Archive
10/08/10 – Ephemeris – Local World Space Week event
Friday, October 8th. The sun will rise at 7:48. It’ll be up for 11 hours and 21 minutes, setting at 7:10. The moon, 1 day past new, will set at 7:16 this evening.
This is World Space Week which was celebrated last year by a star party at the White House. This year the Grand Traverse Astronomical Society will join societies, planetariums, and observatories around the world. The local society’s contribution is a star party tonight near the Open Space on the bay front in Traverse City. The grassy expanse where the old light and power generators stood appears dark enough for our purposes. Society members will be out tonight from about 8 p,.m. If it’s clear. If not we’ll postpone it to Saturday night. The giant planet Jupiter will be the featured attraction. This is a new venue for the society so we’ll test just how dark it is. For more information go to worldspaceweek.org. Dress warmly, Clear nights are cold this time of year.
Times are for the Grand Traverse Area of Northern Michigan, USA.
10/07/10 – Ephemeris – The star Fomalhaut
Thursday, October 7th. The sun will rise at 7:47. It’ll be up for 11 hours and 24 minutes, setting at 7:12. The moon is new today, and won’t be visible.
There’s a bright star that appears for only seven and a half hours a night on autumn evenings. It’s appearance, low in the south, is a clear indication of the autumn season. At 9 p.m. tonight it’s low in the southeast. The star’s name is Fomalhaut, which means fish’s mouth. That fits because it’s in the constellation of Piscis Austrinus, the southern fish. At our latitude it’s the fish that got away, because Fomalhaut appears to be quite alone. The dimness of the constellation’s other stars and location close to the horizon make the fainter stars hard to spot. They would be overhead in Australia. The earth’s thick atmosphere near the horizon reduces the stars brightness by a factor of two or more, so Fomalhaut appears to keep a lonely vigil in the south.
Times are for the Grand Traverse Area of Northern Michigan, USA.
10/06/10 – Ephemeris – The planets this week
Wednesday, October 6th. The sun will rise at 7:46. It’ll be up for 11 hours and 27 minutes, setting at 7:13. The moon, 1 day before new, will rise at 7:42 tomorrow morning.
Lets take a look at the bright planets for this week. Venus and Mars are very low in the twilight. Venus is the brightest. It’s 32.1 million miles away and slowly approaching, and appears as a thin crescent. If you can find it. It will set at 7:41 p.m. Mars, though appearing farther from the sun, is too dim to be spotted in the bright twilight. The planet Jupiter is up at sunset and will move due south at 12:29 a.m.. It is very bright in the southeastern sky, and the brightest starlight object in the sky. It’s located in Pisces this year and will set at 6:19 a.m. Comet Hartley 2 may be just visible in binoculars as a fuzzy spot just right of the bottom of the W shape of the constellation Cassiopeia in the evening now.
Times are for the Grand Traverse Area of Northern Michigan, USA.
10/05/10 – Ephemeris – The constellation Capricornus
Tuesday, October 5th. The sun will rise at 7:45. It’ll be up for 11 hours and 30 minutes, setting at 7:15. The moon, 2 days before new, will rise at 6:22 tomorrow morning.
2000 years ago the southernmost of the constellations of the zodiac was Capricornus the water goat. That’s why the latitude on the earth where the sun is overhead on the winter solstice is called the Tropic of Capricorn. Not any more, Sagittarius, one constellation west, has that honor today. Actually Capricornus does need the press. It’s large, but made up of dim stars. To me it looks like a 45 degree isosceles triangle, long side up, but which all the sides are sagging. The constellation is found low in the south at 10 p.m. and tilted a bit from the upper right to the lower left. The image that is supposed to be represented by the stars is that of a goat whose hind quarters are replaced by a fish’s tail, not a mermaid but a mer-goat.
*Times are for the Grand Traverse Area of Northern Michigan, USA.
10/04/10 – Ephemeris – Comet Hartley 2
Monday, October 4th. The sun will rise at 7:43. It’ll be up for 11 hours and 33 minutes, setting at 7:17. The moon, 3 days before new, will rise at 5:02 tomorrow morning.
Comet 103P/Hartley 2 is visible all night, but it’s visible only in binoculars or a small telescope It’s cruising past the W shaped constellation of Cassiopeia in the northeast in the evening. Looking at the W in the evening it’s standing on one end, and looks like the number 3. The comet is moving down just to the right of it. Since it is seen against the Milky Way there are some other fuzzy spots to confuse you. The comet will stay fuzzy in a telescope. Discovered in 1986 by Malcolm Hartley in Australia, the comet has a 6 and a half year orbit of the sun. It will be closest to the earth on October 20th. The Deep Impact spacecraft renamed EPOXI will pass close to the half mile diameter nucleus on November 4th.
Times are for the Grand Traverse Area of Northern Michigan, USA.
