Archive
01/03/2017 – Ephemeris – The Earth will be closest to the Sun tomorrow
Ephemeris for Tuesday, January 3rd. The Sun will rise at 8:19. It’ll be up for 8 hours and 55 minutes, setting at 5:15. The Moon, 2 days before first quarter, will set at 11:06 this evening.
The Earth has as elliptical orbit of the Sun, as do all planets. It is close to circular but not quite. The Earth’s distance from the Sun is 93 million miles (150 million km) plus or minus a million and a half miles. Tomorrow at about 6 a.m. the Sun will be at a point called perihelion, only 91.4 million miles (147 million km). It makes only a tiny difference in the Sun’s intensity, but since the Earth moves faster when closest to the Sun, it makes winter the shortest season at 89 days. Aphelion, Earth’s farthest distance from the sun occurs around July 4th which makes summer the longest season at 93 days. The eccentricity of an orbit can modify the seasons, but the seasons themselves are caused by the tilt of the planet’s axis alone.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Earth’s orbit, somewhat exaggerated, showing perihelion and the seasons. Credit “Starts with a Bang” blog by Ethan Siegel.
01/02/2017 – Ephemeris – Looking ahead at January 2017
Ephemeris for Monday, January 2nd. 2017. The Sun will rise at 8:19. It’ll be up for 8 hours and 54 minutes, setting at 5:14. The Moon, 3 days before first quarter, will set at 10:00 this evening.
Let’s look ahead at the month of January. Today we will have out latest sunrise at 8:19. That time will drop to 8:02 on the 31st. Sunset times are already increasing, now at 5:14, will extend to 5:50 at month’s end, which will push the daylight hours to 9 hours 48 minutes by then. The altitude of the Sun at local noon will increase from under 23 degrees today to 28 degrees at month’s end. Tomorrow morning will see the peak of the Quadrantid meteor shower. They will be best seen in the early morning and seem to come from near the handle of the Big Dipper, where possibly more than 60 meteors an hour might be seen. On Wednesday we will reach our closest distance from the Sun of the year at 91.3 million miles.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
January Star Charts
Evening
Star Chart for January 2017 evenings. Created using my LookingUp program. Click on image to enlarge.
Morning
Star Chart for January 2017 mornings. Created using my LookingUp program. Click on image to enlarge.
Since the night time hours are long I’ve decided to add a morning star chart .
The planets and stars are plotted for the 15th at 9 p.m. EST, and again at 6 a.m. Those are chart times. Note, Traverse City is located approximately 45 minutes behind our time meridian. (An hour 45 minutes behind our daylight saving time meridian. during EDT and 45 minutes behind our daylight standard time meridian. during EST). To duplicate the star positions on a planisphere you may have to set it to 1:45 or 0:45 earlier than the current time if you were near your time meridian.
Add a half hour to the chart time every week before the 15th and subtract a half 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
- Follow the arc of the handle of the Big Dipper to the star Arcturus, and
- Straighten to a spike to Spica
- QuadR is the Radiant of the Quadrantid meteor shower
Evening nautical twilight ends at 6:22 p.m. EST on the 1st, increasing to 6:55 p.m. EST on the 31st.
Evening astronomical twilight ends at 6:57 p.m. EST on the 1st, increasing to 7:29 p.m. EST on the 31st.
Morning astronomical twilight starts at 6:35 a.m. EST on the 1st, and increasing to 6:23 a.m. EST on the 31st.
Morning nautical twilight starts at 7:10 a.m. EST on the 1st, and Increasing to 6:57 a.m. EST on the 31st.
NASA 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 Time and follow the time change dates.
