12/09/2016 – Ephemeris – The earliest sunset

December 9, 2016 Leave a comment

Ephemeris for Friday, December 9th.  The Sun will rise at 8:08.  It’ll be up for 8 hours and 53 minutes, setting at 5:02.  The Moon, 2 days past first quarter, will set at 3:39 tomorrow morning.

In twelve days we will have the shortest day in terms of daylight hours.  But the change isn’t uniformly distributed in the morning and evening.  Tonight and tomorrow evening we will have the earliest sunsets  Sunset times have been within the same minute for the last few days and will continue for the next few.  The latest sunrise will occur on January second.  The reason is that the Sun is traveling faster eastward than average, so the Earth’s rotation takes a little longer each day to catch up with it. Near the solstice the Sun is at a higher latitude, where the longitude lines are closer together, also the Earth is nearing its closest to the Sun, so moves faster its orbit adding to the effect.  The effect exists in June but isn’t as noticeable.

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

Addendum

Analemma

This figure 8 is called an analemma. One can find it on old globes in the Pacific Ocean. Explanation below. Created using my LookingUp program by plotting the Sun at 7 day intervals at local noon for a year.

At the bottom of the analemma is where the Sun is near the winter solstice when it is moving its fastest eastward.  At the top, near the summer solstice the Sun is moving faster than average, but not as fast as it is now.  The Earth will be nearest the Sun on January 4th, a point called perihelion.  Aphelion next year, when the Earth is farthest from the Sun, will be July 3rd next year.

Categories: Ephemeris Program, Seasons Tags:

Godspeed John Glenn

December 8, 2016 Leave a comment

With these words from the Capcom John Glenn was launched into the clear Florida sky on February 20, 1962, the first American to orbit the Earth. I cut my college classes to witness the launch on TV that day. He and Alan Shepard were the astronauts of firsts in the Mercury program and my special heroes. With Glenn’s passing all the Mercury astronauts now belong to history.

Godspeed John Glenn and Rest in peace.

12/08/2016 – Ephemeris – Aldebaran, the follower

December 8, 2016 Leave a comment

Ephemeris for Thursday, December 8th.  The Sun will rise at 8:07.  It’ll be up for 8 hours and 54 minutes, setting at 5:02.  The Moon, 1 day past first quarter, will set at 2:26 tomorrow morning.

The central constellation of winter, Orion, is low in the east-southeast at 9 p.m.  Above it is Taurus the bull.  The bright orange star in Taurus is Aldebaran.  Aldebaran appears at the bottom left tip of a letter V group of stars lying on its side that is the face of the bull.  Aldebaran isn’t actually part of the group, called the Hyades star cluster.  The cluster is about 151 light years away, while Aldebaran is a bit less than half that.  The star has an orange hue because its surface is cooler than the Sun’s.  However Aldebaran is 44 times larger in diameter, and shines 350 times brighter than the Sun.  Next Monday night the 12th, the Moon will pass in front of Aldebaran in an event called an occultation I’ll have more information on it then.  The name Aldebaran means The Follower, since it follows the Pleiades across the sky as the Earth rotates.

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

Addendum

Aldebaran

Aldebaran in the ‘V’ shape of the Hyades (The face of Taurus the bull) with the Pleiades above. Created using Stellarium.

12/07/2016 – Ephemeris – Where are the bright planets

December 7, 2016 Leave a comment

Ephemeris for Wednesday, December 7th*.  The Sun will rise at 8:06.  It’ll be up for 8 hours and 55 minutes, setting at 5:02.  The Moon, at first quarter today, will set at 1:16 tomorrow morning.

