Archive
09/21/2012 – Ephemeris – International Observe the Moon Night
Ephemeris for Friday, September 21st. The sun will rise at 7:28. It’ll be up for 12 hours and 11 minutes, setting at 7:40. The moon, 1 day before first quarter, will set at 11:26 this evening.
Tomorrow evening the Grand Traverse Astronomical Society will host a star party at Northwestern Michigan College’s Rogers Observatory starting at 9 p.m. It is also the International Observe the Moon Night. A first quarter moon is what I consider the best of all moons to observe. But that’s just my opinion. It shows a great number of craters near the terminator, the sunrise line that cuts the moon in two at first quarter. Also the moon won’t be too bright to mask some of the wonders of the summer Milky way. The observatory is located south of Traverse City on Birmley Road, between Garfield and Keystone roads. Speaking of summer, It will end at 10:49 a.m. When autumn will begin as the sun passes the celestial equator heading south.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
update
Members of the GTAS will also be stationed in downtown Traverse City on Front St. near the State Theater. Thats only if its clear.
09/20/2012 – Ephemeris – Tides and the moon
Ephemeris for Thursday, September 20th. The sun will rise at 7:27. It’ll be up for 12 hours and 14 minutes, setting at 7:42. The moon, 2 days before first quarter, will set at 10:29 this evening.
The moon and the earth gravitationally attract each other. And the moon raises tides in the earth itself and its oceans. The earth’s tides on the mass of the moon has slowed its rotation so it continually shows the earth the same face. The moon, only one 81st the mass of the earth hasn’t been as successful at slowing the earth’s rotation. It caused the world’s timekeepers to add one second this June to the time stream after several years to match our atomic clocks to the earth’s rotation. The most noticeable effects of the moons tidal force is the tides in the earth’s oceans. The highest tides are when the sun and moon are in line at new and full moon. Small bodies of water like the Great Lakes don’t have luni-solar tides.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Note
I can’t explain much about tides in one minute. Here I’m not explaining the force, but am explaining that it affects the solid bodies as well as the oceans on the earth.
09/19/2012 – Ephemeris – Where are the bright planets this week?
Ephemeris for Wednesday, September 19th. The sun will rise at 7:26. It’ll be up for 12 hours and 18 minutes, setting at 7:44. The moon, 3 days before first quarter, will set at 9:40 this evening.
Let’s see how many bright planets we can find this week. Mars and Saturn now set too close to the sun to be easily seen in the evening sky. Both are in the west southwestern sky and very low in twilight. Saturn sets at 9:02 p.m., while Mars sets at 9:33. The planetary action moves to later in the evening and the morning. Jupiter, will rise at 11:07 p.m. in the east northeast. It is located in the constellation of Taurus. The last bright planet of the night is the morning star Venus which will rise at 3:45 a.m. also in the east northeast. Venus is now moving through Cancer towards Leo. The planets Venus and Jupiter and the winter constellations are a great sight for early risers.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Mars, the moon and Saturn at 8:30 p.m. on September 19, 2012. Created using Stellarium.
Note that the sky will be brighter than this. The moon will be a thin crescent, and not at all bright. tell me if you can spot these guys.
Jupiter, nearly an hour after rising – midnight September 20, 2012. Created using Stellarium.
Jupiter and Venus among the star of winter at 6 a.m. on September 20, 2012. Created using Stellarium.
On a personal note
This would have been my mother’s 100th birthday. She passed away 34 years ago. It is she who first taught me the constellations.
09/18/2012 – Ephemeris – The center of the Milky Way
Ephemeris for Tuesday, September 18th. The sun will rise at 7:25. It’ll be up for 12 hours and 21 minutes, setting at 7:46. The moon, 3 days past new, will set at 8:58 this evening.
Look to the south southwest at 10 p.m. At the constellation of Sagittarius, which looks like a teapot. It’s located at the south end of the Milky Way. Just off the spout of the teapot lies, beyond the clouds of stars, gas and dust, at a distance of about 27,000 light years, the center of the Milky Way. The center contains a 4 million sun mass black hole with a bevy of stars orbiting around it like planets orbit the sun. Black holes are so massive that, nothing, not even light can escape their gravity. Lots of energy is released by matter falling in to a black hole. Currently our Milky Way’s black hole is quiet, nothing of note is falling in. However there is a cloud of gas and dust approaching the black hole, so its quiet phase may end next year.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Location of the center of the Milky Way and the Teapot of Sagittarius.
While the actual center of the galaxy cannot be seen in optical wavelengths it is visible in radio, infrared and x-rays. The black hole at the center of the Milky Way is designated Sagittarius A* (pronounced Sagittarius A Star). Check it out in Wikipedia and other sources.
09/17/2012 – Ephemeris – Cygnus and the search for exo-planets
Ephemeris for Monday, September 17th. The sun will rise at 7:24. It’ll be up for 12 hours and 24 minutes, setting at 7:48. The moon, 2 days past new, will set at 8:21 this evening.
Nearly overhead at 10 p..m. is the constellation Cygnus the swan. The bright star Deneb is at the tail of this flying swan with its wings outstretched, flying south through the Milky Way. Cygnus is located at a point in the Milky Way in the direction the sun’s orbiting the center of the Milky Way. That is the approximate direction the Kepler spacecraft is staring. Launched in 2009 the Kepler spacecraft has been slowly drifting away from the earth in a trailing orbit of the sun. It is monitoring over 100,000 stars continuously looking for transits of planets across their stars. So far some 2300 suspects have been found. They have to be confirmed by ground based telescopes before being officially cataloged. So far close in planets to their stars have been discovered.
Addendum
Kepler Spacecraft. Credit NASA.
Click image to enlarge.
