Archive
08/10/2016 – Ephemeris – The planets tonight
Ephemeris for Wednesday, August 10th. The Sun rises at 6:39. It’ll be up for 14 hours and 15 minutes, setting at 8:55. The Moon, at first quarter today, will set at 12:55 tomorrow morning.
Today we turn from the small meteoroids that orbit the Sun that are producing the Perseid Meteor Shower to the larger members of the solar family, namely the bright planets. Venus and Mercury are very low in the west-northwest and will set at 9:44 and 9:50 p.m. respectively. Jupiter is in the west in the evening. It will set at 10:19 p.m. Mars, Saturn and the star Antares start the evening in the south-southwestern sky as a tightening triangle, moving to the southwest during the evening. Antares, whose name means Rival of Mars is below Saturn with brighter Mars to the right. The Red Planet is back in Scorpius. It will set at 12:46 a.m. Mars is moving rapidly to the east against the stars. Saturn is spectacular in telescopes, with its rings. Saturn will set at 1:34 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus, Mercury and Jupiter at 9:25 p.m. (30 minutes after sunset), August 10, 2016. Created using Stellarium.
The planets, Moon and constellations at 10 p.m., August 10, 2016. Created using Stellarium.
The Moon as it might appear in binoculars tonight, August 10, 2016 at 10 p.m. Created using Stellarium.
Saturn and its moons at 10 p.m. August 10, 2016. Created using Cartes du Ciel (Sky Charts).
Planets at sunset and sunrise of a single night starting with sunset on the right on August 10, 2016. The night ends on the left with sunrise on August 11. Actually all the naked eye planets are in the evening sky. Also shown is the Perseid meteor shower radiant. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images. Created using my LookingUp program.
Also shown is the Perseid meteor shower radiant.
08/09/2016 – Ephemeris – A look at the Perseids progenitor
Ephemeris for Tuesday, August 9th. The Sun rises at 6:38. It’ll be up for 14 hours and 18 minutes, setting at 8:56. The Moon, 1 day before first quarter, will set at 12:23 tomorrow morning.
Comet Swift-Tuttle is the comet responsible for the Perseid Meteor Shower which is now ramping up and will reach its peak Thursday night and Friday morning. The comet was independently discovered by Swift and Tuttle in the summer of 1862. Based on three months of observations it was predicted to return after 120 years in 1982. After it failed to appear more work was done to refine the orbit, and to check for past appearances of the comet. Sure enough comets appearing to fit the orbit were found in 188 CE and 69 BCE, so a new prediction for the comet to reappear was made for 1992 by the late Dr. Brian Marsden of the Smithsonian Astrophysical Observatory. His revised prediction was only off by 17 days.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orbit of Comet 109P/Swift-Tuttle. Blue line is the comet’s orbit, coming from above (North). Credit NASA / JPL / Applet by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).
Orbit of Comet 109P/Swift-Tuttle. Blue line is the comet’s orbit, coming from above. That’s why the radiant is so far north. See yesterday’s post for the radiant point. Credit NASA / JPL / Applet by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).
These were generated a couple of years ago. However the comet won’t be back until 2122 give or take.
08/05/2016 – Ephemeris – Star party at NMC’s Rogers Observatory tonight
Ephemeris for Friday, August 5th. The Sun rises at 6:34. It’ll be up for 14 hours and 28 minutes, setting at 9:02. The Moon, 3 days past new, will set at 10:31 this evening.
There will be a star party this evening at Northwestern Michigan College’s Rogers Observatory hosted by the Grand Traverse Astronomical Society and the NMC Astronomy Club starting at 9 p.m. On tap, if it’s clear, will be Jupiter and the Moon early, then Mars and Saturn. Mars will appear quite small. As it gets darker the stars will appear. Some will show companion stars, while between the stars, what we call deep sky objects will be seen. Clusters of stars, and nebulae which can be either the birthplaces of stars or markers of dying stars. While other galaxies can be spotted our eyes are dazzled by our galaxy, the Milky Way spanning the sky from northeast to the south, in which these other objects dwell. The months of August and September are the months when the heart of the Milky Way is best seen.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Milky Way from the Sleeping Bear Dunes last August by Mark Stewart.
