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11/12/2017 – Ephemeris Extra – Venus and Jupiter will appear together tomorrow morning

November 12, 2017 1 comment

Just a quick note.  I’ll talk about it in more detail tomorrow on the program, but this post will get you a full day heads up.  Venus and Jupiter have been approaching one another, at least from the Earth’s point of view for some time.  Monday morning their path’s will seem to cross, with Jupiter heading away from the Sun and Venus heading toward the Sun.

Venus and Jupiter in conjunction

Venus and Jupiter in conjunction at 7 a.m. November 13, 2017. Venus will be 6 times brighter than Jupiter. They will appear half the width of the Moon apart. Created using Stellarium.

These planets will rise at 6:22 a.m., a bit more than an hour before sunrise, at 7:36 a.m.

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

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11/05/2017 – Ephemeris Extra – There will be an Occultation of Aldebaran tonight*

November 5, 2017 1 comment

This posting will not be broadcast.

* Or tomorrow morning, depending where you are.

Ephemeris extra for Sunday, November 5th. The Sun will rise at 7:25. It’ll be up for 10 hours and 5 minutes, setting at 5:25. The Moon, 2 days past full, will rise at 7:01 this evening.

Tonight just after 8 p.m. the bright star Aldebaran will disappear at the left edge of the Moon. Aldebaran is angry red eye of Taurus the bull. The star will reappear at the dark upper right edge of the Moon. Start looking at 8 p.m. or before. Use binoculars or a small telescope to spot the star against the glare of the bright Moon. The star is nowhere as bright as shown in the illustrations below. Star appearances and disappearances appear instantaneous, unlike what the illustrations show.

Aldebaran Occultation begins at 8:07 p.m. EST (1:07 UTC Nov 6th)
Aldebaran Occultation ends at 9:00 p.m. EST (02:00 UTC Nov 6th)

Note the times are for the Traverse City/Interlochen area. It will vary by a few minutes for northern lower Michigan.  The position angles of the entrance and exit points of Aldebaran will also be different.

Otherwise use a planetarium program like Stellarium to preview the event. However, set the program for topocentric coordinates. In Stellarium that’s in the Configuration window, Tools Tab and check the Topocentric coordinates box. Topocentric coordinates are the apparent positions for your location on the Earth. So also make sure your location is correct. The geocentric conjunction of the two bodies will be November 6, 2:42.9 UTC, so it will occur after midnight on the morning of November 6th for locations in northern Europe and Asia.

Addendum

Occultation Map

Occultation Map for the occultation of Aldebaran by the Moon . Credit Occult 4 program from IOTA.org.

Occultation start

Aldebaran at the start of the occultation at 8:07 p.m. for the Traverse City/Interlochen area. Created using Stellarium.

Occultation end

Aldebaran at the end of the occultation at 9:00 p.m. for the Traverse City/Interlochen area. Created using Stellarium.

10/05/2014 – Ephemeris – The Harvest Moon

October 5, 2017 Comments off

This is Bob Moler with Ephemeris for Thursday, October 5th. The Sun will rise at 7:45. It’ll be up for 11 hours and 29 minutes, setting at 7:15. The Moon, at full today, will rise at 7:38 this evening.

This is the day of the Harvest Moon. It will rise just before sunset and colored like a huge pumpkin. The huge size is an optical illusion, and the coloring is courtesy of our Earth’s atmosphere selectively bleeding out the blue from the Moon’s light. The reason the Harvest Moon is so special is that during this period the Moon rises for quite a few days just before and in twilight, effectively lengthening the hours of light that farmers can have to harvest their crops. Tomorrow the Moon will rise 32 minutes later than tonight, rather than the average 50 minutes. The effect is a bit diminished this year because the Moon is nearing perigee, its closest to the Earth and is traveling a bit faster than average. The Moon can get down to a 25 minute day-to-day difference.

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

Addendum

Harvest Moon

The position of the Moon for 7 nights centered on moon rise tonight (10/04/2017). The rotation of the Earth carries the Moon to rise parallel to the green celestial equator line. The brown area at the bottom is below the horizon. Click on the image to enlarge. Created using Cartes du Ciel (Sky Charts).

09/07/2017 – Ephemeris Extra – The Earth is currently under a G4 Geomagnetic Storm – Aurora’s may be visible

September 7, 2017 1 comment

Aurora Alert

At this time (0300 UT  September 8, 2017) the Earth is experiencing a strong geomagnetic storm see Spaceweather.com.

Also check out the NOAA Space Weather Prediction Center.  Check the Aurora Forecast.

