07/27/2017 – Ephemeris – Two meteor showers, one peaking another ramping up

July 27, 2017 1 comment

Ephemeris for Thursday, July 27th. The Sun rises at 6:23. It’ll be up for 14 hours and 49 minutes, setting at 9:13. The Moon, 3 days before first quarter, will set at 11:50 this evening.

We are in the season for meteor showers. Today the South Delta Aquariid Meteor Shower will reach peak. This is a not very active shower where the meteors will seem to come from low in the southeastern sky after midnight. The radiant will rotate to the south by 5 a.m. The moon won’t bother it for the next few days. The number of meteors seen will be under 20 per hour. This long-lasting shower will still add a few meteors when the famous Perseid meteor shower begin to appear, which is around now. These meteors will seem to come from the northeastern part of the sky, and will reach peak for us in the evening hours of August 12th. On that night the Moon will brighten the sky after 11:30 p.m. So for the next two weeks both shower meteors can be seen.

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

Addendum

Two meteor showers

The sky at 1 a.m. tomorrow morning, July 28, 2017 showing the South Delta Aquariid (DAqR) and Perseid (PerR) meteor radiants. Created using my LookingUp program.

07/26/2017 – Ephemeris – Let’s check out the bright planets for this week

July 26, 2017 1 comment

Ephemeris for Wednesday, July 26th. The Sun rises at 6:22. It’ll be up for 14 hours and 51 minutes, setting at 9:14. The Moon, 3 days past new, will set at 11:20 this evening.

Let’s take our weekly look at the bright planets. Jupiter is sinking in the west-southwest as it gets dark in the evening. The bright blue-white star Spica, which pales in comparison to Jupiter, is seen left of it. In even the smallest telescopes Jupiter’s four largest moons can be seen. They shift positions from night to night. Jupiter will set at 12:06 a.m. Saturn can now be seen in the south as evening as twilight fades. The reddish star Antares is off to the right of Saturn. Saturn’s rings are spectacular in telescopes. Saturn will set at 3:17 a.m. In the morning sky, brilliant Venus will rise at 3:25 a.m. and be visible until about quarter to 6 tomorrow morning. Mars is in conjunction with the Sun today, that is it’s almost directly behind the Sun, For the last week and the next, no commands will be sent to the orbiters and rovers on Mars due to the radio interference of the Sun.

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

Addendum

Evening planets

Jupiter and Saturn with the southern summer constellations and the crescent Moon at 10:30 p.m., July 26, 2017. Created using Stellarium. Click on image to enlarge.

Binocular Moon

The Moon as it might be seen in binoculars showing also Earth shine at 10:30 p.m. July 26, 2017. Created using Stellarium.

Jupiter and its moons

Jupiter and its moons at 10:30 p.m. July 26, 2017. The Great Red Spot will cross the planet’s central meridian at 11:39 p.m. Created using Cartes du Ciel (Sky Charts).

Saturn and its moons

Saturn and its brightest moons overnight July 26/27, 2017. Created using Cartes du Ciel (Sky Charts).

Venus in the morning

Venus with the stars of autumn at 5 a.m. July 27, 2017. Created using Stellarium.

Telescopic Venus

Venus as it might be seen through a telescope at 5 a.m. July 27, 2017. This is displayed at a larger scale/magnification than the Jupiter or Saturn images above. Created using Stellarium.

Planets and Moon on a single night

Planets at sunset and sunrise of a single night starting with sunset on the right on July 26, 2017. The night ends on the left with sunrise on July 27. Click on the image to enlarge. Created using my LookingUp program.

07/25/2017 – Ephemeris – Why do solar eclipses happen?

July 25, 2017 1 comment

Ephemeris for Tuesday, July 25th. The Sun rises at 6:21. It’ll be up for 14 hours and 54 minutes, setting at 9:15. The Moon, 2 days past new, will set at 10:48 this evening.

