10/14/2022 – Ephemeris – The loneliest star in the sky isn’t so lonely this year, and more

This is Ephemeris for Friday, October 14th. Today the Sun will be up for 11 hours and 2 minutes, setting at 6:59, and it will rise tomorrow at 7:58. The Moon, 3 days before last quarter, will rise at 9:37 this evening.

There’s a bright star that appears for only seven and a half hours on autumn evenings. It’s appearance, low in the south-southeast at 9 p.m., is a clear indication of the autumn season. The star’s name is Fomalhaut, which means fish’s mouth. That’s fitting because it’s in the constellation of Piscis Austrinus, the southern fish. At our latitude it’s kind of the fish that got away, because Fomalhaut appears to be quite alone low in the sky. The other stars of its constellation are dim, and being low in the sky makes them even dimmer. However, this year Fomalhaut has visitors. Above and left of it is the brilliant planet Jupiter. And above and right of it is the bright planet Saturn. Both planets, while not very close to Fomalhaut, will keep it company this year.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addenda

Fomalhaut and friends (Jupiter and Saturn) finder animation for 9 pm tonight, Friday, October 14, 2022. Click on the image to enlarge it. Created using Stellarium and GIMP.

Also at Corson Auditorium on the Interlochen Center for the Arts Campus…

Join Interlochen Public Radio for Kids Commute Live! This family-friendly matinee is brought to you by the Interlochen Arts Academy Wind Symphony and features Interlochen theatre and singer-songwriter students, TCAPS middle school musicians, and special guests from NASA, the Coast Guard, and the International Dark Sky Park. Conductor Matthew Schlomer and Kids Commute host Kate Botello will lead this multi-sensory experience centered on the theme “Space Flight.”
The program will include Gustav Holst’s “Jupiter,” Michael Mogenson’s “Aerial Fantasy,” John Williams’ “Fantasy of Flight,” and more!
Come early for pre-concert activities for kids of all ages, including drone demonstrations and paper airplane contests. Space-themed food will be available for purchase.
I will be there from 12 to 1 pm, having the kids help me make COMETS! I’ll also be part of the program. 

For more information and tickets: https://www.interlochen.org/events/kids-commute-live-space-flight-2022-10-15

 

07/12/2022 – Ephemeris – The rest of the first images and data from the James Webb Space Telescope to be released tomorrow

This is Bob Moler with Ephemeris for Tuesday, July 12th. Today the Sun will be up for 15 hours and 18 minutes, setting at 9:27, and it will rise tomorrow at 6:09. The Moon, 1 day before full, will set at 5:26 tomorrow morning.

Later today at 10:30 am, NASA and the Space Telescope Science Institute will present the first results from the James Webb Space Telescope. These will be, I believe, four multi-spectral images rendered in full color, and other data. The wavelength coverage of Webb in the infrared is greater than Hubble Space Telescope, which is mostly visible light, by several factors. The test images we’ve seen released so far are monochromatic and rendered in white, yellow, orange and red to depict a wide brightness range. There will be a Webb image release with explanations at the Milliken Auditorium of the Dennos Museum at 10:30, with doors opening at 10 am; and also at the Main Library in Traverse City. I’ll endeavor to be at the library.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Not known by me last Sunday night when I wrote and recorded today’s program was that President Biden was going to preview one of the images Monday evening. If I were the general public, I would have been underwhelmed. It wasn’t enlarged, or particularly colorful. Here it is below. Click on it for an even larger view:

The teaser deep field image from President Biden’s July 11th presentation. Click on the image to fill your screen with it. Credit: NASA, ESA, CSA, JWST, STScI.

