The northern lights in the south usually reveal their beauty in a rare, red glow.  All-red auroras appear at times when intense geomagnetic storms hit the Earth, but are not fully understood.

On March 13, 1989, a massive CME slammed into Earth.  The solar storm this collision caused was called “The Quebec Blackout Storm”, and was seen as far south as Florida and Cuba.   The majority of people in the Northern Hemisphere had never seen such a spectacle in recent history.  The aurora from this storm was visible here in San Antonio as well, even from within the light dome, as a strong red glow in the north.

The media considered the spectacular aurora to be the most newsworthy aspect of the storm.  However, electrical ground currents created by the magnetic storm found their way into the power grid of the Hydro-Quebec Power Authority and the entire Quebec power grid collapsed. Six million people were affected as they woke to find no electricity to see them through a cold Quebec wintry night. This storm could easily have been a $6 billion catastrophe affecting most US East Coast cities.

The striking view of the aurora, shown below, was recorded from a site near El Paso, Texas and the Hueco Tanks State Historical Park on  15 September 2000 at a latitude just under 32° north. Polaris is the brightest star visible near the top and right of center while a Perseid meteor pierces the auroral glow left of picture center, below the bowl of the little dipper.

On August 28, 1859 a massive solar storm, called the Carrington Event, was the most powerful solar storm in recorded history. It occurred during solar cycle 10 and caused spectacular aurora seen all over the world even as fas south as  the Caribbean; also noteworthy were those aurora over the Rocky Mountains that were so bright that their glow awoke gold miners, who began preparing breakfast because they thought it was morning.

Telegraph systems all over Europe and North America failed. Telegraph pylons threw sparks and telegraph paper spontaneously caught fire. Some telegraph systems appeared to continue to send and receive messages despite having been disconnected from their power supplies.

Ice cores suggest that such a blast of solar particles happens only once every 500 years, but even the storms every 50 years could fry satellites, jam radios and cause coast-to-coast blackouts.

One of the many reports came from Galveston:
August 28 as early as twilight closed, the northern sky was reddish, and at times lighter than other  portions of the heavens.  At 7:30 PM a few streamers showed themselves. Soon the whole sky from Ursa Major to the zodiac in the east was occupied by the streams or spiral columns that rose from the horizon. Spread over the same extent was an exquisite roseate tint which faded and returned. Stately columns of light reaching up about 45 degrees above the horizon moved westward. There were frequent flashes of lightning along the whole extent of the aurora. At 9:00 PM the whole of the streaking had faded leaving only a sort of twilight over the northern sky.”

To view an aurora from here in South Central Texas, check with one of the space weather sites, such as SpaceWeather.com, on a regular basis for CMEs heading our way.  Aurora are best seen away from the city lights, but if we get a strong storm, like the one in 1989, lights may not be a problem.

Aurora in Texas is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

By presenting three objects in each of several different groups, the hope is to provide all observers, no matter what their experience level, no matter what type of instruments they have access to, challenging objects to observe. There is even a group for the one instrument we are all born with, the naked-eye. Astrophotographers and astroimagers are not ignored here, either.

No matter what your experience, no matter what you use to observe, get outside and “Keep looking up!”

February’s Sky Challenges

Naked-Eye Challenges

• Barnard’s Loop, also known as Sharpless 2-276, is an emission nebula in the constellation of Orion. It is part of a giant molecular cloud which also contains the bright Horsehead and Orion nebulae. The loop takes the form of a large semi-circular arc some 14° across. It is thought to have been created about 2.5 million years ago by a series of supernoavae that also gave rise to several runaway stars, including AE Aurigae, Mu Columbae and 53 Arietis. The stars within the Orion Nebula are believed to be responsible for ionizing the loop.You will need dark, cloudless, and transparent skies and may benefit from using a nebula filter to see this diffuse nebula.
• The Pleiades or M45. This well known open cluster lies in the constellation of Taurus. It is about 100′ across and contains about 100 stars. Why, you are wondering, is this easy to find object in the challenge list? Well, the six bright stars are fairly easy to see: Atlas, Alcyone, Maia, Taygeta, Electra, and Merope. The challenge here is to view Asterope, Caleano, Pleione, 18 Tauri, HIP 17776, and HIP17900.
• The third member of this month’s naked-eye challenges is to view the Andromeda Galaxy from inside of Loop 410 in San Antonio. A good place to try this would be at the February meeting of the San Antonio Astronomical Association at Christ Lutheran Church of Alamo Heights.

