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08/14/2018 – Ephemeris – the constellation of Aquila the eagle

August 14, 2018 Leave a comment

Ephemeris for Tuesday, August 14th. The Sun rises at 6:44. It’ll be up for 14 hours and 6 minutes, setting at 8:50. The Moon, 3 days past new, will set at 11:00 this evening.

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 dominating the eastern sky in the evening now. 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 its 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 above and left of Aquila, flying in the opposite direction. ……

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Aquila finder animation

Animated Aquila finder chart. Created using Stellarium.

Actual Aquila

Annotated and animated photograph taken of Aquila August 13, 2018 during the Perseid meteor shower. Alas, no Perseids in this photograph. Taken by me and processed using Registax and GIMP.

Further notes on the Perseid meteor shower

I spent a good chunk of the Perseid peak night (August 12/13) at the Sleeping Bear Dunes National Lakeshore at the Dune Climb observing the Perseids.  Though clear there was a great amount of haze in the air, part of which was smoke from the fires out west, and the barometric high we’ve been under for the past few days getting stagnant,  The blue sky the day before was decidedly milky.  Though the Milky Way overhead was visible, the teapot of Sagittarius below Saturn wasn’t.

A casual inspection of my photographs show only 2 Perseid meteors.

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08/13/2018 – Ephemeris – The Milky Way

August 13, 2018 Leave a comment

Ephemeris for Monday, August 13th. The Sun rises at 6:42. It’ll be up for 14 hours and 8 minutes, setting at 8:51. The Moon, 2 days past new, will set at 10:30 this evening.

Now is the time the summer Milky Way is displayed to its fullest to the southern horizon. We have a couple of nights before the Moon begins to interfere before 11 p.m. City folk come to our area and are sometimes fooled by the brightness and expanse of the Milky Way and think it’s clouding up. Yes those are clouds indeed, but they are star clouds of our galaxy. Binoculars will begin to show them to be millions of stars, each too faint to be seen individually to the eye, but whose combined glow give the impression of a luminous cloud. Binoculars are the ideal tool to explore the Milky Way. Objects still too fuzzy can be checked out with a telescope to reveal their true nature. The dark nights of August and September are my favorites.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Milky Way

The Milky Way from the Sleeping Bear Dunes in August, 2015 by Mark Stewart.

08/10/2018 – Ephemeris – A busy weekend here and in the skies

August 10, 2018 Leave a comment

Ephemeris for Friday, August 10th. The Sun rises at 6:39. It’ll be up for 14 hours and 16 minutes, setting at 8:56. The Moon, 1 day before new, will rise at 6:45 tomorrow morning.

It’s a busy weekend for the Grand Traverse Astronomical Society. Members will be on Front Street in Traverse City tonight for Friday Night Live with views of the Sun and later a look at the planet Saturn and its rings, weather permitting. On Saturday, again weather permitting members will be part of Sleeping Bear Dunes Port Oneida Fair with a Sun ‘n Star Party from 4 to 6 p.m. and from 9 to 11 p.m., though members will still be there in between. The location for that event is the Thoreson Farm on South Thoreson Road off M22, near Port Oneida Road. On tap will be Venus, Jupiter, Saturn, Mars and some of the Perseid meteors on the night before its peak night, plus some of the deep sky wonders of the summer Milky Way.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

White light viewing of the Sun

Viewing the Sun with a while light filter at Friday Night Live using Ron Uthe’s telescope at Friday Night Live. Credit Bob Moler

Friday Night Live

After Friday Night Live was over Saturn was visible until about 11 p.m. Credit: Bob Moler.

Star party 2

Star Party at the Sleeping Bear Dunes National Lakeshore, Thoreson Farm August 2013. Credit Eileen Carlisle.

08/09/2018 – Ephemeris – How to observe the Perseid Meteor Shower

August 9, 2018 Comments off

Ephemeris for Thursday, August 9th. The Sun rises at 6:38. It’ll be up for 14 hours and 19 minutes, setting at 8:57. The Moon, 2 days before new, will rise at 5:30 tomorrow morning.

Now through most of this month and reaching peak numbers Sunday evening and Monday morning the Perseid meteors will be shooting through our skies. Where to look? Up is the direction. All over the sky. They will seem to come from the northeast on parallel paths, like driving through a snow storm at night, the snowflakes will diverge from right in front of you. The numbers will generally increase as that radiant point rises higher in the sky. A diligent experienced, and undistracted, observer may see up to 100 or more an hour. Casual observers will see much less. The longest meteor streaks will be seen early in the evening when the meteoroids enter the atmosphere at 37 miles (59 km) per second at a very shallow angle, so last a bit longer.  Bring a blanket, dress warmly and enjoy the show!

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Perseid Sky Dome Animation

The sky dome for the night of the Perseid shower maximum at 1 hour intervals from 10:30 p.m. to 4:30 a.m. Click on image to enlarge. Created using my LookingUp program and GIMP.

For locations other than the Traverse City/Interlochen area the 10:30 step is approximately an hour and a half after sunset.

My best Perseid photo. From the 70's.

My best Perseid photo. From the 70’s.