In the image above, anything with diffraction spikes is a star in our galaxy. Everything else is a galaxy, like the Milky Way, with billions of stars. This is a tiny piece of sky. As a rule of thumb, the redder the galaxy, the farther away it is. The light emitted by these galaxies are starlight in mostly visible wavelengths, but shifted to the infrared by their great speed of recession caused by the expansion of space between us and them. Also note that many of these galaxies are distorted into short arcs. They seem curved as if being part of a circle around the large, bright galaxy in the center. This is caused by the gravitational lensing caused by the mass of that galaxy, dark matter, and other galaxies in its cluster. This is an effect predicted by Einstein’s theory of General Relativity. I have a feeling that we are going to see a lot more gravitational lensing as the JWST probes into deeper and deeper fields.

One thing to remember about deep fields, is that because of the speed of light being finite, that the farther we look out, the farther back in time we see into an evolving universe. The farthest back we can see with electromagnetic radiation (that is gamma rays, x-rays, ultraviolet, visible, and infrared light, microwaves and radio waves) is the era of the cosmic microwave background, when the universe became transparent, about 380 thousand years after the Big Bang. After that came a period called the dark ages before galaxies formed and the first stars ignited, called the dark ages. At least that’s what I hear-tell. There are lots of questions, like the chicken and egg question: Which came first, supermassive black holes or galaxies?

We will find answers to some of our questions, I’m sure. Even more intriguing, we will be able to ask even more and deeper questions to probe the mystery and beauty of the universe.

07/11/2022 – Ephemeris – First color images from the James Webb Space Telescope will be released tomorrow

This is Ephemeris for Monday, July 11th. Today the Sun will be up for 15 hours and 20 minutes, setting at 9:28, and it will rise tomorrow at 6:08. The Moon, 2 days before full, will set at 4:19 tomorrow morning.

Tomorrow at 10:30 am, NASA and the Space Telescope Science Institute will present the first results from the James Webb Space Telescope. These will be, I believe, four multi-spectral images rendered in full color, and other data. The spectral range of Webb in the infrared is greater than Hubble Space Telescope by several factors. Hubble operates mostly in visible light and plus a bit in the ultraviolet and the near infrared. The current alignment images released are monochromatic and rendered in orange for aesthetic reasons, and to hint that these are from the long wavelength part of the spectrum. I expect the new images to look as great or better than anything the Hubble has produced. There will be a Webb image release and celebration at the Milliken Auditorium of the Dennos Museum at 10:30, with doors opening at 10 am; and also at the Main Library in Traverse City.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

The alignment image of the James Webb Space Telescope after the 18 primary mirror segments have been aligned to act as a single mirror. Beside the alignment star showing its overexposed diffraction spikes, many faint galaxies can be seen. The alignment star, near the Big Dipper, is almost too faint to be seen in binoculars. Credit: NASA, Space Telescope Science Institute (STScI).

Webb Fine Guidance Sensor (FGC) test image guiding on a star for 72 exposures totaling 32 hours over 8 days. The color key to brightness is white, yellow, orange, red for bright to dim. The black cores to the stars, and at least one galaxy is due to saturating the pixels due to brightness, and are not black holes. Credits: Canadian Space Agency, NASA, FGS team. The Fine Guidance Sensor is a contribution to the James Webb Space Telescope by the Canadian Space Agency.

04/15/2022 – Ephemeris – How the date of Easter is determined

This is Ephemeris for Good Friday, April 15th. Today the Sun will be up for 13 hours and 29 minutes, setting at 8:27, and it will rise tomorrow at 6:56. The Moon, 1 day before full, will set at 7:04 tomorrow morning.

Easter will be celebrated by Western Christian churches this Sunday. Easter is a movable feast in that it falls on a different date each year following the first full moon of spring. It’s an attempt to follow the Jewish Passover, which starts on the 15th of the month of Nisan. The Jewish calendar being a lunar calendar, the 15th is generally the night of the full moon. And since the Last Supper was a Seder, according to at least one Gospel, the Christian church wanted to link Easter with Passover as closely as possible using the Roman solar based (Julian) calendar. The months didn’t follow the cycle of the Moon anymore and where the year was 365.25 days long. Passover starts at sunset tonight. The western churches adopted the Gregorian calendar to keep in sync with the seasons. The Orthodox churches didn’t, so their Easter is a week later this year. They kept the old Julian Calendar and other considerations to calculate the date of Easter.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

