Archive
09/11/2015 – Ephemeris – Astronomy from the dark skies of the Sleeping Bear Dunes this Saturday
Ephemeris for Friday, September 11th. The Sun will rise at 7:16. It’ll be up for 12 hours and 44 minutes, setting at 8:01. The Moon, 2 days before new, will rise at 6:39 tomorrow morning.
Tomorrow night will be the next to the last Star Party at the Sleeping Bear Dunes National Lakeshore of the year. It will be at the Dune Climb in the Parking lot nearest to the dunes. Featured will be the wonders of the Milky Way including globular and galactic star clusters and planetary and emission nebulae. The event starts at 9 p.m. We are entering the second eclipse season of the year.
On Sunday there will be a partial solar eclipse visible from South Africa, the Southern Ocean and part of Antarctica. Eclipses occur in no less a grouping than pairs, solar and lunar, the next eclipse is 16 days away. It will be total lunar eclipse visible from here on Sunday evening the 27th. In the week after next I’ll tell you all about it.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Star Party at the Dunes Overlook. Credit: Eileen Carlisle. I still don’t have a good picture of a star party at the Dune Climb where the dune rises up and blocks the lower 20º of the western sky.
Partial Solar Eclipse of September 13, 2-15. Credit: NASA/GSFC/Fred Espenak.
09/10/2015 – Ephemeris – Andromeda the chained maiden
Ephemeris for Thursday, September 10th. The Sun will rise at 7:15. It’ll be up for 12 hours and 47 minutes, setting at 8:03. The Moon, 3 days before new, will rise at 5:40 tomorrow morning.
In the east at 10 this evening can be found a large square of stars, the Great Square of Pegasus the flying horse. The square is standing on one corner. What look like its hind legs stretching to the left from the left corner star is another constellation, Andromeda the chained maiden. She is seen in the sky as two diverging curved strings of stars that curve upward. She was rescued by the hero Perseus, a nearby constellation, riding his steed Pegasus. Andromeda’s claim to astronomical fame is the large galaxy seen with the unaided eye just above the upper line of stars. The Great Andromeda Galaxy is two and a half million light years away. To the unaided eye the galaxy appears as a small smudge of light. In binoculars the galaxy is a delicate spindle of light. The galaxy is known as M31, the 31st object on Charles Messier’s list of fuzzy objects that aren’t comets.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Andromeda at 10 p.m. with the Great Andromeda Galaxy. Created using Stellarium.
09/09/2015 – Ephemeris – Saturn is in the evening sky but the planet action is moving to the morning
Ephemeris for Wednesday, September 9th. The Sun will rise at 7:14. It’ll be up for 12 hours and 50 minutes, setting at 8:05. The Moon, half way from last quarter to new, will rise at 4:42 tomorrow morning.
Lets look for the bright planets for this week. Saturn is alone in the evening sky spotted low in the southwestern sky near the bright star Antares to its left. It will set at 11:06 p.m. The rest of the planet action has moved to the morning sky. Venus, the morning star, will rise at 4:42 a.m. a bit north of east. Tomorrow morning the thin crescent Moon will appear just to the left of it. Much dimmer Mars will be to the left of the Moon, and will rise at 4:52 a.m. in the east-northeast. Mars will rapidly fall behind Venus. Jupiter is beginning to be visible in the morning sky and will rise at 6:16, almost an hour before the Sun. Mercury, though in the evening sky sets too soon after the Sun to be visible. Jupiter is too close to the Sun on thee morning side to be seen.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Saturn with the Zodiacal constellations of Libra, Scorpius and Sagittarius as the Teapot at 9:30 p.m. September 9, 2015. Created using Stellarium.
What Saturn and its moons might appear like in a telescope at 9:30 p.m., September 9, 2015. Small telescopes will show only the moon Titan. Created using Stellarium.
Looking east at Venus, the Moon and Mars at 6 a.m. September 10, 2015. Created using Stellarium.