Kepler field of view. Credit C. Roberts, NASA.
Click image to enlarge.
Link to Kepler’s home page: http://kepler.nasa.gov/
09/14/2012 – Ephemeris – The Leland Heritage Celebration at Fish Town
Ephemeris for Friday, September 14th. The sun will rise at 7:20. It’ll be up for 12 hours and 33 minutes, setting at 7:54. The moon, 1 day before new, will rise at 6:53 tomorrow morning.
Tomorrow the 15th the Grand Traverse Astronomical Society will participate in the Leland Heritage Celebration to safely view the sun, which is now very active. The event will take place in and around historic Fish Town at the harbor. If its clear we will have out Lunt solar telescope to view the sun’s chromosphere, the layer of hydrogen above the bright ball of the sun we see with normal solar filters. In the chromosphere are seen solar flares when they occur, huge jets of hydrogen gas called prominences when seen sticking out the side of the sun and filaments when seen against the sun. Society members will be on hand to answer questions about the heavens and telescopes. Times for this event are 10 a.m to 3 p.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
GTAS telescopes at Leland Heritage Celebration in 2011.
That was before the GTAS acquired the Lunt Hydrogen α (alpha ) Solar Telescope.
09/13/2012 – Ephemeris – The Great Rift
Ephemeris for Thursday, September 13th. The sun will rise at 7:19. It’ll be up for 12 hours and 36 minutes, setting at 7:55. The moon, 2 days before new, will rise at 5:43 tomorrow morning.
High overhead the Milky Way is seen passing through the Summer Triangle of three bright stars. Here we find the Milky Way split into two sections. The split starts in the constellation of Cygnus the Swan or Northern Cross nearly overhead and heads southward. The western part of the Milky Way ends southwest of the Aquila the eagle. This dark dividing feature is called the Great Rift. The rift is a great series of clouds obscures the light of the stars behind it. It appears to be about 300 light years away and obscures the light of the stars of the next spiral arm in. It may contain the mass of a million suns. Dust clouds like this are a prominent features of spiral galaxies, like the Milky Way.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Great Rift in the Milky Way. Created using Stellarium.
P.S.
Semper Fi
My grandson Chris the Marine celebrates his 22nd birthday today. He’s in the desert today in the US. Beats Afghanistan where he was last year at this time.
09/12/2012 – Ephemeris – Where are the bright planets this week?
Ephemeris for Wednesday, September 12th. The sun will rise at 7:18. It’ll be up for 12 hours and 39 minutes, setting at 7:57. The moon, 3 days before new, will rise at 4:34 tomorrow morning.
Let’s see how many bright planets we can find this week. Mars, Saturn and the star Spica make an elongated triangle in the west southwest in twilight after sunset. Mars is on the left with Saturn on the upper right and Spica below. It may take binoculars to spot them. Spica will set first at 8:57 followed by Saturn at 9:28 and Mars at 9:51. It’s getting harder and harder to spot these guys each evening. The morning sky features the two brightest planets: Jupiter, will actually rise before midnight at which will rise at 11:29 p.m. in the east northeast and Venus, which will rise at 3:33 a.m. also in the east northeast. Jupiter is near the head of Taurus the bull, while Venus is in Cancer. The moon will be near it tomorrow morning, as it is this morning.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus and the moon on September 12, at 5:30 a.m. Created using Stellarium.
Planets Mars, Saturn and the star Spica in twilight at 8:30 p.m. on September 12, 2012. Created using Stellarium.
The planets Venus and Jupiter among the winter stars visible ay 5:30 a.m. September 13, 2012. Created using Stellarium.
09/11/2012 – Ephemeris – The constellation Sagittarius the archer
Ephemeris for Tuesday, September 11th. The sun will rise at 7:17. It’ll be up for 12 hours and 42 minutes, setting at 7:59. The moon, 3 days past last quarter, will rise at 3:28 tomorrow morning.
Low in the south at 10 p.m. lies the constellation of Sagittarius. The name means archer, but this isn’t just any old fellow with a bow and arrow. It’s a centaur with a bow and arrow. These half man half horse creatures were a rowdy bunch; kind of the ancient Greek counterpart of a motorcycle gang. The one exception is this centaur, Chiron by name. He was highly educated, and learned medicine from the great physician Aesculapius, whom we see in the sky to the upper right as the constellation Ophiuchus. His drawn bow and arrow can also be seen in the stars here, pointing to Scorpius the scorpion’s heart. If it’s hard seeing a Centaur here don’t be disappointed. To most of us the constellation looks like a stout little teapot.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Sagittarius and the Milky Way September 11, 2012 10 p.m. Created using Stellarium.
09/10/2012 – Ephemeris – The constellation Cepheus the king
Ephemeris for Monday, September 10th. The sun will rise at 7:16. It’ll be up for 12 hours and 45 minutes, setting at 8:01. The moon, 2 days past last quarter, will rise at 2:25 tomorrow morning.
The stars of autumn are taking over the eastern evening sky as the equinox approaches. Looking to the northeastern sky at 10 p.m. we find the W shaped constellation of Cassiopeia the queen. It is opposite the pole star Polaris from the Big Dipper. Above Cassiopeia is a dim church steeple shaped constellation of Cepheus the king. The steeple is toppled to the left. It also lies on the line between the bright star Deneb, the northeastern most star of the Summer Triangle and Polaris. Cepheus is a king and the husband of the more notorious Cassiopeia. The Milky Way flows through a corner of Cepheus. One of its stars is Delta Cephei is the first of a type of variable star that have allowed us to measure distances to the galaxies.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The constellation Cepheus at 10 p.m. September 10th. Created using Stellarium.
Click image to enlarge.