If you’re wondering about what all this has to do with astronomy? The answer is: Everything! Astronomy in ancient times wasn’t about the nature of planets, and stars, but about the cycles about the Sun and Moon. These cycles announced the seasons, and festival times. This is how the date of Passover is set. The Jews, at least in the Bible, only referenced the constellations of Orion and the Great Bear plus the star cluster Pleiades, that scholars have pinned down. There are two more possible references to constellations that don’t translate. These are all in the Book of Job. The only planet mentioned is Saturn, because it was thought to be closest to the firmament, the starry sphere.

07/28/2020 – Ephemeris – The Mars Endurance Rover may launch to Mars on Thursday

This is Ephemeris for Tuesday, July 28th. Today the Sun will be up for 14 hours and 47 minutes, setting at 9:12, and it will rise tomorrow at 6:26. The Moon, 1 day past first quarter, will set at 1:49 tomorrow morning.

This Thursday at 7:50 am is the first opportunity to launch the Mars 2020 or Perseverance Rover to Mars to arrive on February 18th 2021. The rover will be launched on a United Launch Alliance Atlas 5/Centaur rocket with 4 solid boosters. To send a payload to Mars one must launch within a specific window of time called a launch period. This was originally from July17 to August 11th. Some issues with testing caused a delay to July 30th. The launch period was extended to August 15th. Miss that and it’s a wait of 26 months until Earth and Mars are in the same relative position to try again. The landing area or ellipse is less than 6 miles long on the long axis and partially overlaps an ancient dried river delta that flowed into Jezero crater.

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

Addendum

An artist’s concept of the Mars 2020 Rover launch. The rocket is an Atlas V with 4 solid boosters and a Centaur upper stage. Credit NASA.

 

11/11/2019 – Ephemeris – Mercury is passing across the face of the Sun today

Ephemeris for Veteran’s Day, Monday, November 11th. Today the Sun will be up for 9 hours and 45 minutes, setting at 5:19, and it will rise tomorrow at 7:35. The Moon, 1 day before full, will set at 7:24 tomorrow morning.

Today we are bring treated by a rare event. The planet Mercury is crossing the face of the Sun. It’s called the transit of Mercury. The last one visible from around here was 3 ½ years ago, and the next one will be visible here in 2049. The transit starts at sunrise when Mercury starts to cross the Sun from the lower left from sunrise and will cross the Sun until 1:04 p.m. where it will leave the Sun at the upper right. The best way to see it will be to project the Sun’s image on a white card using binoculars or a telescope. Do not look through them at the Sun. Solar eclipse glasses will not work because Mercury is too small. Do not use eclipse glasses with binoculars. The Sun’s heat will melt the filters and cause blindness.

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

Addendum

One or more members of the Grand Traverse Astronomical Society mayl be out in the parking lot of Mari Vineyards 8175 Center Road on Old Mission Peninsula, but only if it’s clear. Be advised that there is a winter storm warning for the Grand Traverse Area from 1 a.m. to 6 p.m. today.  That means that chances are slim that we’ll have a big enough clear spot to observe through.  But I’ll be on the look out., and am a half an hour away.

I found a source for streaming video fo the transit from Griffith Observatory in Los Angeles:  https://www.youtube.com/watch?v=rYZKNhTJmOI.

Being on the west coast they will miss part of the transit.  They’ll go live at 9:15 a.m. our time.  Sunrise over there is at 9:22 our time.  There’s more information on: http://www.griffithobservatory.org/events/Transit_of_Mercury_2019.html.

More information about viewing the transit is on: https://spaceweather.com/

Path of Mercury across the Sun. The planet will move from lower left to upper right. The passage will be from lower left to upper right. Credit: Occult 4.

I’m demonstrating using binoculars to project the Sun. Photo by Bea Farrell (granddaughter).