In the east-southeast before 7:30 these mornings. Jupiter can be glimpsed in the morning twilight.  Jupiter will rise tomorrow at 3:01 a.m.  We are approaching Jupiter as it appears to move away from the Sun.  We will pass it on April 7th next year.  Venus and Mars are in the evening sky. At 6 p.m. these planets will be seen in the southwest and low in the sky.  Venus will be the lower and brighter of the two, Mars will be higher to the left.  Venus will set at 8:14.  Mars will hang on a bit longer and will set at 10:10.  Mars’ setting time hasn’t changed much in the last month and a half.  It’s losing to the Sun by only a little bit each day.  Venus is slowly heading northward for the rest of it’s evening appearance, and is moving higher in the sky.

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

* 75th anniversary of the attack on Pearl Harbor.  I was only 3 days old at the time, so had nothing to do with it.

Addendum

Evening Planets

Venus, Mars and the Moon at 6 p.m., December 7, 2016. This is approximately one hour after sunset. Click on image to enlarge. Created using Stellarium.

 

The Moon

A closeup of the Moon at 6 p.m., December 7, 2016. Created using Stellarium.

Jupiter in the morning

Jupiter and a preview of spring constellations at 6:30 a.m. December 8, 2016. Click on image to enlarge. Created using Stellarium.

Jupiter and moons

Jupiter and moons at 6:30 a.m. December 8, 2016. Europa is in Jupiter’s shadow at this time. It will disappear in its shadow at 4:46 a.m. (9:46 UT). Image created using Cartes du Ciel. Note that Europa was on the image, but was removed. Stellarium had it right, but I prefer Cartes’ rendering.

Planets and Moon at sunset and sunrise of a single night

Planets and Moon at sunset and sunrise of a single night starting with sunset on the right on December 7, 2016. The night ends on the left with sunrise on December 8. Click on image to enlarge. Created using my LookingUp program.

Note that Saturn is practically plotted on top of the Sun.  It will be in conjunction with the Sun on the 10th.  After that it will enter the morning sky.

12/06/2016 – Ephemeris – Capella the northernmost first magnitude star

December 6, 2016 Leave a comment

Ephemeris for Tuesday, December 6th.  The Sun will rise at 8:05.  It’ll be up for 8 hours and 56 minutes, setting at 5:02.  The Moon, 1 day before first quarter, will set at 12:08 tomorrow morning.

A bright star called Capella has slowly been rising in the northeastern sky in the evenings for the past few months.  At 8 p.m. now it is low in the east-northeast to the upper left of Orion, rising in the east.  This winter Capella will be overhead, the highest of winter’s seven brilliant first magnitude stars.  Capella never quite sets for anyone north of Ludington.  Due to its brightness, and being the closest first magnitude star to the pole, Capella appears to move slowly as the earth rotates, and spends summer and autumn evenings close to the horizon, and has, in years past, elicited a few phone calls and other queries about that ‘bright object in the northeast’.  Capella belongs to the pentagonal constellation of Auriga the charioteer.

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

Addendum

Capella

The star Capella with the other stars and constellations of Winter rising in the east. Created using Stellarium.

12/05/2016 – Ephemeris – The planet’s name is Dagon

December 5, 2016 Leave a comment

Ephemeris for Monday, December 5th.  The Sun will rise at 8:04.  It’ll be up for 8 hours and 57 minutes, setting at 5:02.  The Moon, 2 days before first quarter, will set at 11:02 this evening.

The lonely bright star low in the south-southwest at 8 p.m. these evenings is Fomalhaut the harbinger of autumn in my book, and about to leave as winter approaches.  Fomalhaut means fishes mouth and is located at the head of Piscis Austrinus, a very dim constellation.  Fomalhaut is a young white star only about 400 million years old with a disk of dust surrounding it.  Near an outer dust ring, 14 years ago the Hubble Space Telescope discovered a spot.  Four years later astronomers discovered that the spot moved along the dust lane and announced the first direct discovery of an exoplanet.  In 2010 and 2012 the planet now dubbed Fomalhaut b or Dagon was observed again and it really does orbit Fomalhaut in a very eccentric orbit.

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

Addendum

Fomalhaut b

The track of observations of Fomalhaut b or Dagon in 2004, 2006, 2010 and 2012. Credit: NASA and ESA.

