Archive

Archive for the ‘Observing’ Category

10/13/2017 – Ephemeris – The bright star Regulus dips behind the Moon Sunday morning

October 13, 2017 1 comment

Note:  The original program recorded for this day was erroneous in the timing and appearance of this event.  Occurring about an hour later than reported here.  The Interlochen personnel may or may not replace the original program with the one below.  Also those who downloaded the audio from ephemeris.bjmoler.org before late Thursday night may have downloaded the incorrect mp3.

Ephemeris for Friday, October 13th. The Sun will rise at 7:55 a.m.. It’ll be up for 11 hours and 5 minutes, setting at 7:00 p.m. The Moon, 1 day past last quarter, will rise at 2:08 tomorrow morning.

On Sunday morning the Moon will pass in front of, or occult the bright star Regulus, the brightest star in Leo the lion. This will happen as morning twilight starts. Regulus will disappear at the left edge of the crescent Moon at around 5:47 a.m. A telescope or binoculars may be needed to spot Regulus. Go out at least 5 or 10 minutes early to make sure you can spot the star. Regulus will reemerge at 6:25 at the 11 o’clock position on the dark part of the Moon. Earth shine on the night side of the Moon may be bright enough to see its dark edge. Observers west of us in the United States except the northern most states west of Minnesota will also get a view. Those in specific locations in the northern tier of states will get to see Regulus just graze the north edge of the Moon.

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

Addendum

Occultation start

Occultation of Regulus by the Moon disappearance at around 5:47 a.m. for northern Michigan. Created using Stellarium.

Occultation end

Occultation of Regulus by the Moon reappearance at around 6:25 a.m. for northern Michigan. Created using Stellarium.

Occultation Map

Map showing the locations where the occultation of Regulus will be visible. For the area bounded by heavy lines the occultation will occur at night. Click on image to enlarge. Credit: Occult4 by IOTA.

Advertisements

09/19/2017 – Ephemeris – The Great Rift

September 19, 2017 1 comment

Ephemeris for Tuesday, September 19th. The Sun will rise at 7:26. It’ll be up for 12 hours and 18 minutes, setting at 7:45. The Moon, 1 day before new, will rise at 7:43 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 very high in the east. The western part of the Milky Way ends southwest of the Aquila the eagle. This dark dividing feature is called the Great Rift. Despite the lack of stars seen there, it doesn’t mean that there are fewer stars there than in the brighter patches of the Milky Way. The rift is a great dark cloud that obscures the light of the stars behind it. Sometimes binoculars can be used to find the edges of the clouds of the rift, as stars numbers drop off suddenly. This is especially easy to spot in Aquila the eagle.

The times given 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.

The Great Rift in the Milky Way. Created using Stellarium.

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.

07/20/2017 – 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.

 

 

 

 

07/15/17 – Ephemeris Extra – Possible Auroras to be visible this weekend

July 15, 2017 1 comment

The National Oceanic and Atmospheric Administration (NOAA) Space Weather Prediction Center has issued a Geomagnetic Storm Watch for 16-17 July 2017 UT (Universal Time).  The watch period starts tonight for the US.  The 16th UT starts at 8 p.m. tonight, the 15th EDT.  What it means, among other things, is that the Aurora Borealis (Northern Lights) may be visible from the northern tier of states in the United States and Canada, Scotland, Scandinavia, and Russia.  And maybe even farther south.  See the map below:

Geomagnetic storm map

From the NOAA website. Click on the image to enlarge. Click here for the link mentioned in the image: http://www.swpc.noaa.gov/products/aurora-30-minute-forecast.

This alert was issued due to a Coronal Mass Ejection (CME) from the large, but decaying, sunspot group AR2665 at 2:09 UT on the 14th (10:09 p.m. on the 13th EDT).  The CME is expected to encounter the Earth’s magnetosphere on the 16th.

A tip of the old observer’s hat to spaceweather.com for the heads up email.

07/12/2017 – Ephemeris – Let’s check out the whereabouts of the bright planets

July 12, 2017 1 comment

Ephemeris for Wednesday, July 12th. Today the Sun will be up for 15 hours and 17 minutes, setting at 9:26, and it will rise tomorrow at 6:10. The Moon, 3 days past full, will rise at 11:32 this evening.

Let’s take our weekly look at the bright planets. Jupiter is in the 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 12:58 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 4:15 a.m. In the morning sky, brilliant Venus will rise at 3:23 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

Evnng planets

Jupiter and Saturn with the southern summer constellations at 10:30 p.m., July 12, 2017. Created using Stellarium.

Jupiter and its moons

Jupiter and three of its moons. Europa is behind the planet at 10:30 p.m,. July 12, 2017. Created using Cartes du Ciel (Sky Charts).