This is a chart showing the sunrise and sunset skies for September 9, 2015 showing the location of the planets and the Moon at that time. Created using my LookingUp program. Click on the image to enlarge.
09/08/2015 – Ephemeris – Pegasus flies again
Ephemeris for Tuesday, September 8th. The Sun will rise at 7:13. It’ll be up for 12 hours and 53 minutes, setting at 8:07. The Moon, 3 days past last quarter, will rise at 3:44 tomorrow morning.
As summer wanes and the Sagittarius teapot tips its contents on the southwestern horizon the constellations of autumn rise in the east. I’ve already mentioned Cassiopeia, which is so far north it never really leaves us in northern Michigan. Pegasus the flying horse of Greek mythology is perhaps the most famous of the autumn constellations, and easiest to find. Its body, a large square of four stars, is in the east, standing on one corner. It is known as the Great Square of Pegasus. Only the front half of the horse is in the sky, and he’s flying upside down with his neck and head extending to the right from the rightmost star. His galloping front legs extend upward from the top star. Our Anishinaabek native peoples saw a moose here standing upright.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Pegasus at 10 p.m. Chart created using Stellarium.
09/07/2015 – Ephemeris – Small summer constellations
Ephemeris for Labor Day*, Monday, September 7th. The Sun will rise at 7:11. It’ll be up for 12 hours and 56 minutes, setting at 8:08. The Moon, 2 days past last quarter, will rise at 2:47 tomorrow morning.
Located below the eastern edge of the Summer Triangle of three of the brightest stars in the sky, which is overhead in our sky at 10 p.m., is the tiny constellation of Delphinus the dolphin. Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water. The parallelogram itself has the name Job’s Coffin. The origin of this asterism or informal constellation is unknown. Of the dolphin itself: the ancient Greeks told stories of dolphins rescuing shipwrecked sailors. There’s another tiny constellation to the right of Delphinus, Sagitta the arrow a small thin group of 5 stars, which represents Cupid’s dart. Behind Sagitta binoculars will find a little star group called the Coat hanger.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Summer Triangle. Created using Stellarium and The Gimp.
Delphinus, Sagitta and the Coat hanger. Diagram created using Stellarium.
* In the US Labor Day is celebrated on the first Monday in September and is considered the unofficial end of summer. The weather generally agrees. Last week we had a preview of fall weather. This week, except for today has been hot. The outlook for next week is looking decidedly cooler. Most schools in Michigan start the day after Labor Day. and end after June 1st. The unofficial start of summer is Memorial day, the last Monday in May.
09/03/2015 – Ephemeris – Jewels in the shield
Ephemeris for Thursday, September 3rd. The Sun will rise at 7:07. It’ll be up for 13 hours and 9 minutes, setting at 8:16. The Moon, 2 days before last quarter, will rise at 11:26 this evening.
The teapot pattern of stars that is the constellation of Sagittarius lies at the southern end of the Milky Way this evening. It appears that the Milky Way is steam rising from the spout. The area above Sagittarius in the brightest part of the Milky Way is the dim constellation of Scutum the shield. Don’t bother looking for the stars that make up the constellation; what’s important is the star clouds of the Milky Way. Scan this area with binoculars or small telescope for star clusters and nebulae or clouds of gas. In binoculars both clusters and nebulae will appear fuzzy, but a small telescope will tell most of them apart. Even if you’ve never been able to find anything in your telescope, you’ll find something here.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Scutum between Sagittarius below and Aquila above at 10 p.m. September 3, 2015. Created using Stellarium.
How to find the three brightest deep sky wonders around Scutum by star hopping. Created using Stellarium, annotated by myself.
Star hopping is a method to find objects from familiar star patterns. At the top my method to find M11, the wild duck cluster is to locate the three stars at the tail of Aquila the Eagle and follow them to M11. M11 takes a little bigger telescope to resolve. I remember having trouble resolving it is a 5″ telescope. It looks like a triangular cluster with all the stars of the same dimness except one brighter one.