We have a day less than 4 weeks before the Great American Total Solar Eclipse on August 21st will occur. Solar eclipses occur at new moon, when the moon is aligned so its shadow falls on the Earth. It doesn’t happen every new moon because the Moon is a long ways away, and its orbit is tipped some 5 degrees from the Earth’s orbit of the Sun, so usually the Moon is north or south of the Sun at new moon. About one in every 6 new moons produces an eclipse. They occur when the Moon is near the crossing point of the two orbital planes, called nodes. The point where the Moon is passing the node in northward direction is called the ascending node, and 180 degrees around the orbit there is the descending node, but you have to be in the right spot to see an eclipse.

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

Addendum

Anatomy of an eclipse

What happens to create a total solar eclipse. Note the Sun’ distance as being 400 times the distance of the Moon. The Sun is also 400 times the Moon’s diameter, so they appear nearly the same size from the Earth. Credit NASA and the Eclipse2017.NASA.gov website.

07/24/2017 – Ephemeris – The celestial scorpion

July 24, 2017 1 comment

Ephemeris for Monday, July 24th. The Sun rises at 6:20. It’ll be up for 14 hours and 56 minutes, setting at 9:16. The Moon, 1 day past new, will set at 10:12 this evening.

Crawling just above the southern horizon at 11 p.m. is the zodiacal constellation of Scorpius the scorpion. His heart is the red giant star Antares. Its facing the west or right with a short arc of three stars as its head. His body and tail drop to the left and scrape the horizon before curving up to the critter’s poisonous stinger of two stars. It really makes a great scorpion. One story of the scorpion concerns Orion the hunter the great winter constellation. In that story Orion was killed by the sting of a scorpion. Therefore Orion and Scorpius are never seen in the sky at the same time. That is certainly true around here and for the Greeks, whose legend it is. However if one travels far enough south that is no longer true.

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

Addendum

Scorpius

Scorpius finder chart for 10:30 p.m., July 24, 2017. Created using Stellarium, which has a bug in the newest version and is also showing Ophiuchus.

07/21/2017 – Ephemeris – There’s an astronomy event tomorrow night

July 21, 2017 1 comment

Ephemeris for Friday, July 21st. Today the Sun will be up for 15 hours and 2 minutes, setting at 9:19, and it will rise tomorrow at 6:18. The Moon, 2 days before new, will rise at 5:28 tomorrow morning.

Tomorrow, Saturday, the 22nd, there, will be viewing of the summer starry skies at the Northwestern Michigan College’s Rogers Observatory starting at 9 p.m. While starting before sunset, if it’s clear Jupiter should be spotted before 10 p.m. The planet Saturn and its rings will also be featured. By 10:30 the sky should be dark enough to spot some of the wonders among the stars, like star clusters, and nebulae that are the either the birth places of stars or the expelled remnants of dying stars. The Milky Way takes over the dark sky, it is its wonders that we see. The Observatory is located south of Traverse City on Birmley road. Take Garfield Road two traffic lights south of South Airport Road to turn right at Birmley Road.

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

07/20/2017 – Ephemeris – Only one month and a day to the Great American Eclipse, and a personal note

July 20, 2017 1 comment

Ephemeris for Thursday, July 20th. Today the Sun will be up for 15 hours and 4 minutes, setting at 9:20, and it will rise tomorrow at 6:17. The Moon, 3 days before new, will rise at 4:26 tomorrow morning.

As of tomorrow it will be one month to the Great American Eclipse, a total eclipse that will span the continental United States from Oregon to South Carolina. Here in northern Michigan, the Sun will be, at maximum 75 percent covered by the Moon around 2:20 p.m. The eclipse will last from 12:58 to 3:40 p.m. approximately. It will not be safe to look at the Sun without a solar filter or by projecting the image of the Sun on a white paper, either with a pinhole, one side of a binocular, or telescope. Hold the paper screen a foot or so behind the eyepiece. Try it before the eclipse. Or sit under a tree, and let the pinholes between the leaves project a myriad of suns on the ground. Check gtastro.org for lots of links to information about the eclipse.