12/02/2016 – Ephemeris – My talk about the Star of Bethlehem is tonight

December 2, 2016 Comments off

Ephemeris for Friday, December 2nd.  The Sun will rise at 8:01.  It’ll be up for 9 hours and 1 minute, setting at 5:03.  The Moon, 3 days past new, will set at 8:02 this evening.

This evening at 8 p.m. I will be giving a talk investigating the origin of the Star of Bethlehem.  This will be during the monthly meeting of the Grand Traverse Astronomical Society, at Northwestern Michigan College’s Rogers Observatory located south of Traverse City on Birmley Road.  The talk is a scientific treatment of the subject, rather than a religious one.  We’ll look at what the Gospel writers got right and possibly got wrong.  We’ll look at historical writings and oriental observations of the heavens around that time.  This will be augmented by computer simulations of what might be important celestial events visible around that time.  There is no admission charge.  There will be viewing of the skies afterward if it’s clear.

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

Addendum

The Star of Bethlehem: The case for a 2 BC Nativity date

By Bob Moler

This is a 2016 rewriting of a Stellar Sentinel article from December 1997 as an introduction to my talk this month: In Search of the Star of Bethlehem.

At this month’s meeting of the society I will present again the two thousand 2,000 year old search for the Star of Bethlehem. After studying and dismissing, for a variety of reasons, other phenomena, the quest centers on two rare sets of conjunctions of planets. The first, the favorite of the last 400 years, involves a rare triple conjunction of Jupiter and Saturn over 6 months in 7 BC. It’s 2,000th anniversary was in 1994.

The triple conjunction fits if King Herod the Great died in 4 BC. Remember according to Matthew the Magi visited Herod in Jerusalem, and were directed to Bethlehem. According to the Jewish Historian Flavius Josephusi, a contemporary of the Gospel writers, Herod died between an eclipse of the Moon and the following Passover. Pretty much the accepted eclipse was a slight partial eclipse on the early morning of March 13, 4 BC. Passover followed the next lunar month later. It turns out that Josephus was a busy boy in his last dayes after the eclipse. A much better eclipse was that of January 10, 1 BC which was total and visible in the evening, and which allowed a span of 3 months for Herod to accomplish the requisite wickedness of his final days. It is this eclipse, and Herod’s death in 1 BC that the events of the 2 BC Nativity date was based.

The second solution involves the planets Jupiter and Venus, which had two nearly stellar conjunctions 10 month’s apart in 3 and 2 BC, 2,000 years ago from 1998 and 1999. If you’re a bit confused about the mathematics of the 2,000 year subtraction, remember there was no year zero, 1 BC was the year prior to AD 1. So mathematically year -1 was 2 BC. Of course the AD/BC calendar numbering wasn’t used back then. Our calendar wasn’t determined for another 500 plus years later. Back then, the Roman calendar (AUC) was in use in the that part of the world.

Adding to the information on the second solution I talked about 20 years ago are more ideas that were graciously sent me by George Petritz. It was an issue of Imprimis, a publication of Hillsdale College. In the December 1996 issue was an article The Star of Bethlehem by Dr. Craig Chesterii, who suggests the 1 BC date for Herod’s death.

It looks like the Star of Bethlehem was not the spectacular apparition we celebrate today in images and song. The importance of the apparition was definitely in the eye of the beholder. And the beholders were the Magi, astrologer priests of the Zoroastrian religion based in Persia. They have worked out the meaning of every planet, position and constellation in the visible heavens, and they were aware of the writings and religions of the nations that surrounded them. So let’s try to see what the Magi might have read into two planetary conjunctions occurring 10 months apart in 3 and 2 BC.

On August 12th of 3 BC. just before dawn. The two brightest planets Jupiter and Venus merge into a single dazzling star in the dawn twilight. This even occurred below the chin of the constellation of Leo the lion. In the twilight, on the lion’s bright star Regulus was visible.