At the bottom of Scutum, I locate that distinctive 5 star group circled. Directly west is M16, the Eagle Nebula and star cluster. The star cluster is easy to spot, the nebula is hard. The Hubble space telescope made the nebula famous in the 1990’s as the Pillars of Creation.
Below and west is M17, the Omega Nebula, or the Swan Nebula. To me it looks like a swan swimming or a check mark of nebulosity. The associated star cluster is much less noticeable.
Happy star hopping.
09/02/2015 – Ephemeris – Planets at either end of the night
Ephemeris for Wednesday, September 2nd. The Sun will rise at 7:06. It’ll be up for 13 hours and 12 minutes, setting at 8:18. The Moon, 3 days before last quarter, will rise at 10:45 this evening.
Lets look for the bright planets for this week. Saturn is alone in the evening sky spotted low in the southwestern sky near the bright star Antares to its lower left. It will set at 11:32 p.m. The rest of the planet action has moved to the morning sky. Mars is now climbing away from the Sun. It’s pretty dim, rising before the start of morning twilight at 4:56 a.m. in the east-northeast. Venus is making a grand appearance, rising at 5:12 a.m. a bit north of east. Much dimmer Mars is to the left and a bit above Venus. Mercury, though in the evening sky is poorly placed for viewing. That won’t be true next month when it enters the morning sky. Jupiter now is too close to the direction of the Sun to be seen.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Saturn with the Zodiacal constellations of Libra, Scorpius and Sagittarius as the Teapot. Created using Stellarium.
What Saturn and its moons might appear like in a telescope at 10 p.m., September 2, 2015. Small telescopes will show only the moon Titan. Created using Stellarium.
Is it a UFO? Is it an airplane’s landing lights? Nope, it’s Venus. Also visible is Mars nearby with the stars and constellations of Winter at 6 a.m. September 3, 2015. Created using Stellarium.
Venus through a telescope – September 3, 2015. Created using Stellarium.
This is a chart showing the sunrise and sunset skies for September 2, 2015 showing the location of the planets and the Moon at that time. Created using my LookingUp program. Click on the image to enlarge.
Note the angle of the ecliptic to the Sun at the morning and evening horizon. It is at a very low angle in the evening. That’s why Mercury, though at a fairly large distance from the Sun (27º) is not really visible in the evening. In the morning the ecliptic rises at a much steeper angle so Venus at 25.5º separation from the Sun is easily visible. The situation will be reversed in 6 months, or right now if you travel south of the equator.
09/01/2015 – Ephemeris – Previewing September – Part 2: Total Lunar Eclipse
Ephemeris for Tuesday, September 1st. The Sun will rise at 7:04. It’ll be up for 13 hours and 15 minutes, setting at 8:19. The Moon, 3 days past full, will rise at 10:07 this evening.
Today in part 2 of the September preview we look ahead at this month’s total lunar eclipse on Sunday evening the 27th. This is the last of four total lunar eclipses in a row that started last year April, continuing last October and this April. Only this past April’s eclipse was visible in clear skies here, but all we could see was the beginning partial phase from here. We will get to see, clouds willing, the whole eclipse between 9 p.m. and 12:30 a.m. Lunar eclipses only can occur at full moon, when the Sun, Earth and Moon are lined up so that the Earth’s shadow falls on the Moon. The Moon will be completely immersed in the Earth’s shadow for over an hour then. You can mark it on your calendars, but I will be reminding you about it all the week before.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The following is my article from September’s newsletter of the Grand Traverse Astronomical Society the Stellar Sentinel. Note as with the above tines, the times here are Eastern Daylight Time.
The Last of a Quartet of Lunar Eclipses
The last of a quartet or tetrad of consecutive total lunar eclipses will occur Sunday night September 27th. The others were either clouded out or started too late for totality to be visible from here. We are hoping for good weather for this one.