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

Addendum

Eclipse map

All 50 states will see some part of the August 21, 2017 solar eclipse. The face of the Sun will be totally covered by the Moon in the narrow band called the path of totality for up to 2 minutes, 40 seconds. Credit: NASA.

 

Eclipse glasses

These are eclipse glasses which can be gotten for a couple dollars or less.
They are especially difficult to use, especially for people who wear glasses and can’t remove them because they are near-sighted.
Personally I do not recommend them, instead relying on one of the projection methods.
Be especially careful about children using them.
Remember the ISO 12312-2 compliance that should be printed on them. Do not use welders filters.  Damaging exposure to the eyes is painless and may not show up for a day or two.

Filters for telescopes

In using a solar filter with a telescope or binoculars the filter must be placed in front of the objective (front of the telescope).
Solar filters that fit into eyepieces are dangerous and can shatter with the heat.
Such filters should either be smashed and added to your favorite landfill, or taken to the bay to see how many times you can skip it on the water.

Pinhole projection

Pinhole projection is the simplest way to project the Sun’s image.
A long box can be used to project the image inside. The diameter of the pin hole is a compromise between sharpness and brightness of the image.
…The farther the image is projected the larger it is.
The throw of the image can be increased by using a mirror masked with a quarter of an inch or larger hole and sending the image 10 or more feet away.

Tree provided pinholes

Let nature provide the pinholes. Sit under in the shade. Stay cool, And watch the Sun’s images on the ground.

Telescope eyepiece projection

Here’s an 8” Schmidt Cassigrain telescope, with a low power eyepiece projecting a large image on a movie screen. For lots of people to view and photograph.  Credit Eileen Carlisle.

Solar Eclipse Guide Scope

This is my Solar Guide Scope which I used for all my solar eclipses starting with 1970 (three total and 2 annular).
It is an open design, with an objective of about 300mm (12”) focal length, a shield to shield the screen from the Sun, a cheap 12mm (1/2”) focal length eyepiece and an adjustable screen to project the Sun’s image.  I originally made it too short, so I extended it.  It always attracts a crowd of eclipse watchers.

July 20th in history

48 years ago (1969) Apollo 11 landed on the Moon

41 years ago (1976) the Viking 1 Lander landed on Mars.

On a personal side:  54 years ago (1963) I saw my first total solar eclipse.

The 54th anniversary isn’t the big deal.  The big deal has to do with the Saros, the period in which eclipses repeat.  That interval is 6,585.3211 days or approximately 18 years 11 1/3 days, give or take a day, depending on the number of leap years in the interval.  That one-third day is the kicker, because the next eclipse in the series will occur 120 degrees of longitude west of the last eclipse.  There are many Saros series running at any given time, so eclipses don’t only happen every 18 years.

However after 3 Saros periods the eclipse will again occur at roughly the same longitude.  If the Moon  passes the Sun moving slightly southward, the eclipse series will trend southward on the globe.  If northward, the series heads north.

The eclipse of August 21st 2017 is the third Saros eclipse after my first total solar eclipse

Since this upcoming eclipse tracks southward, the 1963 eclipse was farther north with the path of totality passing through Alaska, Canada and only the state of Maine.

On that day, friends John Wesley, Dave DeBruyn and several other members of the University of Michigan team, and Stan Carr, a member of the Muskegon Astronomy Club found ourselves on a hill overlooking the St. Maurice River in Quebec Province of Canada.

Overlook

Overlooking the St Maurice River from our camp in the morning with the clouds then. But the eclipse would start about 4:30 in the afternoon.

2 p.m.

At two p.m. and we’re socked in. Seen is John Wesley and our automated eclipse camera. 2 1/2 hours to totality.