So here’s the cast of characters. Jupiter then as now was the king of the gods. In Hebrew, it was Sedeq, which meant Righteousness. The Jews worshiped one God, the only God, who created everything, so they didn’t need to see Jupiter as a god.. Venus was the fertility goddess to all except the Jews. To the Babylonians it was Ishtar. However the in Second Kings and Jeremiah the prophets were distresses to find many Jews were indeed worshiping Ishtar. The lion was the king of beasts, and in Genesis 49:9 Jacob associated his son Judah with a young lion. King David was of the tribe of Judah, and so was the Messiah to be. The reference is again repeated in Revelation 5:5, which reveals the power of the association in the early Christian era. Regulus’ name means little king star, an allusion to its location in heart of the king of beasts. The ancients thought that this star ruled the affairs of the heavens.

Beside the conjunctions of Jupiter and Venus, each planet has their own conjunctions of Regulus. Chester also suggests a solution to the problem of the verse in Matthew 2:9, where the star came to a standstill over place where the child was. This seems to be impossible for an astronomical object. Chester’s explanation was that this is when Jupiter reached its stationary points at the beginning and end of its retrograde or westward motion. Well, let’s see the chronology of all these events, as modeled with the free app Cartes du Ciel:

  • August 12, 3 BC. – Venus and Jupiter are in their first conjunction, visible low in the eastern twilight before sunrise. Both are moving eastward against the stars.
  • August 17, 3 BC. – Venus and Regulus are in conjunction.
  • August 24, 3 BC – Venus and Mercury are in conjunction
  • September 14, 3 BC. – Jupiter and Regulus are in conjunction.
  • November 27, 3 BC. – Jupiter is stationary, and will begin to move in retrograde with respect to the stars, or to the west.
  • February 16, 2 BC. – Jupiter and Regulus are in conjunction for the second time, as Jupiter continues the retrograde motion.
  • March 29, 2 BC. – Jupiter is stationary, ending retrograde motion, and resuming its prograde or eastward motion.
  • May 9, 2 BC. – Jupiter and Regulus are in conjunction for the third time.
  • June 10, 2 BC. – Venus and Regulus are in conjunction.
  • June 17, 2 BC. – Venus and Jupiter are in conjunction. They appear to merge into a single star low in the west at sunset.

The first conjunction, on August 12th, 3 BC., apparently set the Magi on their journey. This is the first appearance of the star as recorded in Matthew 2:2. I expect that the knowledge of planetary motions allowed the Magi to predict the second conjunction 10 months later. They may have timed their journey to arrive around that second conjunction.

The Magi expecting a king, went to the capitol city of Judea, Jerusalem. It is a reading from the scriptures that sends them to King David’s birthplace, Bethlehem. As they left Jerusalem the Magi saw the star again. Was this the second conjunction on June 17th, 2 BC?

The problem of the star standing still over where the child was is still there. If the stationary point of Jupiter is that phenomenon, Jupiter would have reached its stationary or standstill point for the last time a month before the Magi ever got to Jerusalem. The stationary position of Jupiter, will be lost on all but keen watchers of the heavens. Jupiter would still share the stars daily motion through the sky. Another point: Jupiter isn’t the star but the combination of Jupiter and Venus is. I’m afraid the standstill problem is still unsolved.

Recently we have had a repeat of the above celestial events in our skies beginning with a close Venus-Jupiter conjunction on August 18, 2014 with a second conjunction on June 30, 2015. These were close conjunctions, though not as close as the ones in 3 and 2 BC, plus they were also seen against the stars of Leo.

Whether this is the Star, or not, we know it was the light of the star that drew the Magi. Today both Christians and Jews celebrate, in this season of darkness and the longest nights, holidays of light with Christmas and Hanukkah.


i Antiquities of the Jews – Book XVII Chapters 6-8

ii A condensed copy can be found on the Internet at http://www.theosophy-nw.org/theosnw/world/christ/xt-star.htm