Mercury Inferior Conj.  (Transit) 
Transit of Mercury on 2019 Nov 11 (TT)
     Geocentric Event      UTC          EST          P.A.
                           h  m  s                      o 
[1]  Exterior Ingress      12 35 27    7:35.27 a.m.  110.0
[2]  Minimum Separation    15 19 48   10:19:48 a.m.
[3]  Exterior Egress       18  4 14    1:04:14 a.m.  298.6

Minimum sepn 75.9";  Radii - Sun 969.3", Mercury 5.0"
delta T =  70.2 secs,  Ephemeris = DE0

The Sun facing side of the Earth at the start and end of the transit. If you can see your location on either of these maps the transit or part of it will be visible from your location. Credit Occult 4.

09/29/2016 – Ephemeris – The Rosetta spacecraft starts its fatal dive today

Ephemeris for Thursday, September 29th.  The Sun will rise at 7:38.  It’ll be up for 11 hours and 47 minutes, setting at 7:26.  The Moon, 1 day before new, will rise at 7:09 tomorrow morning.

Tomorrow morning at 6:40 a.m. give or take 20 minutes the European Space Agency’s Rosetta spacecraft will slowly crash into Comet 67P/Churyumov-Gerasimenko after orbiting it for a bit over 2 years.  The comet is carrying Rosette out toward Jupiter’s orbit where the spacecraft cannot receive enough sunlight to power it.  Today the controllers will command the spacecraft to perform the collision maneuver to cancel Rosetta’s complete orbital velocity and let it fall straight down to hit the head of the rubber ducky shaped comet.  It’s antenna will be facing Earth and it will be taking pictures all the way down for immediate transmission because Rosetta will turn off its transmitter forever when it impacts the comet.

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

Addendum

An artist’s illustration of the European Space Agency’s comet-chasing Rosetta spacecraft. Credit: ESA – C. Carreau

Rosetta, Final orbit. Credit & copyright European Space Agency (ESA)

06/06/2016 – Ephemeris – Venus passes behind the Sun today

Ephemeris for Monday, June 6th.  Today the Sun will be up for 15 hours and 27 minutes, setting at 9:25, and it will rise tomorrow at 5:57.  The Moon, 2 days past new, will set at 10:52 this evening.

Today the planet Venus will be in superior conjunction with the Sun, and indeed will pass directly behind the Sun.  That event will be completely unobservable due to the Sun’s brilliance.  Fours years ago we observed the transit of Venus across the Sun.  June 6, 2012.  It got me thinking.  Transits of Venus occur in pairs 8 years apart followed by a very long interval of over 100 years.  It turns out the Venus orbits the Sun 13 times in approximately the same time that the earth orbits the Sun 8 times.  In 4 years Venus goes around the Sun 6 ½ times and put’s Venus behind the Sun 4 years after 2012.  Today to be precise.  In another 4 years we’ll have Venus between the Earth and the Sun again, except Venus will be a bit too far north to transit the Sun.

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

Addendum

SOlar and Heliospheric Observatory (SOHO) stationed at the Earth-Sun Lagrangian point 1 (L1) a million miles sunward of the Earth. Sent back this animated GIF of Venus approaching the Sun in the last few days. In the LASCO C2 coronagraph the large disk at the center blocks the brightest part of the Sun’s image. The white circle represents the Sun’s disk size. Credit ESA/NASA.

Aldebaran Occultation November 26, 2015 from Northern Michigan

On the early morning of November 26th, that’s Thanksgiving morning here in the US,  The Moon will pass in front of, or occult, the bright star Aldebaran in Taurus the bull.  The event is called an occultation.

Three first magnitude stars can be occulted by the Moon,  Aldebaran, Regulus in Leo the lion, Antares in Scorpius the Scorpion, and Spica in Virgo the virgin, since these stars lie within 5 1/2 degrees of the ecliptic, the plane of the Earth’s orbit.  The Moon’s orbit is inclined to it by 5º 14′.  Also because the Moon’s orbit precesses over a period 18.6 years they occur over the Earth in monthly series every 18.6 years.  There are 43 monthly occultations that will occur in this series, which actually started in January.  This is the best of them so far.  We’ll have another on the evening of January 19th next year.  Below is a chart of the event from the Astronomical Almanac Online which can be accessed here:  http://asa.usno.navy.mil/.