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

Time is UT.  Events prior to 13 July 1:47 UT (9:47 p.m. 12 July 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: 12 Jul 2017 23:25
I : Sha start: 13 Jul 2017 0:41
I : Tra end : 13 Jul 2017 1:36
II : Occ start: 13 Jul 2017 1:47
I : Sha end : 13 Jul 2017 2:51
II : Occ end : 13 Jul 2017 4:16
II : Ecl start: 13 Jul 2017 4:20
II : Ecl end : 13 Jul 2017 6:42
III: Occ start: 13 Jul 2017 7:10
III: Occ end : 13 Jul 2017 9:45
III: Ecl start: 13 Jul 2017 12:29
III: Ecl end : 13 Jul 2017 14:40

Satellites: I = Io, II = Europa, and III = Ganymede
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: 13 Jul 2017 02:01 (10:01 p.m. 12 July EDT).

Saturn and its moons

Saturn and its brightest moons overnight July 12/13, 2017. Created using Cartes du Ciel (Sky Charts).

Venus and the Moon

Venus and the Moon at 5 a.m. July 13, 2017. Created using Stellarium. Click on the image to expand.

Telesopic Venus

Venus as it might be seen through a telescope at 5 a.m. July 13, 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 12, 2017. The night ends on the left with sunrise on July 13. Click on the image to enlarge. Created using my LookingUp program.

 

Ephemeris Extra – Some easy summertime deep sky objects

July 8, 2017 1 comment

The finder charts were created using Cartes du Ciel (Sky Charts).  This post is based on my article in the July 2017 Stellar Sentinel, the newsletter of the Grand Traverse Astronomical Society.  It’s part of the Extras section for those receiving the emailed version.

What are Deep Sky Objects?  These are objects, other than individual stars, beyond the solar system generally visible in binoculars or telescopes rather than the naked eye such as galaxies, nebulae and star clusters.

HerculesThe Great Hercules Globular Star Cluster, M13 is the finest globular star cluster in the northern hemisphere of the sky. It is visible from late spring to early autumn. Globular star clusters have populations of hundreds of thousands of stars. They date back to the origin of the Milky Way of ten or a bit more billion of years old. There are only about 150 of these that belong to the Milky Way Galaxy. M13 is visible in binoculars on the western side of the Keystone pattern of stars, about one-third the distance from the north star on that side to the south side. It takes a much larger telescope to see individual stars. The star cluster will be a large circular glow. M92 is another star cluster which is dimmer and will be quite a challenge to find.

The Ring Nebula, M57 is small and cannot be seen with the naked eye or with binoculars, but it is still reasonably easy to find. A nebula is a cloud of gas and/or dust. M57 is in the constellation of Lyra the harp, a constellation visible in summer and early autumn. Point the telescope’s finder about half way between the two southern stars of the parallelogram of stars that’s the harp’s body, Sulafat and Sheliak. Move the telescope in a small spiral enlarging the search pattern by half the field of view at a time. The Ring Nebula will appear a ghostly small circular glow. Once centered, more magnification may be used. The center will be darker than the edge. Inside is a very faint invisible star that blew out its outer layers of gas into a smoke ring near the end of its life.

The Southern Milky Way contains lots of star clusters and nebulae. The chart below can be used to find the many Messier objects. Or just sweep through this gold mine of objects with binoculars or a low power telescope, most of which are in the next spiral arm in toward the center of the Milky Way. As far as the symbols go, open dotted circles are open or galactic star clusters. Crossed circles are globular star clusters. Squares are nebulae. M8, the Lagoon nebula, and M16 the Eagle nebula also contain star clusters. M8 and its associated star cluster appear as a horizontal spash of light in binoculars. As far as popular names go: M11 is the Wild Duck Cluster, M17 is the Omega or Swan Nebula, and M20 is the Trifid Nebula.  An easy binocular star cluster is M7.Southern summer Milky Way DSOs

The Milky Way Overhead contains some notable deep sky objects. Note that the Milky Band splits here, though closer to the star Sadr in Cygnus than it shows here. The Dark expanse that runs through Aquila is called the Great Rift, and is caused by a cloud of dust and gas. Its edges can be probed with binoculars, especially in Aquila by watching star density drop off as one pans through the area. Don’t forget the blue and gold binary star Alberio. There’s another fainter blue and gold binary about a degree directly north of the Ring Nebula, M57. It’s 8th magnitude. The unmarked planetary nebula just above the second ‘l’ in Vulpecula is M27, the Dumbbell nebula. The other Messier (M) numbers are relatively easy to find. The large nebula below Deneb is the North American Nebula which can actually be seen with the naked eye or with binoculars on a moonless night away from city lights. The three-part nebula below Cygni is the Veil Nebula, a supernova remnant and very hard to spot but doable. The cluster Cr 399 (Collinder 399 or Brocchi’s Cluster) is better known as the Coathanger and is best seen in binoculars or a telescope finder, which inverts it, making it a properly oriented hanger.