Happy Day!

Happy day! The eclipse is starting, and it’s clearing up.

Tracking

John Wesley checking the tracking of our eclipse camera.

It was for naught.  Due to an operator error all the film was wound up when power was applied to the controller, because I left a switch in the wrong position.

Totality

A shot with a 50mm lens with a guessed exposure. Thanks to GIMP and modern digital processing I was able to recover the over exposed image. But like all eclipse photographs, doesn’t really show it as the eye reveals the dynamic light levels of the corona.

 

 

 

 

07/19/2017 – Ephemeris – Our weekly look at the bright planets

July 19, 2017 1 comment

Ephemeris for Wednesday, July 19th. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:21, and it will rise tomorrow at 6:16. The Moon, 3 days past last quarter, will rise at 3:33 tomorrow morning.

Let’s take our weekly look at the bright planets. Jupiter is in the west-southwest as it gets dark in the evening. The bright blue-white star Spica, which pales in comparison to Jupiter, is seen left of it. In even the smallest telescopes Jupiter’s four largest moons can be seen. They shift positions from night to night. Jupiter will set at 12:32 a.m. Saturn can now be seen in the evening as twilight fades in the south. The reddish star Antares is off to the right of Saturn. Saturn’s rings are spectacular in telescopes. Saturn will set at 3:46 a.m. In the morning sky, brilliant Venus will rise at 3:22 a.m. and be visible until about quarter to 6 tomorrow morning. Mercury sets too close to sunset to be easily seen now.

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

Addendum

Jupiter and Saturn

Jupiter and Saturn with the southern summer constellations at 10:30 p.m., July 19, 2017. Created using Stellarium. Click on the image to enlarge.

Jupiter and moons

Jupiter and three of its moons. Io can be seen here in transit of the planet, but very difficult in reality, at 10:30 p.m,. July 19, 2017. Created using Cartes du Ciel (Sky Charts).

Project Pluto has the following events for the 12/13th:

Time is UT.  Events prior to 20 July 2:35 UT (10:35 p.m. 19 July EDT) or later than 4:24 UT or 12:24 a.m. EDT will not be visible from Northern Michigan.  Data from Project Pluto:  https://www.projectpluto.com/jevent.htm#jun.  The website also has a link to a list of Great Red Spot transits.

I : Tra start: 20 Jul 2017 1:21
I : Sha start: 20 Jul 2017 2:35
I : Tra end : 20 Jul 2017 3:32
II : Occ start: 20 Jul 2017 4:24
I : Sha end : 20 Jul 2017 4:46
II : Occ end : 20 Jul 2017 6:54
II : Ecl start: 20 Jul 2017 6:55
II : Ecl end : 20 Jul 2017 9:17

Satellites: I = Io and II = Europa

Tra = Transit of a satellite across the face of Jupiter, Sha = Transit of a moon’s shadow, Ecl = Eclipse (In Jupiter’s shadow), Occ = Occultation (Moon behind the planet).

The Great Red Spot transit: 20 Jul 2017 02:50 (10:50 p.m. 19 July EDT).

Saturn and moons

Saturn and its brightest moons overnight July 19/20, 2017. Created using Cartes du Ciel (Sky Charts).

Venus and the Moon

Venus and the Moon at twice its actual size at 5 a.m. July 20, 2017. Created using Stellarium.

Binocular Moon

The Moon as it might be seen in binoculars showing also Earth shine at 5 a.m. July 20, 2017. Created using Stellarium.

Telescopic Venus

Venus as it might be seen through a telescope at 5 a.m. July 20, 2017. This is displayed at a larger scale/magnification than the Jupiter or Saturn images above. Created using Stellarium.

Planets and Moon on a single night

Planets at sunset and sunrise of a single night starting with sunset on the right on July 19, 2017. The night ends on the left with sunrise on July 20. Click on the image to enlarge. Created using my LookingUp program.