Binocular Challenges

• M33 is a very large, very dim spiral galaxy in Triangulum. M33 is the third largest member of the Local Group of Galaxies. It is small compared to its big apparent neighbor, the Andromeda galaxy M31, and to our Milky Way galaxy, but by this more of average size for spiral galaxies in the universe. One of the small Local Group member galaxies, LGS 3, is possibly a satellite of M33, which itself may be a remote but gravitationally bound companion of the Andromeda galaxy M31. M33 is approaching the Milky Way at 24 km/sec.The Triangulum galaxy is of type Sc, and is a “late” representative of that type of galaxy so it is classified as an Scd. The pronounced arms exhibit numerous reddish HII regions, including NGC 604, as well as blueish clouds of young stars. Population II stars and globular clusters have been found. Although no supernovae have yet been detected in the Triangulum galaxy, several supernova remnants have, and were cartographed by radio astronomers with high acuracy. At least 112 variables have been discovered in M33, including 4 novae and about 25 Cepheids. A strong X-ray source is also situated in this galaxy.
• NGC 2354, an open cluster in Canis Major. It has an apparent diameter of 20′, it is round, and composed of relatively bright stars and a sprinkling of fainter stars. The center seems empty, with very few stars.
• The open cluster Collinder 70. It is about 150′ across and contains about 100 stars, including Orion’s Belt Stars. How many stars can you find?

Small Telescope Challenges

For 2″ to 6″ telescopes:
• Observe the Sun. You will need a solar filter for this one. Please review Sky & Telescope‘s article on Viewing the Sun Safely before attempting to view the Sun. Never, ever look at the Sun without a solar filter!
• Winter Alberio (HD 56577), a binary star in Canis Major lying about 1.6° north of τ Canis Majoris and 0.5° west (2000.0 coordinates are: R.A. 7h 16m 36.8s, Dec. -23 deg. 18′ 56″). This colorful pair has an orangish primary and a blue-white secondary.
• Arp 336, also know as NGC 2685, an edge-on galaxy in Ursa Major, with an apparent  size of 4.5′ by 2.4′.

Medium Telescope Challenges

For 8″ to 14″ telescopes:
• The globular cluster, G1. G1 or Mayall II is located about 2.9 million light years away in the Andromeda Galaxy.
• Leo I, also known as the Regulus Galaxy. This dwarf spheroidal galaxy is a member of the Local Group of Galaxies and is a companion of the Milky Way. It is fairly bright at magnitude 9.8 and large, 9.8′ x 7.4′, but is only 12′ from Regulus making this a difficult object to view.
• Asteroid (26591) Robertreeves, formerly 2000 ET141

Large Telescope Challenges

For 16″ and larger telescopes:
• Split Sirius
• NGC 2285/NGC 2288/NGC 2289 are three faint spiral galaxies in Gemini that lie within 7′ of each other.
• J 900 or PK 194+2.1 is a starlike planetary nebula that lies some 3° west-northwest of γ Geminorum.

Astrophotography/Imaging Challenges

• Novice: Star Trails
  
• Intermediate: IC2177 – Seagull Nebula
  
• Expert: B33/IC434 – The Horsehead Nebula
  

February’s Sky Challenges is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

Nine years ago today, February 1, 2003, the Space Shuttle Columbia was returning from a routine research mission to study microgravity and Earth science with a multitude of international scientific investigations conducted continuously during its 16 days in orbit, when it disintegrated over Texas and Louisiana.  Although the flight path took it over North Texas, it was still visible from San Antonio.  What I and other South Central Texans witnessed was several trails instead of just one.  I knew that something was amiss and went back into the house and turned on CNN.