This year Saturn and Mars will be in the picture. In this picture Saturn is low and to the right.
08/04/2016 – Ephemeris – Mars’ lookalike star
Ephemeris for Thursday, August 4th. The Sun rises at 6:32. It’ll be up for 14 hours and 30 minutes, setting at 9:03. The Moon, 2 days past new, will set at 10:01 this evening.
As it gets dark this evening a bright reddish star will appear low in the south. It will appear to twinkle mightily. It is not the planet Mars, which is brighter and to the right of it, but its rival the star Antares in Scorpius the scorpion. The star’s name, Antares, notes the rivalry. “Ant” means anti, while “Ares” is the Greek name for the Roman god Mars. Antares literally means “Rival of Mars”. Antares appears red due to its cool surface temperature of 3,600 Kelvin, much cooler than the sun’s 6,000 Kelvin, while Mars is red due to rust. Watch nightly as Mars slowly approaches Antares, and will pass it on the 24th. Being always low in the sky, Antares’ spectacular twinkling has sparked more than a few emails about a strange light in the sky.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Animation of Mars approaching Antares from August 4 to the 24th, 2016 at 10 p.m. Created using Stellarium and GIMP.
08/03/2016 – Ephemeris – Jupiter is slipping toward the setting Sun
Ephemeris for Wednesday, August 3rd. The Sun rises at 6:31. It’ll be up for 14 hours and 33 minutes, setting at 9:05. The Moon, 1 day past new, will set at 9:29 this evening.
Venus and Mercury are in the evening sky but too close to the Sun to be easily seen. Check below for more information on the apparent interactions between the two. Jupiter will join the fray later this month. Jupiter is in the west in the evening. It will set at 10:44 p.m. Mars starts the evening in the south-southwestern sky, moving to the southwest. It’s right of its dimmer look-a-like star Antares, whose name means Rival of Mars. The Red Planet is back in Scorpius. The planet will set at 1:07 a.m. Mars is resuming its rapid eastward motion against the stars. The ringed planet Saturn is low in the south. It’s to the left of Mars. Saturn will pass due south at 9:25 p.m. and will set at 2:02 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus, Mercury the day old Moon (not really visible) and Jupiter at 9:25 p.m. (20 minutes after sunset), August 3, 2016. Created using Stellarium.
Spotting the Moon and these planets requires a Lake Michigan horizon and may be futile. The farther one is to the south the greater the angle that the line of planets make with the horizon. This is not a good apparition of Mercury for us, but a good one for folks in the southern hemisphere.
The planets and constellations at 10 p.m., August 3, 2016. Created using Stellarium.
Jupiter and its satellites at 10 p.m., August 3, 2016. It will be close to the horizon and fuzzy in telescopes. Created using Cartes du Ciel (Sky Charts).
Saturn and its moons at 10 p.m. August 3, 2016. Created using Cartes du Ciel (Sky Charts).
Planets at sunset and sunrise of a single night starting with sunset on the right on August 3, 2016. The night ends on the left with sunrise on August 4. Actually all the naked eye planets are in the evening sky. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images. Created using my LookingUp program.
08/02/2016 – Ephemeris – The Scorpion has visitors this year
Ephemeris for Tuesday, August 2nd. The Sun rises at 6:30. It’ll be up for 14 hours and 35 minutes, setting at 9:06. The Moon is new today, and won’t be visible.
There’s a large constellation located low in the south as it gets dark about 10:30 tonight It’s Scorpius the scorpion. Its brightest star is Antares in its heart, a red giant star whose name means “Rival of Mars”. From Antares to the right is a star then a vertical arc of three stars that is its head. The Scorpion’s tail is a line of stars running down to the left of Antares swooping near the horizon before coming back up and ending in a pair of stars that portray his poisonous stinger. This year the planet Saturn appears almost directly above Antares. Tonight Mars is right of Antares. On the 23rd of this month Mars will pass just above
Antares, between it and Saturn, making line of three bright objects. Mars is currently brighter than Antares.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Scorpius with Mars and Saturn at 10:30 p.m. August 2, 2016. Created using Stellarium.
