Bob’s Ephemeris Blog

The Grand Traverse Astronomical Society will host has hosted a eclipse watch at Northwestern Michigan College’s Rogers Observatory. It will be open for the event starting 4:30 a.m. August 28th but only if it’s clear. More details below.

7:00 a.m. 8/28/07:

This is the last post. We had maybe a dozen people off and on at the observatory. The sky deteriorated from my last post. We had lightning to the west and dense clouds. I found a web feed from the University of North Dakota. So we watched it that way.

Next lunar eclipse is February 20th in the evening. Hope the weather’s nicer then.

4:45 a.m. 8/28/07:

Hey, it may be clearing up! Come on out.

4:00 a.m. 8/28/07:

It’s not looking good at all folks. There are no holes on the clouds. I’ll head out to the observatory anyway, since I’m already up. But the only eclipse visible will be computer simulations and what we can pick up on the Internet. Next update will be from the observatory.

3:15 a.m. 8/28/07:

The cloud cover is pretty solid, with very small and occasional holes. Satellite imagery isn’t offering much hope either. The cloud flow is now more from the west. I don’t think we’ll get rained on before sunrise, but it’s not looking good for viewing, gang. Another report at 4 a.m.

11 p.m. 8/27/07:

The mostly cloudy part of the forecast has come true. Bits of the moon appear at odd intervals in the mostly overcast sky. I’m hoping that there’s a slot of clear sky coming from the southwest. The infrared satellite pictures are hard to interpret. The flow of the clouds seems to be from the southwest. I’m heading for the sack. The next update will be shortly after 3 a.m.

8:45 p.m. 8/27/07:

The National Weather Service forecast for tonight is for mostly cloudy skies. Right now we have clearing skies to the west, which corroborated by the radar image at this hour. But there’s big clouds farther to the west. The question is: “Will we get to see the eclipse before the clouds arrive? Stay tuned. It’s too close to call. Of course you don’t need to go to the observatory to see it. It’s perfectly visible to the unaided eye or binoculars.

Check for yourself:

• Clear Sky Clock from Attilla Danko
• NWS Traverse City Forecast.
• Gaylord, MI Weather Radar.
• Satellite Infrared Loop.
• Canadian based Infrared Satellite (Michigan shows best in the Eastern Canada view)

There will be a total eclipse of the moon visible, or about half of a total eclipse from northern Michigan Tuesday morning, August 28th. Of course it all depends on the clouds or more importantly the lack thereof. The upper part of the moon will have a duskiness to it by 4:30 a.m. Here’s the timing of the event for the Traverse City/Interlochen area:

Moon enters umbra: 4:51 a.m.
Moon enters totality: 5:52 a.m.
Middle of eclipse: 6:37 a.m.
Sunrise at Interlochen/Traverse City: 7:00 a.m.
Moon set at Interlochen/Traverse City: 7:04 a.m.
Moon leaves totality: 7:22 a.m.
Moon leaves umbra: 8:24 a.m.

The times are for Eastern Daylight Time. Subtract 1 hour from the eclipse times for CDT, 2 hours for MDT and 3 hours for PDT. Sunrise and moon set times will vary a bit from the times given here based on your position relative to your time meridian, and a bit on your latitude. Check your local sources, or check the Ephemeris calendar page to access an Internet source.

With sunrise a bit more than an hour away from the beginning of totality, the sky will be getting brighter and the moon may disappear soon after if the earth’s shadow is too dark for the brightening twilight.

Click image for an AVI animation created using the free open source program Stellarium. The link will be active until after the eclipse. The NASA data for this eclipse is found here and here.

Northwestern Michigan College’s Rogers Observatory is located south of Traverse City on Birmley Road between Garfield and Keystone roads. You can reach Birmley by going south on Garfield two traffic lights south of South Airport road. Turn right, and go about 3/4 mile. The observatory road is to the left.

Tags: Events, Observing by Bob Moler
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This year again there is a Mars email hoax. It’s the same one that’s been going around, with Mars appearing as big as the moon on August 27th. Nope. Nada. Ain’t gonna happen. It’s a distorted reference to Mars’ close approach in 2003 on August 27th of that year. Still, for those who saw it, it’s telescopic image was still small. This year Mars will be at it’s closest on December 19th, at just under 55 million miles away, over 20 million miles farther than in 2003. Below is an email my daughter got in 2005. I haven’t seen this year’s email yet, though I’ve been asked about reports of it, so I don’t know if these guys have any originality.

The data was fine for the year 2003, despite the misleading use of font sizes, colors and spacing for the big central clause. The sentence was correct for 2003: “At a modest 75-power magnification Mars will look as large as the full moon to the naked eye.”

This year, on December 19th you will need to use 113 power to produce the same result, however don’t expect to see much detail especially if you have a cheap department store telescope.

Above is Scott Anttila’s best digital image of Mars from August 25, 2003.  It ain’t gonna look that good this December.