The loss of Columbia was a result of damage sustained during launch when a piece of foam insulation the size of a small briefcase broke off from the Space Shuttle external tank under the aerodynamic forces of launch. The debris struck the leading edge of the left wing, damaging the Shuttle’s thermal tiles, which shields it from the intense heat generated from atmospheric friction during re-entry.  While Columbia was still in orbit, some engineers suspected damage, but NASA managers limited the investigation, on the grounds that little could be done even if problems were found.0

During re-entry of STS-107, the damaged area allowed the hot gases to penetrate and destroy the internal wing structure, rapidly causing the in-flight breakup of the vehicle. The debris field stretched from Nevada to Louisiana with the majority of the debris found in Texas, Louisiana, and Arkansas.

In remembrance of the 17 brave men and women who gave their lives making the dream of spaceflight a reality:

Apollo 1
Virgil I. “Gus” Grissom, Command Pilot
Edward H. White II, Senior Pilot
Roger B. Chaffee, Pilot

STS-51L
Francis R. Scobee, Commander
Michael J. Smith, Pilot
Judith A. Resnik, Mission Specialist
Ronald E. McNair, Mission Specialist
Ellison S. Onizuka, Mission Specialist
Gregory B. Jarvis, Payload Specialist
Sharon Christa McAuliffe, Payload Specialist (Teacher in Space)

STS-107
Rick D. Husband, Commander
William C. McCool, Pilot
Michael P. Anderson, Payload Commander
David M. Brown, Mission Specialist
Kalpana Chawla, Mission Specialist
Laurel Blair Salton Clark, Mission Specialist
Ilan Ramon, Payload Specialist

What were you doing when the Columbia was lost?

Columbia is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

Twenty six years ago I was on my way to class when I decided to watch the the Challenger launch at the Student Lounge in the Science Building at the University of Texas at San Antonio.  Little did I know that the two dozen students in the lounge and myself would be among the relatively few Americans who actually saw the Challenger break apart live on CNN 73 seconds into its flight

Yes, I said “break apart”. The Challenger did not explode, at least in the in the conventional definition of that word. There was no shock wave, no detonation, no “bang”. Witnesses on the ground reported they just heard the roar of the engines stop. When the right solid rocket booster (SRB) began to leak, lateral thrust was added causing the Challenger to begin to turn. The stress on the fuel tank caused it to crumple, spilling liquid oxygen and hydrogen which formed a huge fireball at an altitude of 46,000 ft. Both SRBs climbed up out of the cloud, still firing and unharmed by any explosion. Challenger itself was torn apart as it was flung free of the fuel tank and SRBs and turned sideways at Mach 2. Several individual propellant tanks were seen exploding, but the spacecraft had already broken apart by that point.

Pieces of Challenger continued ascending until they reached an altitude of 65,000 feet and began to fall back to Earth. The crew cabin was intact after the breakup and hit the water at 200 mph 2 minutes and 45 seconds after the break up and the crew survived the break up. The impact generated a force around 200 G’s

On the night of the disaster, President Ronald Reagan had been scheduled to give his annual State of the Union address. He postponed the State of the Union address for a week and instead gave a national address on the Challenger disaster from the Oval Office of the White House. What is most remembered from his address was the quoted from the poem “High Flight” by John Gillespie Magee, Jr. at the end of the address:

Three days later, Reagan and his wife Nancy traveled to the Johnson Space Center in Houston to speak at a memorial service honoring the astronauts where he stated:

Do you remember where you were when the Challenger was lost?

Challenger is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

It was 44 years ago today that a fire in the cabin during a launch pad test  at Launch Pad 34 at Cape Canaveral killed all three crew members – Command Pilot Virgil “Gus” Grissom, Senior Pilot Edward H. White and Pilot Roger B. Chaffee – and destroyed the Command Module.

Appollo 1 was scheduled to be the first manned mission of the Apollo manned lunar landing program, with a target launch date of February 21, 1967.  The mission name Apollo 1, chosen by the crew, was officially retired by NASA in commemoration of them on April 24, 1967.