The red lines are the official constellation boundaries by the International Astronomical Union. From the look of some of the boundaries, astronomers apparently gerrymander as well as our politicians.
For those unfamiliar with gerrymandering put “gerrymander” in your favorite search engine or Wikipedia.
08/01/2016 – Ephemeris – Previewing August skies
Ephemeris for Monday, August 1st. The Sun rises at 6:29. It’ll be up for 14 hours and 38 minutes, setting at 9:07. The Moon, 1 day before new, will rise at 6:19 tomorrow morning.
Let’s look ahead at the month of August in the skies. Daylight hours will decrease from 14 hours and 38 minutes today to 13 hours 15 minutes on the 31st. The altitude of the sun at local noon, that is degrees of angle above the horizon will decrease from 63 degrees today to just over 53 degrees on the 31st. Straits area listeners can subtract one more degree from those angles. Local noon, when the sun is due south, is about 1:43 p.m. The big event of the month will be in the early morning sky: The Perseid meteor shower will reach its peak on Friday morning the 12th. However you’ll have to wait until after 1:30 a.m. for the moon to set. But that will allow viewing of the shower up to 3 hours of the peak. I’ll have more then.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
August Star Chart
Star Chart for August 2016. Created using my LookingUp program. To enlarge in Firefox right-click on image then click View image.
The planets and stars are plotted for the 15th at 10 p.m. EDT. That is chart time. Note, Traverse City is located approximately 45 minutes behind our time meridian. (An hour 45 minutes behind our daylight saving time meridian.) To duplicate the star positions on a planisphere you may have to set it to 1:45 earlier than the current time if you are near your time meridian.
Evening nautical twilight ends at 10:23 p.m. EDT on the 1st, increasing to 9:26 p.m. EDT on the 31st.
Morning nautical twilight starts at 5:14 a.m. EDT on the 1st, and decreasing to 5:58 a.m. EDT on the 31st.
Add a half hour to the chart time every week before the 15th and subtract a half hour for every week after the 15th. Before the 13th also subtract an hour for Standard Time.
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
- Extend the arc to a spike to point to Spica.
- The Summer Triangle is outlined in red. Vega in Lyra (Lyr), Deneb in Cygnus (Cyg) and Altair in Aquila (Aql).
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.
Date Time Event Aug 01 Mo Venus: 15.3° E 02 Tu 16:45 New Moon 04 Th 02:19 Moon-Venus: 3.1° N 04 Th 18:12 Moon-Mercury: 0.6° N 05 Fr 03:48 Moon Ascending Node 05 Fr 07:57 Venus-Regulus: 1° N 05 Fr 23:28 Moon-Jupiter: 0.2° N 09 Tu 20:05 Moon Apogee: 404300 km 10 We 14:21 First Quarter 12 Fr 08:10 Moon-Saturn: 4° S 12 Fr 08:26 Perseid Shower: ZHR = 90 14 Su 09:05 Moon South Dec.: 18.5° S 16 Tu 16:59 Mercury Elongation: 27.4° E 18 Th 05:27 Full Moon 19 Fr 10:14 Moon Descending Node 20 Sa 01:34 Mercury-Jupiter: 3.8° N 21 Su 21:20 Moon Perigee: 367000 km 24 We 01:09 Mars-Antares: 1.8° N 24 We 21:11 Mars-Saturn: 4.3° N 24 We 23:41 Last Quarter 25 Th 12:21 Moon-Aldebaran: 0.2° S 27 Sa 07:17 Moon North Dec.: 18.5° N 27 Sa 17:53 Venus-Jupiter: 0.1° N 28 Su 16:09 Mercury-Venus: 5° N Sep 01 Th Venus: 23.5° E
07/29/2016 – Ephemeris – Aquila the Eagle, third constellation of the Summer Triangle
Ephemeris for Friday, July 29th. The Sun rises at 6:26. It’ll be up for 14 hours and 45 minutes, setting at 9:11. The Moon, 3 days past last quarter, will rise at 3:20 tomorrow morning.
Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair is one of the stars of the Summer Triangle, a group of three bright stars seen now in the eastern sky in the evening. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan, which I talked about Tuesday, above and left of Aquila, flying in the opposite direction.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aquila the Eagle in the southeastern sky. Created using Stellarium.
07/28/2016 – Ephemeris – Two upcoming meteor showers plus an occultation tomorrow morning
Ephemeris for Thursday, July 28th. The Sun rises at 6:25. It’ll be up for 14 hours and 47 minutes, setting at 9:12. The Moon, 2 days past last quarter, will rise at 2:31 tomorrow morning.
We have a couple of meteor showers of note coming up. The first is the Southern Delta Aquariids which will peak on the 30th. The radiant point for these meteors will rise around midnight in the southeast. Their numbers and their brightness are not very great. The Perseid meteor shower peak will have interference from the waxing gibbous moon drowning out all but the brightest meteors on the evening of August 11 and morning of he 12th. However the Perseids have a long run up to their peak, so their numbers will grow after the moon sets. The Perseid radiant is circumpolar for Northern Michigan, meaning it never sets, so some Perseid meteors can always be seen at night. Their radiant will be low in the northeastern sky in the evening and much higher in the northeast just before dawn.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addenda
Approximate Radiant of the South Delta Aquariid meteor shower. The radiant does move over the several weeks of the shower to the east. Created using my LookingUp program.
Perseid Meteor Shower radiant after midnight. Created using my LookingUp program.
Update: Occultation of Aldebaran tomorrow morning
The area where the occultation of Aldebaran will be visible. The area bordered by the white lines is where the occultation will occur with the Sun below the horizon. Credit IOTA’s Occult 4 program.
There will be an occultation of Aldebaran by the Moon centered on 11:16 UT (7:16 a.m. EDT) July 29, 2016. Our area (Michigan) cannot see the event, being too far north. It will be visible south of a line containing the state of Maine down through Texas. Universe Today has information on grazing occultation possibilities: http://www.universetoday.com/129841/spectacular-aldebaran-graze-july-29/
07/27/2016 – Ephemeris – All the bright planets are now in the evening sky
Note: Mercury and Venus are in the evening sky but too low to be easily spotted, even with a Lake Michigan horizon, so I did not cover them in the program below but see the addendum.
Ephemeris for Wednesday, July 27th. The Sun rises at 6:24. It’ll be up for 14 hours and 49 minutes, setting at 9:13. The Moon, 1 day past last quarter, will rise at 1:48 tomorrow morning.
Our evening planets are moving with the stars to the west, and setting almost a half hour earlier each week. Jupiter is in the west in the evening. It will set at 11:08 p.m. Binoculars can make out some of Jupiter’s moons, but a telescope is required to see all four bright moons and Jupiter’s cloud features. Mars starts the evening in the southern sky, moving to the southwest. It’s above and right of its dimmer look-a-like star Antares, whose name means Rival of Mars. The planet will set at 1:24 a.m. The Earth is pulling ahead of Mars so it’s now 65 million miles away and tiny in telescopes. The ringed planet Saturn is low in the south. It’s to the left of Mars. Saturn will pass due south at 9:53 p.m. and will set at 2:30 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus, Mercury and Jupiter at 9:45 p.m. a half hour after sunset. Venus is 2 degrees above the horizon, and Mercury is 4 degrees. Created using Stellarium.
Jupiter, Mars and Saturn with the southern summer constellations at 10:30 p.m., July 27, 2016. Created using Stellarium.
Jupiter and its Galilean moons at 10:30 p.m. July 27, 2016. Jupiter’s apparent diameter will be 32.3″. Europa will be transiting the planet, and will probably not visible. Created using Cartes du Ciel (Sky Charts).
Saturn and its moons at 10:30 p.m. July 27, 2016. The apparent diameter of the planet will be 17.6″, larger than Mars’ disk. The rings span 41.1″, larger than the apparent diameter of Jupiter. Created using Cartes du Ciel (Sky Charts).
Planets at sunset and sunrise of a single night starting with sunset on the right on July 27, 2016. The night ends on the left with sunrise on July 28. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images.