Perseid Meteors

Here are some meteors seen in the 2007 Perseid meteor shower taken by Scott Anttila. The image is centered on Cassiopeia. The radiant is low and a bit left of center in the image. The Double Cluster is seen below center and the Great Andromeda Galaxy is seen on the right just above center.

The logic of taking meteor photos pointing near the radiant is the he meteors appear to travel slower there because they are coming mostly toward the camera and have a better chance of being picked up.  My photograph was unguided, so the stars trailed.  Scott’s was guided.

 

08/08/18 – Ephemeris – Let’s check out the bright planets for the week

August 8, 2018 Comments off

Ephemeris for Wednesday, August 8th. The Sun rises at 6:37. It’ll be up for 14 hours and 22 minutes, setting at 8:59. The Moon, 3 days before new, will rise at 4:20 tomorrow morning.

It’s Wednesday and time to look for and at the bright planets. Four of them are visible in the evening sky. The brilliant Venus will be visible in the western twilight from about 9:20 p.m. until it sets at 10:36 p.m. Jupiter will be in the southwest as it gets dark. It is only outshone by Venus, the Moon, and currently Mars. Jupiter will set at 12:26 a.m. Saturn will start the evening low in the southern sky and will stay relatively low, above the Teapot of Sagittarius. It will be due south at 10:46 p.m. and will set at 3:12 a.m.. Mars will be low in the southeast as the skies darken tonight. and is now 36.2 million miles (58.3 million km) away. It is being slowly left behind by the faster moving Earth.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Evening planets

The evening planets visible at 10 p.m., one hour after sunset. August 8th, 2018. Also shown are the constellations. Click on the image to enlarge. Created using Stellarium.

Telescopic planets

Venus, Jupiter, Saturn and Mars with the same magnification at 10 p.m. August 8, 2018. Jupiter’s satellite Io is shown. However at 10 p.m. Io is still is Jupiter’s shadow and will emerge at 11:07 p.m. Mars is also shown enlarged. It seems that the global dust storm is abating, so the albedo features are beginning to be seen. Created using Cartes du Ciel (Sky Charts) which does not properly show Jovian shadow events with the moons.

Binocular Moon

What the Moon might look like at 5:30 a.m., August 9th, 2018 with earthshine. Created using Stellarium.

Planets and the Moon on a single night sunset 08/08/18 to sunrise 08/09/18

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on August 2, 2018. The night ends on the left with sunrise on the 9th. Click on the image to enlarge. Created using my LookingUp program.

08/07/2018 – Ephemeris – The source of the Perseids

August 7, 2018 Comments off

Ephemeris for Tuesday, August 7th. The Sun rises at 6:35. It’ll be up for 14 hours and 24 minutes, setting at 9:00. The Moon, 3 days past last quarter, will rise at 3:18 tomorrow morning.

The Perseid meteor shower will reach its peak Sunday night and Monday morning, less than a week from now. The meteor shower is caused by tiny particles shed by the comet 109P/Swift-Tuttle on past trips through the inner solar system. The 109P means it was recognized as the 109th comet to have seen to return to the vicinity of the Sun to be rediscovered in 1992. Lewis Swift and Horace Tuttle first discovered the comet independently in 1862. The orbit of the comet fit the orbits of the meteoroids that produce the Perseid meteor shower each year. The comet will return in 2126 after retreating to 51 times the Earth’s distance from the Sun, deep in the Kuiper belt, leaving behind a trail of meteoroids.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Swift-Tuttle 1992 plot

The passage of 109P/Comet Swift-Tuttle through the inner solar system November 1, 1992 to January 30, 1993. The meteoroids shed by the comet on its numerous trips close to the Sun lie close to that orbit. Note that its orbit intersects with the Earth’s orbit. That’s where the Earth will be around August 12-13 every year. Click on the image to enlarge. Created using my LookingUp program.

08/06/2018 – Ephemeris – The meteors of August, the Perseids are showing up now

August 6, 2018 Comments off

Ephemeris for Monday, August 6th. The Sun rises at 6:34. It’ll be up for 14 hours and 27 minutes, setting at 9:01. The Moon, 2 days past last quarter, will rise at 2:27 tomorrow morning.

Over the past several weeks folks outdoors at night might have been seeing some shooting stars or meteors appearing to zip past in the sky. The ones I’m talking about seem to come from the northeast. These are the precursors of the Perseid meteor shower which will reach its peak on the night of August 12 and 13 this year. Over the millennia the meteoroid stream that feeds the meteors to our skies has spread out to last over a month from the latter half of July to three-quarters of August. We’ll meet the culprit for this show tomorrow. I try to use the proper terminology for all this. Meteoroid is the tiny body in space. In the Perseid’s case the size of a grain of sand to a pea. Meteor is the streak we see in the sky as it burns up.  Meteorite is the body that makes it to the ground.  To my knowledge no Perseid meteoroid has made it that far.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Perseid radiant

The Perseid radiant at 11 p.m. tonight, August 6, 2018. Note that the radiant position is different from what I show on my charts for the month. The radiant there is for the night of the Maximum, August 12th. The radiant point shifts with time due to Earth’s changing position with the meteoroid stream. Click on image to enlarge. Created using Stellarium.