Immediately after the fire, NASA convened the Apollo 204 Accident Review Board to determine the cause of the fire. Although the ignition source was never conclusively identified, the astronauts’ deaths were attributed to a wide range of lethal design and construction flaws in the early Apollo Command Module. The manned phase of the project was delayed for 20 months while these problems were corrected.

My family visited KSC in late spring/early summer that year and the Saturn 1b booster was still on Launch Pad 34.  Do you remember where you were?

Apollo 1 is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

Update: Analysts at the Goddard Space Weather Lab say the CME should reach Earth on 24  January at 14:18 UT (+/- 7 hr) and Mars a little more than a day later.  Strong geomagnetic storms are possible when the cloud reaches Earth.  Our magnetic field is still reverberating from a CME impact on Jan. 22nd, so another blow could spark impressive auroras at high latitudes.  Sky watchers in northern Europe, Canada, Alaska, and northern-tier US states such as the Dakotas, Minnesota and Wisconsin should be alert for Northern Lights.

This morning, 23 January, around 0359 UT, following on the heels of yesterday’s coronal mass ejection’s (CME) collision with Earth, large sunspot 1402 erupted, producing a long-duration M9-class solar flare. The explosion’s M9-ranking puts it on the threshold of being an X-flare, the most powerful kind. NASA’s Solar Dynamics Observatory captured the flare’s extreme ultraviolet flash:

The Solar and Heliosphere Observatory (SOHO) and the STEREO-Behind spacecraft have both detected a CME rapidly emerging from the blast site. Analysts at the Goddard Space Weather Lab estimate a velocity of 2200 km. There is little doubt that the cloud is heading in the general direction of Earth. A preliminary inspection of SOHO/STEREO imagery suggests that the CME will deliver a strong glancing blow to Earth’s magnetic field on 24-25 January as it sails mostly north of our planet.

Arriving a little later than expected, a CME hit Earth’s magnetic field at 0617 UT on 22 January. According to analysts at the Goddard Space Weather Lab, the impact strongly compressed Earth’s magnetic field and briefly exposed satellites in geosynchronous orbit to solar wind plasma. Shifting lines of magnetic force induced strong ground currents in Norway and sparked bright auroras over the upper reaches of North America. This colorful corona appeared over Chatanika, Alaska:

And this appeared over Tromsø, Norway:

While aurorae are extremely rare in San Antonio, we did experience them during the solar maximum in 1987.  Maybe as we approach the solar maximum in 2013 we’ll get the opportunity again.  In the meantime, if you have access to the proper equipment, get out and observe the Sun and the highly energetic sunspots 1401 and 1402.

Remember: Never look at the Sun directly without a solar filter

An Active Sun is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

Sirius B is a white dwarf of type DA2-5 or A2-5 VII. It is 360 times fainter than Sol and compared with our Sun, it has nearly the same mass but less than one percent of its diameter. Sirius B$s diameter of about 11,700 km (about 7,300 miles) is about 92 percent of Earth$s diameter. Its mass and diameter are consistent with the theoretical size for a carbon-core white dwarf, one that may have evolved from a 5 Solar-mass, B-type main-sequence star about 125 million years ago, and after 100 million years as a giant star burned up its supply of hydrogen and threw off its outer layers. So, Sirius B was once brighter than Regulus A, currently a B7 main-sequence star. While now tiny compared to main sequence stars, white dwarf stars are actually intensely hot, but without the internal heat of fusion to keep them burning, they gradually cool and fade away.

The separation of these two stars varies from 3 arc seconds to 11.5 arc seconds over a period of almost 50 years. Under excellent viewing conditions a 60mm refractor can split double stars of similar magnitudes separated by 2 arc seconds. So why is it so difficult to split Sirius with your telescope? The brilliance of Sirius A simply overwhelms the much fainter Sirius B.

