs, that are really, really bright. So bright they are not hindered by a bright moon. They will be visible all night because the radiant, near the head of Taurus the bull will rise in the east by the end of twilight. The radiant is below the Pleiades star cluster and just above the letter V group of stars that is the head of the bull. The path of Encke’s comet, which is responsible, crosses near the Earth’s orbit twice a year. Now and where the Earth is on June 30th. Those meteors then would seem to come from out of the Sun, leaving some to speculate that the Tunguska event in 1908 was caused by a piece of Encke’s Comet.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Taurid Radiant
It turns out that Earth isn’t the only planet to have a meteor shower from Encke’s Comet. It happens to be Mercury. Dave Dickinson has a post on Universe Today pointing to an announcement of data returned from the MESSENGER spacecraft that orbited Mercury at the Division of Planetary Sciences of the American Astronomical Society (#DPS15) meeting this week.
11/10/2015 – Ephemeris – Twin meteor showers ongoing now
Ephemeris for Tuesday, November 10th. The Sun will rise at 7:32. It’ll be up for 9 hours and 47 minutes, setting at 5:20. The Moon, 1 day before new, will rise at 7:14 tomorrow morning.
Now through Thursday the North and South Taurid meteors will be most active. The North radiant, the point from which the meteors, or “shooting stars” will seem to come from, is just above the letter V star cluster that’s the head of Taurus the bull in the east in the early evening. The southern radiant is just below the V. Interestingly enough they belong to the same comet: Encke’s Comet. It has the shortest period on any known comet. Only 3.3 years. I’ll have more to say about Encke’s Comet on Thursday when I talk about the peak of the Northern Taurids that day. Today is the peak of the Southern Taurids. Both have expected peaks of only 5 meteors an hour. However both showers have a great number of fireballs.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Tracks of how the North (NTA) and South (STA) Taurid radiants move in the sky with time. Credit International Meteor Organization 2015 Meteor Shower Calendar.
10/20/2015 – Ephemeris – Halley’s Comet returns… in bits and pieces
Ephemeris for Tuesday, October 20th. The Sun will rise at 8:04. It’ll be up for 10 hours and 45 minutes, setting at 6:50. The Moon, at first quarter today, will set at 12:53 tomorrow morning.
Halley’s Comet is back! Well sorta. In the form of the Orionid meteor shower. Bits of Halley’s Comet from previous passes by the Earth’s orbit make their twice yearly show in our skies as these bits collide with the Earth’s atmosphere. Halley’s orbit passes close to the earth’s orbit at points where the Earth is around May 6th and again near October 21st. Light dust get blown back into the tail of the comet. Heavier particles, still affected by the pressure of sunlight and the gravitational pull of the Sun and planets end up roughly following the comet’s orbit. Tonight night after the Moon sets should be the best time to see them. They will seem to come from a spot above Orion and below Gemini.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orionid Radiant
We get two meteor showers from Halley’s Comet. The Orionids, when Halley is approaching the inner solar system, and the Eta Aquariids when it’s leaving. Credit my LookingUp program.
10/08/2015 – Ephemeris – The Draconid meteors will reach peak overnight tonight
Ephemeris for Thursday, October 8th. The Sun will rise at 7:49. It’ll be up for 11 hours and 21 minutes, setting at 7:10. The Moon, half way from last quarter to new, will rise at 4:33 tomorrow morning.
For this and the next few morning the Moon will pass the morning planets. This morning it’s Venus, tomorrow it will be near Mars and Jupiter, and Sunday morning it will be near Mercury.
This evening is the expected peak of the Draconid meteor shower. We can expect anything between zero and hundreds of meteors an hour. The calculated time of the peak number will be around 1:40 a.m. (5:40 UT, October 9). The point in space they will appear to come from is the head of the constellation Draco the dragon, a bit north of the bright star Vega, high in the west in the evening. Meteor experts don’t expect much from the shower this year, but the Draconids are capricious, you never know what to expect. However we do expect them to be slow-moving.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The entire sky dome including the Draconid Radiant (DraR) for 9 p.m. October 8, 2015 (1:00 UT 10/9). Created with my LookingUp program.
The entire sky dome including the Draconid Radiant (DraR) for 1:40 a.m. October 9, 2015 (05:40 UT). Created with my LookingUp program.
Morning planet animation for 7 a.m. October 8 to 11, 2015. Click on image to enlarge. Note the Moon’s size is tripled for visibility. Created using Stellarium 0.13 and GIMP.
08/12/2015 – Ephemeris – One ringed planet and a sky full of meteors
Ephemeris for Wednesday, August 12th. The Sun rises at 6:41. It’ll be up for 14 hours and 12 minutes, setting at 8:53. The Moon, 2 days before new, will rise at 5:49 tomorrow morning.
Lets take a look for the bright planets for this week. Our brightest evening planets Venus and Jupiter are leaving the evening sky in the west. Venus is 3 days from inferior conjunction with the Sun. Saturn is in the south-southwest in the evening twilight. It can be spotted just to the right of the constellation of Scorpius the scorpion and its bright red star Antares below and right of it. Even small telescopes can see Saturn’s rings. The Perseid meteor shower will reach its peak overnight tonight. Your back yard is a fine spot to view the meteors, or for dark skies, I’ll be leading an all night meteor watch at the Sleeping Bear Dunes National Lakeshore’s Dune Climb if it’s clear. I’ll be there by 9 p.m. and it will be dark enough by 10:30.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Saturn and the summer Zodiacal constellations in the south at 10 p.m. August 12, 2015. Created using Stellarium.
Saturn through a telescope at 10 p.m. on August 12, 2015. Created using Stellarium.
Next week Wednesday we will also turn to the morning sky looking for Mars and awaiting Venus’ grand entrance into the dawn skies.
All-sky meteor charts from yesterday’s post
“PerR” is the Perseid radiant.
11 p.m. August 12, 2015. Created using Bob Moler’s LookingUp program for Windows.
2 a.m. August 13, 2015. Previewing autumn stars. Created using Bob Moler’s LookingUp program for Windows.
5 a.m. August 13, 2015. Good morning Orion! Created using Bob Moler’s LookingUp program for Windows.
08/10/2015 -Ephemeris – The Tears of St. Lawrence
Ephemeris for Monday, August 10th. The Sun rises at 6:39. It’ll be up for 14 hours and 17 minutes, setting at 8:56. The Moon, half way from last quarter to new, will rise at 3:55 tomorrow morning.
Today is the Catholic Church’s feast of Saint Lawrence a deacon, who was martyred around 258. I make reference to this because of the Perseid meteor shower which will reach peak early Thursday morning. It is also known as the Tears of St Lawrence or St Lawrence’s Fiery Tears because the meteor shower comes near the date of the feast. We know these meteors as the Perseids because the appear to come from just off the constellation of Perseus the hero in our northern sky. Small bits of rocky material are the meteoroids that have been shed from Comet Swift-Tuttle on its previous passes near the sun strike the Earth’s atmosphere. Since the comet’s orbit nearly crosses the Earth’s orbit we pass through this ring of debris every year.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Perseid meteor shower radiant a about 2 a,m, during the period of the shower. Created using my LookingUp program.
My best Perseid photo. From the 70’s.
Bob Moler's Ephemeris Blog 