Lunar eclipses or eclipses of the Moon, as these events are also called, only occur at full moon when the Earth’s shadow is cast upon the Moon. Unlike a solar eclipse, of which the partial phases are dangerous to gaze upon without special protection, a lunar eclipse is perfectly safe to view throughout.
How lunar eclipses occur. Credit NASA/Fred Espenak.
There are three kinds of lunar eclipses or phases of lunar eclipses: penumbral, partial, and total. A total eclipse passes through all three phases. In the penumbra the Sun’s light is increasingly cut off from the outside to the inside of the shadow called the umbra, where all direct sunlight is cut off. Depending on the path of the Moon, it can cut through only the penumbra, in which the eclipse is barely noticeable, a penumbral eclipse; pass only partially through the umbra, a partial eclipse; or immerse completely in the umbra to produce a total eclipse.
Lunar eclipses are easiest to see, because one only has to be on the night side of the Earth to see it. In a solar eclipse, the Moon’s shadow is too small to cover the earth, since it’s only a quarter the size of the Earth, so one has to be in a band a few thousand miles wide to spot the partial phase and has to be in a very narrow couple hundred mile wide path to see the brief totality. We’ll revisit this in 2016 in preparation for the country spanning total solar eclipse of August 21, 2016.
Eclipses, both lunar and solar occur in seasons nearly 6 months apart, which usually have one of each two weeks apart. Occasionally with a central eclipse of one to have two of the other two weeks before and two weeks after.
The reason for this is because the Earth and Moon’s orbits are tilted at about a 5° angle, and the point where they cross, 180° apart is slowly rotating clockwise. This gives us two eclipse seasons a year that slowly move earlier in the calendar. It is only when the Sun is near where the orbital planes cross that we have a chance for an eclipse, otherwise the Moon is too far north or south.
After this eclipse, the next total lunar eclipse will be January 21, 2019. However the Moon will set while in totality for us on that one.
If you’d like to explore eclipses further, check out this NASA website: http://eclipse.gsfc.nasa.gov/eclipse.html.
The eclipse occurs on the 28th for Universal Time. It’s the evening of the 27th for us. The Moon travels through the Earth’s shadow from right to left. What are seen are points of contact with the shadow and mid-eclipse. From Five Millennium Canon of Lunar Eclipses (Espenak & Meeus) NASA.
Contact times are labeled P1, U1, U2, U3, U4, and P4. P2 and P3 are omitted because they are synonymous with U1 and U4 respectively:
- P1 – 8:11:47 p.m. Enter the penumbra (unseen). By about 8:30 the duskiness on the left edge of the moon will start to be noticeable.
- U1 – 9:07:11 p.m. Enter the umbra (partial eclipse begins).
- U2 – 10:11:10 p.m. Totality begins.
- Mid eclipse 10:48:17 p.m.
- U3 – 11:23:05 p.m. Totality ends, egress partial phase begins.
- U4 – 12:27:03 a.m. Partial phase ends. The Moon’s upper right edge should appear dusky for the next half hour or so.
- P4 – 1:22:27 a.m. Penumbral phase ends (unseen).
Note: The duskiness of the penumbral phase of the eclipse can be enhanced by viewing through sunglasses.
During the total phase, light leaks in around the Earth due to the bending of light in the Earth’s atmosphere, so the Moon is illuminated by the collective sunrises and sunsets around the globe. This usually gives the Moon a coppery hue, that some are now calling a blood moon. Occasionally, due to volcanic eruptions the Moon can become very dark.
This full moon is also the Harvest Moon and for those who care, a supermoon, it having reached perigee earlier that day.
Weather permitting there will be two GTAS venues in northern lower Michigan to view this eclipse. The first will be the Northwestern Michigan College Rogers Observatory, south of Traverse City, MI. The second will be at the Sleeping Bear Dunes National Lakeshore at Platte River Point at the end of Lake Michigan Road off M22. These sites will be open for the visible parts of the eclipse from 9 to midnight.