So how do you split Sirius? You could use the same technique that Alvin G. Clark used to inadvertently discover the Pup. In January, 1862, Clark was testing a new 18 ½-inch refractor. The telescope was pointed towards the edge of a building where Clark knew that Sirius would be emerging any minute from that position. To his surprise the first star that he saw was the companion, Sirius B. Now you won$t need a huge Clark refractor to see the Pup, again, in theory, a 60mm telescope should be able to split the pair. But, because of the brightness of Sirius A, you will probably need at least a 4″ or 6″ telescope to view Sirius B.

Before you try this method it is helpful to know exactly where Sirius B currently is. If you imagine that Sirius is at the center of the face of a clock Sirius B would be at the 8:45 position. If you are using a refractor or a similar telescope that gives an upright but reversed image the Pup would appear in the eyepiece in the 3:15 position. A slight modification of this method is to center Sirius in the eyepiece and then shift the telescope so Sirius A is just outside the field of view in a position that is 180° away from Sirius B. Or said a different way, move Sirius A out of the field of view on the edge of the field opposite the direction of the tiny white dwarf.

Another method that can be used to observe Sirius and other close multiple star systems is to create a hexagonal mask for your telescope. If you have a telescope with a corrector plate, you simply need to cut a piece of cardboard or project board the diameter of your corrector plate, then inside the circle cut a hexagon, leaving one inch at the vertices. You should glue three 1/2 inch dowell rod tips on the inside of the mask to prevent the mask from scratching your corrector plate and you may want to glue a fourth dowell rod tip to the outside of the mask to act as a handle to make it easier to rotate the mask.

If you have a Newtonian or a refractor, you can omit the inside dowell tips, but you$ll need to add a flange to the edge to secure the mask to your telescope. Something akin to an oatmeal box lid. The hexagon mask will eliminate the airy disks around the bright component and change them to a bright star with six spikes. This simple homemade tool will make it possible to view close and high contrast binary stars.

There is another technique that may prove successful. Set up your telescope before it gets dark. Let the optics cool. Try to find Sirius in the approaching twilight. Keep observing with Sirius in the center of the field as it gets darker. With the brilliance of the Dog Star subdued by the bright sky it is possible to view the Pup.

No matter what method you use to try to split Sirius or other multiple star system, there are several tips which can be very helpful:

1. Know where the secondary star(s) will be in relation to the primary star.
2. Only try to split the stars when the system is on or near the meridian, as nearly overhead as possible. This reduces the amount of atmosphere that the star$s light passes through.
3. Try it only on the steadiest of nights.
4. Use as much magnification as seeing conditions will allow.
5. If one of the stars is intrinsically brighter that the others, move that star out of the field of view in the opposite direction of the dimmer star(s).
6. If you have a telescope with a spider, such as a Newtonian, be sure you don’t have the secondary star(s) aligned with one of the diffraction spikes.

Observing the Pup is not easy. If you don’t succeed at first, don’t give up. The separation between Sirius A and B is about 8 arcseconds and will continue to grow to 11.5 arcseconds in 2025, making it a little easier to see the Pup over the next 17 years.

Viewing the “Pup” is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

[don't censor the web]

SOPA and PIPA is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

By presenting three objects in each of several different groups, the hope is to provide all observers, no matter what their experience level, no matter what type of instruments they have access to, challenging objects to observe. There is even a group for the one instrument we are all born with, the naked-eye. Astrophotographers and astroimagers are not ignored here, either.

No matter what your experience, no matter what you use to observe, get outside and “Keep looking up!”

January’s Sky Challenges

Naked-Eye Challenges

• The constellation Lepus
• Seven or more stars of the Pleiades
• M33

Binocular Challenges

• NGC 2244, an open cluster in the Rosette Nebula in Monocerotis
• NGC 2264, an open cluster of about 40 stars in Monocerotis, also known as the Christmas Tree Cluster
• M46, an open cluster of about 100 stars in Puppis

Small Telescope Challenges

For 2″ to 6″ telescopes:
• Epsilon Monocerotis, a multiple star system consisting of a pale yellow A8 primary, an F5 secondary described as steel blue in color, and a 12th magnitude star about 95″ away
• Melotte 71, an open cluster of about 80 stars in Puppis
• NGC 2539, an open cluster of about 50 stars in Puppis