Map of the area where the occultation of Aldebaran is visible. Credit: Astronomical Almanac Online – U.S. Nautical Almanac Office, United States Naval Observatory (USNO), in the United States and Her Majesty’s Nautical Almanac Office (HMNAO), United Kingdom Hydrographic Office (UKHO), in the United Kingdom.

The occultation will be visible for locations within the nested grid of curved lines.

The two important events of the occultation is the star’s disappearance and reappearance.  The times of these two events depend on your location, and are scientifically useful in determining the precise position of the Moon.

I’ve worked out the timings for my location about half way between Traverse City and Interlochen, so they should be within a couple of minutes of your observed time if you’re within 30 or so miles.  Go out early, the earlier the better.  The Moon will be especially bright, being only 12 hours after the instant the Moon will be full.  Binoculars or a small telescope will be necessary to spot Aldebaran.  The farther away Aldebaran is away from the Moon the easier it can be picked up.  Note as a rule of thumb, the Moon moves its own diameter against the stars in about an hour.

For the Traverse City/Interlochen area I calculate the disappearance of Aldebaran at 5:38 a.m.

Aldebaran just prior to it’s disappearance behind the Moon from Interlochen/Traverse City. Created using Cartes du Ciel (Sky Charts).

For the Traverse City/Interlochen area I calculate the reappearance of Aldebaran at 6:29 a.m.

Aldebaran just after it’s reappearance from behind the Moon from Interlochen/Traverse City. Created using Cartes du Ciel (Sky Charts).

The Moon will be low in the western sky.

Timings for 3 locations in Michigan

This can be used to approximate the occultation time for other locations in Michigan.

City(s)                    Disappears  Reappears Location
Ironwood          5:33 a.m.   6:25 a.m. Northwestern corner of the
                                        Upper Peninsula (UP) of
                                        Michigan
Interlochen/      5:38 a.m.   6:29 a.m. Northwestern lower Michigan
   Traverse City
Monroe            5:45 a.m.   6:29 a.m. Southeastern corner of Michigan

Estimating timings for your location

I used Cartes du Ciel the free software that I have a link to on the right.  Make sure that the program is set for topocentric positions under Setup/Solar System.  And you have entered your position under Setup/Observatory.  You can find your location in Google Earth.

You can also use Stellarium.  Just make sure the Moon is normal sized.

In both programs you can lock the Moon or Aldebaran in the center of the screen Pick a time in advance of the occultation and using the set time window walk the star towards the Moon, mark the time.  Then walk the star out from the Moon and record the reappearance time.  That’s it.

This should work with other planetarium programs too.

03/19/2015 – Ephemeris – A remarkable solar eclipse tomorrow, however we, in the US, won’t see it.

Ephemeris for Thursday, March 19th.  The Sun will rise at 7:48.  It’ll be up for 12 hours and 5 minutes, setting at 7:53.   The Moon, 1 day before new, will rise at 7:50 tomorrow morning.

There will be a rare solar eclipse tomorrow.  The bad news is that it won’t be visible from here. Be that as it may, it is total for a circle of ocean near Greenland, and because tomorrow is also the vernal equinox the it is also sunrise at the north pole.  As it happens the path of the eclipses totality tracks to the north pole, so the eclipse, partial and total will be visible from there.  I’m not sure how long it’s been since an eclipse totality was visible at the pole on an equinox.  The next solar eclipse visible from the United States will be on August 21, 2017.  This is an eclipse, whose path of totality crosses the continental United States.  In about 2 weeks we’ll have a lunar eclipse whose first stages can be seen from northern Michigan in morning twilight.

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

Addendum

Pertinent section of the March 20, 2015 total solar Eclipse map. Click on image above for the entire image. Credit: Fred Espenak, NASA’s GSFC.