10/01/10 – Ephemeris GTAS activities this weekend
Friday, October 1st. The sun will rise at 7:40. It’ll be up for 11 hours and 42 minutes, setting at 7:23. The moon, 1 day past last quarter, will rise at 1:10 tomorrow morning.
This evening the Grand Traverse Astronomical Society will meet at 8 p.m. at Northwestern Michigan College’s Rogers Observatory. Special guest Walter Hoegy, retired physicist from NASA’s Goddard Space Flight Center will provide the program: “Climate Studies in the Arctic and a look at the Sun”. Tomorrow night starting at 8 p.m. there will be a Public Viewing Night at the observatory. This is that last shot at viewing the wonders of the southern part of the Milky Way with its bright nebulae where stars are being formed and star clusters. Bright Jupiter and maybe even Uranus will also be featured.. The observatory is located south of Traverse City on Birmley Road between Garfield and Keystone roads.
Times are for the Grand Traverse Area of Northern Michigan, USA.
09/30/10 – Ephemeris – October Preview
Thursday, September 30th.* The sun will rise at 7:39. It’ll be up for 11 hours and 45 minutes, setting at 7:24. The moon, at last quarter today, will rise at 11:59 this evening.
Let’s look at the skies for the month of October. The sun will still moving south rapidly. Daylight hours in the Interlochen/Traverse City area and will drop from 11 hours and 42 minutes tomorrow to 10 hours, 14 minutes at months end.. The altitude of the sun above the southern horizon at local noon will be 42 degrees tomorrow, and will descend to 31 degrees on Halloween, also in the Interlochen area. The Straits area will have the sun a degree lower. Local noon, when the sun is due south will be about 1:30 p.m. in Interlochen. Sunrise times will increase all the way to 8:18 a.m. in Interlochen on the 31st. Sunset times will decrease from 7:23 p.m. tomorrow to 6:32 when the trick or treaters haunt our neighborhoods.
Times are for the Grand Traverse Area of Northern Michigan, USA.
09/29/10 – Ephemeris – Planets this week
Wednesday, September 29th. The sun will rise at 7:37. It’ll be up for 11 hours and 48 minutes, setting at 7:26. The moon, 1 day before last quarter, will rise at 10:55 this evening.
Lets take a look at the bright planets for this week. Venus and Mars are very low in the twilight. Venus is the brightest. It’s 36 million miles away and slowly approaching, and appears as a thin crescent. It will set at 8:09 p.m. Mars is above, left of Venus, and much dimmer. I doubt if you could spot it. The planet Jupiter is up at sunset and will move due south at 2:59 a.m.. It’s located in Pisces this year and will set at 6:51 a.m. Mercury is difficult to spot low in the east before sunrise. It will rise tomorrow morning at 6:30 a.m. Mercury is visible in the morning twilight in the east. 6:45 to 7:10 a.m. is the best time to spot it. Comet Hartley 2 may be just visible in binoculars as a fuzzy spot just right of the W shape of the constellation Cassiopeia in the evening now.
Times are for the Grand Traverse Area of Northern Michigan, USA.
9/28/10 – Ephemeris – Venus
Tuesday, September 28th. The sun will rise at 7:36. It’ll be up for 11 hours and 51 minutes, setting at 7:28. The moon, 2 days before last quarter, will rise at 10:00 this evening.
Venus, if you can catch it before it sets at 8:13 p.m. is a very thin crescent. Venus is visible as a crescent even in binoculars now. A very tiny and thin one. Though the planet Venus is very close to the earth now, it is difficult to see. It is low in the sky, setting very soon after the sun. Being low in the sky, telescopes cannot see good detail on its surface, if we could see it at all, which we can’t. Venus is cloud covered. Its dense atmosphere of mostly carbon dioxide is covered by layers of sulfuric acid clouds. Two decades ago the Magellan spacecraft orbited the planet with radar and mapped the hellish surface. In roughly the same period the Soviets landed probes on its surface to see its barren landscape lit by a dim reddish sun.
Times are for the Grand Traverse Area of Northern Michigan, USA.
9/27/10 – Ephemeris – Extrasolar Planets
Monday, September 27th.* The sun will rise at 7:35. It’ll be up for 11 hours and 55 minutes, setting at 7:30. The moon, 3 days before last quarter, will rise at 9:16 this evening.
Astronomers have been discovering planets around other stars for the last 15 years. These planets tend to be as massive as Jupiter or greater, and tend to be very close to their parent stars. The orbital period of these planets tend to be the matter of days. Over the years we had been comfortable with how the planets are located in our solar system: Inner rocky worlds and farther out large gaseous planets. Now, what we are finding is in part the result of the techniques we use, which are most sensitive to large planets orbiting close to their stars. Currently aloft is a spacecraft called Kepler that we hope is also sensitive to small planets orbiting farther from their stars by recording them passing in front of their stars.
*Times are for the Grand Traverse Area of Northern Michigan, USA.