Of course the eclipse can be seen from your yard with no optical aide whatsoever.
The partially eclipsed Moon setting through a thin clouds and the neighbor’s swing set at 7:09 EDT April 4, 2015. Taken with a Motorola Droid Razr phone through 10X50 binoculars. Credit: Bob Moler.
08/31/2015 – Ephemeris – Previewing the skies of September – Part 1
Ephemeris for Monday, August 31st. The Sun will rise at 7:03. It’ll be up for 13 hours and 18 minutes, setting at 8:21. The Moon, 2 days past full, will rise at 9:31 this evening.
Let’s look forward to the skies of September. The sun will moving at its greatest speed in its retreat to the south. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 15 minutes tomorrow the 1st. to 11 hours 46 minutes on the 30th. The altitude of the sun above the southern horizon at local noon will be 54 degrees tomorrow, and will descend to 42 degrees on the 30th. The Straits area will see the sun a degree lower. The season of summer is getting short, so enjoy it while you can. Summer ends and autumn begins at 4:20 a.m. on September 23rd. Saturn is setting before midnight now, but Venus and Mars are appearing in the morning sky soon. Tomorrow we’ll look at September’s lunar eclipse.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location
Addendum
Star Chart for September 2015. Created using my LookingUp program.
The planets and stars are plotted for the 15th at 10 p.m. EDT. That is chart time. Note, Traverse City is located 1 hour 45 minutes behind our time meridian. To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
Evening astronomical twilight ends at 10:04 p.m. EDT on August 1st, decreasing to 9:02 p.m. EDT on the 30th..
Morning astronomical twilight starts at 5:19 a.m. EDT on August 1st, and increasing to 6:01 a.m. EDT on the 30th.
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.
The green pointer from the Big Dipper is:
- Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
- Follow the arc of the Big Dipper’s handle to Arcturus.
- The Summer Triangle is shown in red.
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 on a 24 hour clock. Some additions made to aid clarity.
Conjunctions like the Mars-Regulus: 0.8° N means Regulus will appear 0.8° north of Mars.
| Sep | 01 | Tu | Venus: 25° W | |
| 04 | Fr | 05:59 | Mercury Elongation: 27.1° E | |
| 05 | Sa | 01:09 | Moon-Aldebaran: 0.6° S Occultation?* | |
| 05 | Sa | 05:54 | Last Quarter | |
| 06 | Su | 13:06 | Moon North Dec.: 18.2° N | |
| 10 | Th | 01:53 | Moon-Venus: 2.9° S | |
| 13 | Su | 02:41 | New Moon | |
| 13 | Su | 02:55 | Partial Solar Eclipse (Southern tip of Africa to Antarctica) | |
| 14 | Mo | 00:38 | Moon Ascending Node | |
| 14 | Mo | 07:28 | Moon Apogee: 406500 km | |
| 18 | Fr | 22:54 | Moon-Saturn: 3.1° S | |
| 21 | Mo | 04:59 | First Quarter | |
| 21 | Mo | 08:02 | Moon South Dec.: 18.1° S | |
| 23 | We | 04:20 | Autumnal Equinox | |
| 24 | Th | 15:38 | Mars-Regulus: 0.8° N | |
| 27 | Su | 17:04 | Moon Descending Node | |
| 27 | Su | 21:46 | Moon Perigee: 356900 km – Super moon | |
| 27 | Su | 22:48 | Total Lunar Eclipse | |
| 27 | Su | 22:50 | Full Moon – Harvest Moon | |
| 30 | We | 10:36 | Mercury Inferior Conjunction with the Sun | |
| Oct | 01 | Th | Venus: 43.6° W |
* For the Grand Traverse Region the Moon will rise at 12:10 a.m. occulting Aldebaran. Aldebaran will appear at the Moon’s unilluminated top right edge at approximately 12:40 a.m.
Note: All lunar conjunctions in the table above are geocentric. Double check with a program like Stellarium to check on the position of the body with respect to the moon for your location.