Tags: Scott Anttila, Non-events, Hoaxes by Bob Moler
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Just before dawn we might spot the start of a rare meteor shower called the Aurigids. It’s unusual because it’s related to a comet with a 1,995 year orbit of the sun. The comet came near the sun in 83 BC. It next came through in 1911, when it was discovered by Carl Kiess. The stream of debris from 83 BC is still passing the sun, and the earth’s orbit. The ribbon of debris is undulating, affected by the gravitation of the sun and all the planets. This year the earth is expected to clip the edge of the stream as it has done in the past in 1935, 1986, and 1994. A 2 hour shower of very bright meteors is expected, centered at 7:36 a.m., Eastern Daylight Time a bit late for us. However it might be profitable to check it out. They’re expected to be really bright. The radiant for the shower is just east of the pentagon of the constellation of Auriga.

More information can be found here with maps and all the all the particulars. Folks on the west coast of North America and Hawaii will get the best views.

Tags: Events, Observing by Bob Moler
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There will be a total eclipse of the moon visible, or about half of a total eclipse from northern Michigan Tuesday morning, August 28th. Of course it all depends on the clouds or more importantly the lack thereof. The upper part of the moon will have a duskiness to it by 4:30 a.m. Here’s the timing of the event for the Traverse City/Interlochen area:

Moon enters umbra: 4:51 a.m.
Moon enters totality: 5:52 a.m.
Middle of eclipse: 6:37 a.m.
Sunrise at Interlochen/Traverse City: 7:00 a.m.
Moon set at Interlochen/Traverse City: 7:04 a.m.
Moon leaves totality: 7:22 a.m.
Moon leaves umbra: 8:24 a.m.

The times are for Eastern Daylight Time. Subtract 1 hour from the eclipse times for CDT, 2 hours for MDT and 3 hours for PDT. Sunrise and moon set times will vary a bit from the times given here based on your position relative to your time meridian, and a bit on your latitude. Check your local sources, or check the Ephemeris calendar page to access an Internet source.

With sunrise a bit more than an hour away from the beginning of totality, the sky will be getting brighter and the moon may disappear soon after if the earth’s shadow is too dark for the brightening twilight.

Click image for an AVI animation created using the free open source program Stellarium. The link will be active until after the eclipse. The NASA data for this eclipse is found here and here.

The Grand Traverse Astronomical Society will host a eclipse watch at Northwestern Michigan College’s Rogers Observatory will be open for the event starting 4:30 but only if it’s clear. Check this Blog for the latest status on whether the weather will permit the observatory to be opened.

When’s the next eclipse?

This has been a year of total lunar eclipses and partial solar eclipses. This happens from time to time. The March total eclipse was clouded out for the Traverse City area. The string of total lunar eclipses will extend to the next eclipse season to a total eclipse of February 20th, in the evening, once again visible from here. Eclipse seasons occur about every 5 months 3 weeks, and last nearly a month. There are at least two eclipses every season, a solar and a lunar eclipse of some sort. Occasionally there can be two partial solar eclipses two weeks prior and after a central total lunar eclipse. As with all eclipses you have to be at the right place and time to see them.

Tags: Events, Observing by Bob Moler
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1 a.m. Saw some bright meteors tonight. Not all of them were Perseids. Two bright GREEN meteors passed slowly through Andromeda and Pegasus in the last hour were spectacular, especially the first through Andromeda. They could be Alpha Capricornids. There was a really brilliant Perseid earlier that lighted up the ground as I was facing away at the time. I turned around to see a fading train that lated over 10 seconds to the unaided eye.

2 a.m. More meteors are being spotted. No really bright this past hour. I’ve been out of action for a quarter of that time. It’s depressing to see Fomalhaut up reminding me that summer will soon end. The Teapot of Sagittarius is pouring itself on the southwestern horizon, only it’s handle now visible. Mars is up, so soon I’ll have to take a look at it.

3 a.m. The pointer stars of the Big Dipper are just about pointing straight up towards Polaris. Saw one bright Perseid leaving a momentary train. Just saw anouther bright one as I write this. And another. Maybe things are picking up!

4 a.m. It’s dropped below 60 degrees. The sky, to me at least, seems a bit brighter and the stars a bit dimmer. I wonder if some cirrus is passing overhead. The IR satellite doesn’t appear to show anything. Saw several really bright Perseids. We now start the last 45 minutes before astronomical twilight starts. I may have glimpsed the space station low in the NW just before it entered the earth’s shadow. I forgot whether it was this or last hour. I’m out of film, so I’ll just lie down and enjoy the show.

5 a.m. Astronomical twilight has started, though no discernible change has occurred in the sky. That’s because of the sky glow from Traverse City 5 miles to the east of me. Had some nice bright meteors, though lying down I had a hard time keeping my eyes open. Orion is now completely up now, so I’ll get a look at M42 before I hang it up. I’ll have an update after I get some sleep.