Medium Telescope Challenges

For 8″ to 14″ telescopes:
• NGC 2438, a planetary nebula in M46 in Puppis
• NGC 2360, an open cluster of about 80 stars in Canis Majoris
• NGC 2509, an open cluster of about 150 stars in Puppis

Large Telescope Challenges

For 16″ and larger telescopes:
• NGC 2337-39, the Rosette Nebula
• NGC 2261, an emission nebula in Monocerotis, commonly called “Hubble’s Variable Nebula”
• NGC 2298, a globular cluster in Puppis

Urban Skies Observing Challenges

• NGC 2438, a planetary nebula in the open cluster M46 in Puppis
• M79, a globular cluster in Lepus/li>
• Comet P/2006 T1 Levy

Astrophotography/Imaging Challenges

• Novice: Star Trails
• Intermediate: Mars
• Expert: B33/IC434 – The Horsehead Nebula

January Sky Challenges is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.

The Star of Bethlehem is a star in Christian tradition that revealed the birth of Jesus to the Magi or wise men and led them to Bethlehem. According to the Gospel of Matthew^[1], the only place in the New Testament mentioning the Star, the Magi were men from the east who were inspired by the appearance of the Star to travel to Jerusalem to search for the “King of the Jews”.^[2] In Jerusalem the Magi met King Herod, who informed them that the child that they were searching for was in Bethlehem. The Magi traveled to Bethlehem, found Jesus and his parents, paid homage to him, presented him with gifts and then returned to the lands from which they came.^[3]

Because the magi told Herod that they saw the star “at its rising”,^[4] it is easy to assume that the Star of Bethlehem is an astronomical object. If the Star of Bethlehem was an astronomical event, it must have been a comet, a nova, a supernova, or a planetary conjunction. To ascertain what astronomical event corresponds to the Star of Bethlehem was, we first need to attempt to determine the date of Jesus’ birth.

Determining the Date of Jesus’ Birth

While there is no historical accounting of the birth of Jesus, we know, from biblical references, that Jesus was born while Herod was King.^[5] Herod reigned between 37 and 4 B.C.E. We also know from biblical accounts that the wise men came to pay respects to the child Jesus,not the newborn Jesus. This conclusion was reached based upon King Herod’s orders to kill every child in and around Bethlehem who were two years old or younger. ^[6]

Jesus was “about” thirty when he began his ministry,^[7] and the books of Matthew, Mark, Luke, John, and Acts of the Apostles, the Jewish author Josephus and the Roman author Tacitus all state that Jesus was killed during the rule of Pontius Pilate, the governor of Judea, C.E. 26 through 36. ^[8][9][10] Also, John the Baptist and Jesus began their ministries around the same time, that is in the fifteenth year of the reign of Emperor Tiberius (C.E. 14-37), when Pontius Pilate was governor of Judea (C.E. 26-36), Herod Antipas was tetarch of Galilee and Perea (4 B.C.E.-C.E. 39), Herod Philip was tetarch of Batanea, Trachonitis, and Auranitis (4 B.C.E.-C.E. 34), and Caiaphas was high priest (C.E. 18-36). This places the date between C.E. 27 and 29.^[11]

So, if Jesus was about thirty in the years C.E. 27 through 29, and was born while Herod was King, and was at least two before Herod’s death in 4 B.C.E., then Jesus was born somewhere between 7 and 5 B.C.E..

We seem to have narrowed down Jesus’ birth year to somewhere between 5 and 7 B.C.E. Since the Magi visited the child Jesus and King Herod ordered the deaths of all children 2 years and younger, the Magi visit occurred between 4 and 5 B.C.E.

Can we determine at what time of the year Jesus was born? Let’s take a look at the Book of Luke again. Luke records that shepherds were watching over their flocks by night^[12]. There are only two specific times in a year when this was done, namely when lambs were being born in the spring or autumn. At other times of the year they were kept safely in their sheep-folds to protect them from wild animals. So Christmas may be celebrated eight months too late. Without historical documentation it may ultimately be impossible to know the day and month of Jesus’ birth.