Date Time Event Jan 01 Su Venus: 46.8° E 02 Mo 04:20 Moon-Venus: 2° S 02 Mo 13:14 Moon Descending Node 03 Tu 01:47 Moon-Mars: 0.3° S 03 Tu 09:10 Quadrantid Meteor Shower: ZHR = 120 04 We 05:59 Perihelion: 0.9833 AU 05 Th 14:47 First Quarter 09 Mo 04:03 Mercury-Saturn: 6.7° N 09 Mo 09:07 Moon-Aldebaran: 0.4° S 10 Tu 01:07 Moon Perigee: 363200 km 11 We 04:32 Moon North Dec.: 18.9° N 12 Th 06:34 Full Moon 12 Th 07:59 Venus Greatest Elongation: 47.1° East 14 Sa 23:07 Moon-Regulus: 0.9° N 15 Su 05:45 Moon Ascending Node 19 Th 00:26 Moon-Jupiter: 3° S 19 Th 04:59 Mercury Greatest Elongation: 24.1° West 19 Th 17:14 Last Quarter 21 Sa 19:14 Moon Apogee: 404900 km 24 Tu 05:37 Moon-Saturn: 4° S 25 We 06:59 Moon South Dec.: 18.9° S 25 We 19:46 Moon-Mercury: 4° S 27 Fr 19:07 New Moon 29 Su 17:21 Moon Descending Node 31 Tu 01:12 Jupiter-Spica: 3.5° N 31 Tu 09:34 Moon-Venus: 4.2° N 31 Tu 20:09 Moon-Mars: 2.4° N Feb 01 We Venus: 45.5° E
January 2017 Calendar
LU Ephemeris of Sky Events for Interlochen/TC January, 2017 Local time zone: EST +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Sun 1| 08:20a 05:13p 08:53 | 06:23p 07:09a | Set 08:55p 13%| |Mon 2| 08:20a 05:14p 08:54 | 06:24p 07:09a | Set 10:00p 21%| |Tue 3| 08:20a 05:15p 08:55 | 06:25p 07:10a | Set 11:06p 31%| |Wed 4| 08:20a 05:16p 08:56 | 06:26p 07:10a | Set 12:14a 41%| |Thu 5| 08:19a 05:17p 08:57 | 06:27p 07:10a |F Qtr Set 01:24a 52%| |Fri 6| 08:19a 05:18p 08:58 | 06:28p 07:09a | Set 02:35a 63%| |Sat 7| 08:19a 05:19p 08:59 | 06:29p 07:09a | Set 03:47a 74%| +------+-----------------------+----------------+-----------------------+ |Sun 8| 08:19a 05:20p 09:01 | 06:30p 07:09a | Set 04:58a 83%| |Mon 9| 08:19a 05:21p 09:02 | 06:31p 07:09a | Set 06:07a 91%| |Tue 10| 08:18a 05:22p 09:04 | 06:32p 07:09a | Set 07:11a 97%| |Wed 11| 08:18a 05:23p 09:05 | 06:33p 07:09a | Set 08:07a 100%| |Thu 12| 08:17a 05:25p 09:07 | 06:34p 07:08a |Full Rise 06:04p 100%| |Fri 13| 08:17a 05:26p 09:08 | 06:35p 07:08a | Rise 07:12p 97%| |Sat 14| 08:16a 05:27p 09:10 | 06:36p 07:08a | Rise 08:20p 92%| +------+-----------------------+----------------+-----------------------+ |Sun 15| 08:16a 05:28p 09:12 | 06:37p 07:07a | Rise 09:26p 85%| |Mon 16| 08:15a 05:30p 09:14 | 06:38p 07:07a | Rise 10:31p 77%| |Tue 17| 08:15a 05:31p 09:16 | 06:39p 07:06a | Rise 11:33p 68%| |Wed 18| 08:14a 05:32p 09:18 | 06:40p 07:06a | Rise 12:33a 59%| |Thu 19| 08:13a 05:33p 09:20 | 06:42p 07:05a |L Qtr Rise 01:32a 49%| |Fri 20| 08:13a 05:35p 09:22 | 06:43p 07:05a | Rise 02:30a 40%| |Sat 21| 08:12a 05:36p 09:24 | 06:44p 07:04a | Rise 03:27a 31%| +------+-----------------------+----------------+-----------------------+ |Sun 22| 08:11a 05:37p 09:26 | 06:45p 07:03a | Rise 04:23a 23%| |Mon 23| 08:10a 05:39p 09:28 | 06:46p 07:03a | Rise 05:18a 15%| |Tue 24| 08:09a 05:40p 09:30 | 06:47p 07:02a | Rise 06:09a 9%| |Wed 25| 08:08a 05:42p 09:33 | 06:49p 07:01a | Rise 06:57a 4%| |Thu 26| 08:07a 05:43p 09:35 | 06:50p 07:00a | Rise 07:41a 1%| |Fri 27| 08:06a 05:44p 09:37 | 06:51p 07:00a |New Set 05:43p 0%| |Sat 28| 08:05a 05:46p 09:40 | 06:52p 06:59a | Set 06:45p 1%| +------+-----------------------+----------------+-----------------------+ |Sun 29| 08:04a 05:47p 09:42 | 06:54p 06:58a | Set 07:51p 4%| |Mon 30| 08:03a 05:49p 09:45 | 06:55p 06:57a | Set 08:58p 10%| |Tue 31| 08:02a 05:50p 09:47 | 06:56p 06:56a | Set 10:06p 17%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunset and sunrise
12/30/2016 – Ephemeris – Looking ahead at the eclipses of 2017
Ephemeris for Friday, December 30th. The Sun will rise at 8:19. It’ll be up for 8 hours and 51 minutes, setting at 5:11. The Moon, 1 day past new, will set at 6:53 this evening.