UPDATE: I cleaned up the posts above. The picture below is my setup. I moved about 200′ south of my house and about 15′ below it. My property falls off to the south. This got me away from most stray light. I ran a power cord down there for the laptop and the radio. I still was in contact with the house wireless router so I could blog.  In the background is my 11″ Dobsonian.  Yes, it’s on a slight angle.  The spot isn’t quite level.  Also in the background is my hammock.   Out of the picture to the far left and behind is the  camera tacking mount.

Below is my tracking mount with camera,  hoping for a good meteor shot.  It’s been a long drought.

Tags: Events, Observing, Real time by Bob Moler
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This weekend, culminating on Monday morning, we’ll be able to see the Perseid meteor shower all night at our latitude (~45 degrees north). The meteor photograph below is my one and only good shot at a bright Perseid. It was taken over 30 years ago.

The meteor shower peak is expected to be at 9 hours UT. That’s 5 a.m. EDT at the start of morning twilight Monday morning the 13th. This is a pretty steady annual shower, caused when the earth passes through a stream of debris from Comet 109P/Swift/Tuttle. The designation 109P means it is the 109th discovered, or recorded, periodic comet, that is it returns at definite intervals, once thought to be 120 years. The comet was first discovered in 1862, It didn’t return in 1982 as expected. The 1862 observations were then reevaluated and a new orbit was computed. This one had a 130 year period. The comet was then expected to reappear in 1992, which it did.

The reason for wanting to know when a comet returns is that there is generally an enhancement of the numbers of meteors visible. And indeed there was. Every time a comet passes near the sun some of its frozen gases boil off liberating dust and bits of rock. These end up orbiting the sun near the comet’s orbit in an elongated swarm. The swarms don’t necessarily coincide, so sometimes the earth hits them, or really pass through one or another of them. Over the centuries Comet Swift-Tuttle has laid down a general haze of meteoroids that is fairly wide. The Perseids last for over two weeks, though the peak lasts for a very few hours. Within this haze are denser cores from the more recent passages of the comet.

The radiant of the Perseids is circumpolar for mid northern hemisphere locations, so it’s always in the sky. That means that the Perseids can be seen from the time the sky gets dark enough to see the stars to dawn. Though the numbers of meteors are diminished when the radiant is low as it gets dark in the evening, these meteoroid bits are just grazing the atmosphere, so they show long meteor trails. There’s nothing so grand to see as a Perseid streak along the Milky Way high in the sky.

The radiant starts the evening low in the northeast. As the night turns to early morning the radiant will rise higher in the northeast, and the numbers of meteors will rise, though their streaks will be shorter and will appear to move slower the closer they appear to the radiant. This month’s star chart will show the radiant at 11 p.m.
Get warm and comfortable for the great summer meteor show!

The Bad Astronomer and NASA have more information and links.

Tags: Events, Observing by Bob Moler
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Perseid Meteors

August 12-13 is the peak of the Perseid meteor shower. This is a great meteor shower year in and year out. The meteor shower starts in late July and run until the 20th or so of August. Below is an Image of a Perseid meteor I shot years ago. Of all the film I’ve used on the Perseid over the years, this is the only shot good enough to print, so to speak.

Here’s a link to NASA’s web page on this year’s Perseid shower.

Total Lunar Eclipse

The morning of August 28th will see a total eclipse of the moon. We’ll see a bit more than half of the eclipse before the moon sets here in Michigan. Folks farther west will see the whole eclipse. Below in an image created using Stellarium of the partially eclipsed moon. An animation can be found on the Ephemeris web site. The NASA data for this eclipse is found here.

The times below are Eastern Daylight Time. Since the event is happening to the moon, you need only correct for your time zone.

Moon enters umbra, the partial phase begins: 4:51 a.m.
Totality begins: 5:51 a.m.
Full Moon: 6:34 a.m.
Middle of eclipse: 6:37 a.m.
Sunrise at Interlochen/Traverse City: 7:00 a.m.
Moon set at Interlochen/Traverse City: 7:04 a.m.
Totality ends: 7:22 a.m.
Moon leaves umbra, the partial phase ends: 8:24 a.m.

Update:  Here’s another NASA link.

Milky Way

Clear moonless nights will reveal the wonders of the Summer Milky Way, a treat for binoculars and telescopes.

Mars Hoax

One event won’t occur. Yet again there is a hoax email circulating the Mars will be extraordinarily close on August 27th. “Appearing as large as the moon”, so they said. Well it was close… in 2003. Mars will be relatively close again December 19th of this year, however it will only be as close as 54.7 million miles on that date. Back in 2003 it was nearly 34.5 million miles away, appearing nearly twice as large as it will in December. Even in 2003 it appeared very small in telescopes.

Tags: Events, Observing by Bob Moler
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