Ephemeris Extra: My report of the total solar eclipse August 21, 2017

August 24, 2017 1 comment

In planning for this eclipse may main goal was to keep away from crowds and traffic as much as possible.  I originally wanted to stay in Springfield, IL so I could go west or south.  Earlier in the previous week I talked with the University of Missouri Extension service, and offered my services, so I felt kind of was obligated if the weather was half way decent. They were set up at the Howard County Fairgrounds in Fayette, MO.  It turned out that I couldn’t get a room in Springfield, but could 60 miles north in Bloomington.  One of the enticements to placate my granddaughter about the trip, was to visit some Lincoln sites in Springfield, which we did on Sunday the 20th.  On Saturday and Sunday the 19th & 20th the weather forecast for Fayette looked bad with clouds and rain in the afternoon.  So I made plans and checked routes in the direction of Paducah, KY.

Traffic heading south on I-55

Traffic heading south on I-55 by Springfield. Photo by Stephany Farrell.

I decided, after seeing the traffic heading down to south Illinois on I-55, that if the weather forecast improved for Fayette, MO I’d head there instead. By 11 p.m. the forecast for Fayette improved markedly. It was for partly cloudy skies, and the rain forecast for the afternoon was moved to Tuesday.

We headed out from our Bloomington, IL motel at 3 a.m. The sun came out just before we entered Missouri. The sky was mostly clear with cirrus and some stratus clouds, mostly in the south and west. There was no unusual traffic all the way there.

We were the first to arrive at 8 a.m. About a half hour later we were joined by folks in two cars from Ottumwa, IA. We all stuck pretty much together for the day, away from the building where most of the people, and entertainment was. All in all there were no more than a hundred people there.

Clouds

Beautiful, but not so friendly clouds. Photo by Stephany Farrell.

Definitely unfriendly clouds

Definitely unfriendly clouds. Photo by Stephany Farrell.

As first contact approached it got progressively cloudier. After first contact I went over to the big shed where the entertainment was and some vendors, and gave a short talk on what to expect as totality approached.  We had a $5 hamburger lunch provided by the Howard County Cattlemen’s Association. And bought $10 eclipse T-shirts. For the most part the Sun was visible through the clouds, if hazily. After first contact the skies worsened, eventually losing the Sun at one point, but then the Sun’s image improved, and continually so up to 4th contact. At totality the Sun’s inner corona was visible, but nothing beyond that. So my grand photographic plans were for naught.

However my little action camera recorded the sky for a 45 minutes or so around the time of totality. And with playing it back yesterday, found that it recorded the Moon’s shadow going over very well. From it I’ve created 2 videos, one showing totality in real time, the other a time lapse 2 minute video of 20 minutes centered on totality, in which the shadow of the Moon can be seen passing over us, darkening the translucent clouds from west to east.

I gave my granddaughter, Bernadette (Bea) the job of recording the temperatures as the eclipse progressed.  Here is a chart made from her data:

Bea's temperature chart

Bea’s temperature chart. From data taken by Bernadette Farrell.

The high temperature going in was 94.7 degrees, and the lowest was 78.2 degrees just after totality ended.  It was stinking hot going in.  But around totality there was a cool breeze coming from the southwest.  It was refreshing.

I was going to spend more time soaking up the ambiance of the surreal world of totality this time, instead of staring at the Sun and sky. Well, I got it.

My videos of the eclipse are here:  http://ephemeris.bjmoler.org/EclipseVideos_08-21-17.html.

The eclipse crew

The eclipse crew: Left to Right – Bob, Bea and Stef.

 

 

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.

 

 

Ephemeris Extra – Amateur astronomers produce a “Journey to Jupiter” video from 1,000 images

May 14, 2017 Comments off

This is impressive!  This is on YouTube, but read the explanation from Peter Rosén’s Planetary Society post which also has the video.

NASA requests the assistance of amateur astronomers to observe and record Mars, Jupiter and Saturn to help in observing these planets.  Usually satellites are too close to see the planetary big picture.  And besides amateur astronomers outnumber planetary scientists about a gazillion to one.  They’re the ones to discover storms on these worlds and communicate heads up to either view them from satellites or hunker down as in the case of the solar-powered Opportunity rover.

Thanks to the Planetary Society for the heads up.

Frame from A Journey to Jupiter

A frame from A Journey to Jupiter showing a time-lapse of Jupiter’s rotation and how the belts and zones move at different rates. Credit: The 91 amateur astronomers provided the over 1,000 images to make this video.