These estimates are as close as we can get, without an historically documented event.

Finding an Astronomical Event

The sole unusual event surrounding Jesus’ birth that is mentioned in the Bible is the Star of Bethlehem, so we look to the skies.

What astronomical events occurred in those three years? In 7 B.C.E. there was a triple conjunction of Jupiter and Saturn in Pisces, one in late May, one in late September, and one in early December. A conjunction is when two or more objects appear very close together on the sky. Pisces is associated with the Jewish people in astrology, so when Jupiter and Saturn passed very close to each other three times during the span of several months in 7 B.C.E. it was a notable event. Adding to the significance of this conjunction is that this triple conjunction in Pisces occurs once every 900 years.

In February, 6 B.C.E., Jupiter, Saturn, and Mars passed within 8° of each other in the constellation Pisces. This near conjunction occurs only once every 800 years^[13]. Jupiter was the “star” of royalty and luck. Saturn was the “star” of the Mesopotamian deity who protected Israel. These conjunctions would have been easily predicted by astronomers/astrologers of the time and most likely interpreted as a great king was to be born in Israel.

In March/April of 5 B.C.E. Chinese astronomers recorded a “new” star in the constellation of Capricorn which was visible for over 70 days^[14]. The “new” star could have been a nova or a supernova. A nova is caused by a white dwarf gathering enough material, usually from a nearby companion in a binary system, onto its surface to raise the surface pressure high enough for a thermonuclear explosion. The white dwarf’s increase in brightness may be a factor of 10,000 to over one million. The increase to peak brightness is very rapid, within a few days, while the fading away to invisibility usually takes a few months. A supernova is caused when a star at least 8 times as massive as our Sun reaches the end of its life and suddenly explodes and throws off most of its mass. For a few days a supernova may outshine its host galaxy and will slowly fade away. This “new” star would have been visible in the east, several hours before sunrise.

In May of 5 B.C.E. Jupiter emerged from behind the Sun and passed through a stationary point in September. Jupiter appears stationary for about a week at the beginning and end of a retrograde motion cycle. Could this have been the Christmas Star? Unlikely, the magi were astrologers and would have recognized these events for what they were.

Could the “new” star in March/April of 5 B.C.E. have been a comet? Probably not. The Chinese called comets “broom stars” because of their tails. Although the “new” star could have been a comet with a tail too faint to detect without optical aid, the Chinese astronomers did not report any movement of the “new” star; and as we all know, comets move across the sky^[14]. Halley’s comet made an appearance in 12 B.C.E., but that is outside the probable date range for the birth of Christ.

None of these events seems to fit the Star of Bethlehem very well. But if the assumption is made that the Magi visit occurred when Jesus was between 18 and 24 months old. And that this visit was triggered by a celestial event. The conjunctions of 7 B.C.E. are out of the range of probable dates of the Magi visit. As is the conjunction of 6 B.C.E. It is unlikely that the motions of Jupiter in 5 B.C.E. would have caused astrologers to begin a journey to Bethlehem. This leaves the new star of March and April 5 B.C.E. As the “best fit” to be the “Star of Wonder”.

As to other sources of the Star of Bethlehem, I will leave that to others to ponder. The Star is what it is: a symbol of hope to over a billion people.

References

1. Matthew 2:11
2. Matthew 2:1-2
3. Matthew 2:11-12
4. Matthew 2:2
5. Matthew 2:7-10
6. Matthew 2:12-16
7. Luke 3:23
8. Joseph ben Matthias (Flavius Josephus) 70, The Jewish War
9. Joseph ben Matthias (Flavius Josephus) 93, Jewish Antiquities
10. Tacitus 81, Annals
11. Luke 3:1-2
12. Luke 2:8-9
13. Bulmer-Thomas, Ivor 1992, Quarterly Journal of the Royal Astronomical Society, vol. 33, p. 363.
14. Kidger, Mark, “Chinese and Babylonian Observations”

The Christmas Star is a post from: San Antonio SkyWatch.
Copyright © 2007-2012 by Scott Logan. All rights reserved.