Looking ahead at astronomical events of the 2017. There is one big one that all of us astronomers, both amateur and professional are looking forward to. That is the total eclipse of the Sun on August 21st, where the center of the Moon’s shadow will sweep across the continental United States from Oregon to South Carolina. The closest this path of totality will get to our area is around Carbondale, Illinois. For the Grand Traverse area the Sun will be some 75% covered by the Moon. As kind of a warm up event, we’ll have a slight eclipse of the Moon February 10th, where the Moon will enter the Earth’s outer partial shadow, nearly grazing the Earth’s inner shadow in the early evening. It’s called a penumbral lunar eclipse.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
This is the maximum of the February 10th penumbral lunar eclipse. The Moon will appear to move diagonally down to the left. It is shown at maximum eclipse at 7:45 p.m. (0:45 UT February 11). Created using Cartes du Ciel.
Shadows are, of course, invisible unless they are cast on an object, so the Moon would appear alone, though the upper left part of it would be noticeably dimmer than the opposite side.
A screen cap of the map showing the path of totality of the August 21, 2017 total solar eclipse from NASA’s eclipse page. Credit: NASA and Google Maps. Click on image to enlarge.
Click here to go to the page where this interactive map is located. The magenta marker with GD is the point with the greatest duration of totality of 2 minutes 40.2 seconds. The green marker with GE denotes where the Moon’s umbral shadow is the widest. Clicking on any point on the map will pop a balloon shows all the eclipse information for viewing it from that place. The partial eclipse can be seen from all fifty states, though in Hawai’i the Sun rises with the eclipse in progress.
Here in the Grand Traverse Region, the Moon will encroach on about 8/10ths of the Sun’s diameter, covering 75% of the Sun’s face.
What the maximum eclipse would look like with proper filtering at Traverse City, MI. Created using Stellarium.
Eclipse Times for Traverse City
Eclipse Starts 12:58:03 p.m.
Maximum Eclipse 2:20:15 p.m.
Eclipse Ends 3:40:51 p.m.
Magnitude of the eclipse 0.798
Obscuration of the Sun 75.1%
This is an inkling of what a totally eclipsed Sun looks like. No photograph can do it justice. Ya gotta be there! The solar corona displayed during the July 10, 1972* total solar eclipse from Prince Edward Island. Credit Bob Moler.
* Update: Thanks for the heads up on the typo: NationalEclipse.com.
Program Note:
I’ve developed a PowerPoint slide presentation highlighting my four total eclipses and a look at future eclipses. I will be happy to give this presentation to school groups and organizations free of charge except for mileage reimbursement over 50 miles. Contact me at bob@bjmoler.org.
December 31st – the longest day, really.
December 31st will be 24 hours and 1 second long. This “leap second” will be added as the 61st second of the minute 6:59 p.m. EST (23:59 UT). The reason is that the Earth’s rotation is slowing down ever so slightly, compared to the atomic clocks at the Bureau of Time. There is some discussion of eliminating this leap second. Most scientists want to use a constant time stream, and don’t give a hang about the rotation of the Earth. The exact time which is also affected by special and general relativity is used by GPS navigation satellites. A one second jump in time, at our latitude (45° north) is equivalent of the earth’s rotation of about two tenths of a mile. I hope everyone’s coordinated on this.
12/29/2016 – Ephemeris – Astronomical milestones of 2016
Ephemeris for Thursday, December 29th. The Sun will rise at 8:19. It’ll be up for 8 hours and 50 minutes, setting at 5:10. The Moon is new today, and won’t be visible.
Looking back at 2016 the biggest astronomical news was the detection of gravitational waves coming from two separate collisions of black holes far beyond our Milky Way galaxy. The two detectors in Washington state and in Louisiana recorded these events in September and December 2015, but the first announcement was made in February this year after the signals were cleaned up and studied. The year saw the end of the European Space Agency’s Rosetta Mission to the comet we’ve come to call 67P after orbiting it for over two years. The Opportunity and Curiosity rovers continued their exploration of Mars along with a fleet of satellites. On a sad note, we lost pioneering Mercury astronaut John Glenn at the age of 95.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The chirp heard ’round the world and indeed the universe. Credit: LIGO/Abbot et al. 2016. Hat tip: Phil Plait, the Bad Astronomer.
Rosetta, Final orbit. Credit & copyright European Space Agency (ESA)
12/28/2016 – Ephemeris – Our last weekly look at the bright planets for 2016
Ephemeris for Wednesday, December 28th. The Sun will rise at 8:19. It’ll be up for 8 hours and 50 minutes, setting at 5:09. The Moon, 1 day before new, will rise at 8:16 tomorrow morning.
Let’s take our last look at the bright planets for 2016. In the southeast to south before 7:30 these mornings. Jupiter can be glimpsed as the sky brightens. Jupiter will rise tomorrow at 1:53 a.m. Venus and Mars are in the evening sky. At 6:30 p.m. these planets will be seen in the southwestern sky. Venus is unmistakable as the brilliant evening star, Mars will be above and left of it and much dimmer. Venus will set at 9:01 p.m. Mars will set at 10:12. Mars’ setting time hasn’t changed much in the last 2 months. Venus is slowly heading northward for the rest of it’s evening appearance, and is moving higher in the sky, and is closing in on it’s greatest eastern elongation from the Sun.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus and Mars in the evening twilight of about an hour and tree quarters after sunset. 7 p.m. December 28, 2016. Created using Stellarium. Click on the image to enlarge.
Venus as it might appear in a telescope at 7 p.m. December 28, 2016. It is 21.1′ (seconds or arc) in diameter. and 58% illuminated by the Sun.
Jupiter among a preview of the spring constellations at 7 a.m. now. Created using Stellarium. Click on the image to enlarge.
Jupiter and its moons this morning, December 28, 2016 at 7 a.m. Note the compact grouping. Created using Cartes du Ciel (Sky Charts).
Jupiter and its moons tomorrow morning, December 29, 2016 at 7 a.m. Note that Io is missing. It was eclipsed by Jupiter’s shadow on the west (right) side of the planet at 6:10 a.m. (11:10 UT). It will reappear from behind Jupiter on the other side at 14:33 UT for observers a few time zones west of here. Created using Cartes du Ciel (Sky Charts).
Planets and Moon at sunset and sunrise of a single night starting with sunset on the right on December 28, 2016. The night ends on the left with sunrise on December 29. Click on image to enlarge. Created using my LookingUp program.
12/27/2016 – Ephemeris – The stars of Orion
Ephemeris for Tuesday, December 27th. The Sun will rise at 8:19. It’ll be up for 8 hours and 49 minutes, setting at 5:09. The Moon, 2 days before new, will rise at 7:26 tomorrow morning.
The large and bright constellation of Orion the hunter is in the southeast at 9 p.m., with the bright star Sirius below it near the horizon. The equally spaced line of three stars of Orion’s belt are nearly vertical and point down to Sirius, also known as the Dog Star in Canis Major, Orion’s greater dog. The whole of its constellation stars aren’t up at 9 p.m., but they will all clear the horizon by 10 p.m. Those three belt stars are in the center of an elongated rectangle of stars At the top left of Orion’s shoulder stars is the red giant star Betelgeuse. The right shoulder star is Bellatrix. Both Bellatrix and Sirius along with the names of other stars and constellations should be familiar to fans of the Harry Potter novels and movies, as members of the house of Black. The knee stars at the bottom of the rectangle are, from left to right Saiph and the brilliant blue giant star Rigel. Between his belt and knees are stars of his sword.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion, star names, and constellation art animation position for 9 p.m. December 27. Created using Stellarium and GIMP. Artist: Johan Meuris.
In the image above I’ve added the belt star names, though they are generally covered in a program of their own.
12/26/2016 – Ephemeris – Orion takes its place as the central winter constellation
Ephemeris for Monday, December 26th. The Sun will rise at 8:19. It’ll be up for 8 hours and 49 minutes, setting at 5:08. The Moon, 3 days before new, will rise at 6:33 tomorrow morning.
The great constellation of Orion the hunter has claimed his rightful position as the central winter constellation. It’s the most famous constellation of all. Think the Big Dipper is a big deal? They can’t even see it from the large population centers of Australia. Parts of Orion can be seen from every part of the Earth from pole to pole. Orion’s distinctive feature is his belt of three bright stars in a row. This tilted belt is in the center of a large rectangle of bright stars. The upper left star is Betelgeuse a red giant star. The lower right star is Rigel a blue giant star. Orion was an unlucky fellow of Greek myth. One wonders why he gets this splashy constellation in Winter while Hercules gets a dim upside down constellation in the spring sky.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion and the head of Taurus photograph by myself January 4, 2016 at 11:30 p.m. It’s a stack of unguided 20 second exposures.
Orion from mid latitudes north of the equator. Orion would be upside down if viewed south of the equator. Created using Stellarium.
The Ephemeris radio programs are very short (59 seconds) so I will visit Orion several times during the winter to explore its mythology and deep sky wonders within, or search past posts for Orion.
12/23/2016 – Ephemeris – Another possible set of events that could have been the Star of Bethlehem
Ephemeris for Friday, December 23rd. The Sun will rise at 8:18. It’ll be up for 8 hours and 48 minutes, setting at 5:06. The Moon, 3 days past last quarter, will rise at 3:43 tomorrow morning.
The brilliant planet Venus is out evening star now, and one could say that’s its our Christmas Star. And perhaps it was, or was part of the Star of Bethlehem. Back in August of 3 BC the planet Jupiter and Venus appeared to come very close to one another. The term for such an apparent close approach is called a conjunction. Astrologers make a big deal out of such a chance alignment. It’s like a trick photo of someone in the foreground appearing to hold up or leaning on a more distant object. Anyway, 10 months later in June of 2 BC Jupiter again appeared to join Venus, this time so close they could not be separated by the human eye. This all occurred against the constellation of Leo the lion which in Genesis is the symbol of Judah.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus and Mars in the twilight last night at 6 p.m., December 22, 2016. Photograph by Bob Moler. Click on the image to enlarge.
I have more information on this set of conjunctions in my December 2 post announcing my program on the Star of Bethlehem: https://bobmoler.wordpress.com/2016/12/02/12022016-ephemeris-my-talk-about-the-star-of-bethlehem-is-tonight/
12/22/2016 – Ephemeris – Could Jupiter and Saturn have combined to be the Star of Bethlehem?
Ephemeris for Thursday, December 22nd. The Sun will rise at 8:17. It’ll be up for 8 hours and 48 minutes, setting at 5:05. The Moon, 2 days past last quarter, will rise at 2:45 tomorrow morning.
This morning the planet Jupiter is seen right below the waning crescent Moon. It reminds me of one of the possible answers to the questions to what the Star of Bethlehem was. Back in 7 BC Jupiter passed Saturn three times in that year. This is a reasonably rare occurrence especially against a particular constellation, which in this case was Pisces the fish, which would occur every 800 plus years. Early in the run of this program there was another so-called triple conjunction of Jupiter and Saturn. This time it was against the constellation of Virgo the virgin in 1980 and 81. Jupiter passes Saturn every 20 years, but only when it does so when they are opposite the Sun in the sky is there a chance for a triple conjunction. Tomorrow I’ll look at two really close conjunctions of Jupiter and Venus that also could have been seen by the Magi as the Star of Bethlehem.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter and the Moon at 7 a.m. this morning, December 22, 2016. Created using Stellarium.
Jupiter and Saturn pass each other three times from May to December in 7 BC. Created using Cartes du Ciel (Sky Charts) and GIMP. Click image to enlarge.
12/21/2016 – Ephemeris – A look at the bright planets at the start of winter
Ephemeris for the winter solstice Wednesday, December 21st. The Sun will rise at 8:17. It’ll be up for 8 hours and 48 minutes, setting at 5:05. The Moon, 1 day past last quarter, will rise at 1:46 tomorrow morning.
Let’s look at the naked eye planets now that it’s officially winter as of 5:45 a.m. In the east-southeast before 7:30 these mornings. Jupiter can be glimpsed in the morning twilight. Jupiter will rise tomorrow at 2:16 a.m. and will appear below the Moon. Venus and Mars are in the evening sky. At 6 p.m. these planets will be seen in the southwest and low in the sky. Venus is unmistakable as the brilliant evening star, Mars will be above and left of it. Venus will set at 8:46. Mars will set at 10:12. Mars’ setting time hasn’t changed much in the last 2 months. Venus is slowly heading northward for the rest of it’s evening appearance, and is moving higher in the sky, and is closing in on it’s greatest eastern elongation from the Sun.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus and Mars in the evening twilight of about an hour after sunset. 6 p.m. December 21, 2016. Created using Stellarium.
Venus as it might be seen in a telescope at 6 p.m. December 21, 2016. Created using Stellarium.
Jupiter and the Moon at 7 a.m. December 22, 2016. Created using Stellarium.
The Moon as it might appear in binoculars at 7 a.m. December 22, 2016. Created using Stellarium.
Jupiter and its Galilean moons at 7 a.m. December 22, 2016. Io is behind Jupiter at this time, however it will clear the planet by 7:38 a.m. EST (12:38 UT). Created using Cartes du Ciel (Sky Charts).
Update 8:10 a.m.
Planets and Moon at sunset and sunrise of a single night starting with sunset on the right on December 21, 2016. The night ends on the left with sunrise on December 22. Click on image to enlarge. Created using my LookingUp program.
