Comet ISON Part II: What To Expect
Saturday, November 02, 2013
Today’s Part II will serve as an ISON observing guide, noting dates, times and locations of where to look in the sky. Should Comet ISON become a very bright comet, and if it survives its very close approach to the Sun, Skyscrapers will hopefully be planning observing opportunities. (Unfortunately due to our tree-obscured northwestern horizon we will not be able to offer comet observing with our telescopes at Seagrave Memorial Observatory in North Scituate.) Keep looking for updates in this news media regarding the location(s) and observing dates and times.
The Comet ISON story began in Russia on September 21, 2012. A faint spec was discovered on images taken with a 16-inch reflector telescope as part of an asteroid search conducted by the International Scientific Optical Network, hence the name of the comet. ISON was also given an official designation of C/2012 S1.
When the orbit and distance were confirmed, it was determined to be approximately 623,000,000 miles from the Earth. Though the comet was still quite faint, original estimates suggested this dirty snowball was up to six miles across. And because it was discovered so far out, beyond Jupiter’s orbit, some astronomers started to use such descriptions like “comet of the century” and will be “brighter than a Full Moon” and “even visible in broad daylight.”
As I mentioned in my comet primer last month, comets do pretty much what they want to do. In fact, the only thing predictable about their behavior is that they are unpredictable.
ISON was initially very bright at its discovery distance because it is believed that this is the comet’s first trip towards the Sun. That means there was a lot of loose material on ISON’s surface. Solar radiation blew this material off into space, making the comet brighten.
However, after a period of time, the comet did not continue to brighten as predicted. The brightening stalled because the surface was most likely blown clean of loose material. By the time ISON got to the H2O turn-on point (where water and other volatiles react to the Sun’s heat and escape through cracks on the comet’s surface), the comet was about two magnitudes (6.3 times) fainter than forecast.
At the end of May, while Comet ISON was still out beyond the orbit of Mars, it was lost to view because it was in the direction of the Sun. When the comet finally moved out of the solar glare and was imaged on August 12, it was still fainter than what was originally forecast. At the time, some comet experts thought it was still too early to make a reliable call on what we could expect to see as ISON neared the Sun. Others simply didn’t believe it would become visible to the naked-eye. And there are those experts who do not believe Comet ISON will actually survive its close passage to the Sun.
Even as I write this column in late-October, I find it difficult to make any definitive predictions for the visibility of Comet ISON. (Remember, comets are quite unpredictable.) ISON has been visible to stargazers with telescopes using star charts or computerized pointing systems to locate the comet in the sky. In time, binoculars may eventually provide a small but recognizable image. Naked-eye views may not be afforded. Only time will tell. For now I will simply relate when and where in the sky you will have the best opportunity to catch a glimpse of Comet ISON.
While advanced amateur astronomers have been imaging ISON for some months, it is now more easily accessible to a casual stargazer with modest telescope equipment. On November 1, you can locate the comet about 22 degrees above the eastern horizon at 5:00 a.m. Don’t expect to see it with the naked-eye. The comet will be about as faint as the planet Neptune. To verify you are in the general area of the sky, you will easily see the red planet Mars residing within the constellation of Leo. ISON will be about seven degrees below and to the left of Mars. Use a wide field eyepiece and slowly scan this region. Comet ISON should display the typical comet shape with a tail of unknown length.
ISON will quicken its movement each morning as it plunges towards the horizon and a rendezvous with the Sun on November 28. At this time it is very hard to predict when the comet will be lost to view, especially since more recent brightness forecasts have ISON much fainter than originally thought. We may lose sight of it a day or two before perihelion (closest point to the Sun).
If ISON survives its close approach to the Sun (within about 700,000 miles of the solar surface), it may briefly brighten as it rises back into the morning sky to begin its journey back into the depths of the solar system. First it will appear just before sunrise very low in the east-south-east. Each morning it will climb higher into the sky and away from the Sun’s glare. Soon ISON might be seen in morning twilight, and then will rise into a darker sky. It’s merely guesswork at this point what may be seen.
Also after perihelion ISON will become visible in the evening sky right after sunset. However, during the first couple of weeks in December ISON will hang very low above the west to north-west horizon. You’ll need an unobstructed view to observe the comet. Originally astronomers were saying the tail would extend many tens of degrees into the sky. That scenario is not likely to happen. I do hope the now pessimistic predictions are wrong. If ISON ends up being a nice, not great, comet visible to the naked-eye, then we’ll all be happy.
As the weeks progress, ISON will begin to rise above the north-western horizon. By December 25, it will still be visible in telescopes as it climbs towards the north. On January 7, it will pass within two degrees (four Full Moon diameters) of Polaris, which shines at magnitude +2. The comet will be about +7 magnitude and not visible to the naked-eye. Binoculars may still show it, but it is mere speculation whether a tail will still be detectable.
After that the comet will even more quickly fade from view and memory.
Please keep in mind the above forecasts are extrapolation from known ISON facts and past comet behavior. Anything can happen.
Should new information come to light during the next few months I’ll be sure to pass them along to the various news outlets so you will have the best opportunity to view Comet ISON.
Since ISON received so much hype after it was discovered, I hope the national news services will keep everyone posted on Comet ISON updates. They can more quickly keep the general public informed should ISON’s viewing prospects change.
Keep your eyes to the skies.
Ten Greatest Days in New England Sports History
February 1, 2004
Patriots 2004 Super Bowl
In 2004, the Patriots captured their third Super Bowl in four years. The win put New England in the group of the small number of dynasty teams in the NFL, joining the Packers, Steelers and 49ers.
Super Bowl XXXVIII finished with the Patriots holding on to a 32-29 win over the Carolina Panthers.
The game was also famous for the infamous wardrobe malfunction involving Janet Jackson and Justin Timberlake.
December 21, 2010
Longest Winning Streak
The UConn women broke UCLA men's streak of the most consecutive wins in a season.
They dominated their sport like no other and on December 21, 2010, UConn's 93-62 win over Florida State put UConn women in the #1 position.
Later, Sports Illustrated named UConn women as the #3 greatest dynasty in sports in the decade behind only the Lakers and Patriots.
June 12, 1984
Celtics v. Lakers
The 1980's were the glory days of the NBA and the Boston Celtics and the Los Angeles Lakers were the two teams that elevated the play and excitement of the era.
Larry Bird and Magic Johnson were the superstars and were the feature players. Their rivalry started in the NCAA finals when Magic dazzled and Bird fizzled.
On June 12, 1984, the Celtics won game seven, 111-102 with Cedric Maxwell leading the Celts in scoring with 24 points and a team leading 8 assists. Bird was MVP of the series.
October 27, 2004
Curse of the Bambino
In 2004, after the dramatic historic come from behind win against the Yankees, the Red Sox went on to the World Series and swept the Cardinals 4-0, to win the first title since 1918.
The World Series win broke the proverbial "Curse of the Bambino" which had been in place since the Red Sox sold Babe Ruth to the Yankees.
November 23, 1984
BC v. Miami
There could not have been a more unlikely superstar and there could not have been a bigger stage to pull off the most dramatic win when BC beat the defending National Champions. Quarterback Doug Flutie put on the best show - maybe ever -- in college football.
Flutie threw for 474 yards and 4 touchdowns and the last TD was to Gerard Phelan on the final play - maybe the most exciting play ever in sports.
Final score: BC 47, University of Miami 45.
October 13, 2013
Patriots Beat New Orleans on Last Second TD; Red Sox Comeback from 5 Runs Down v. Tigers
New England sports fans enjoyed the most improbable double header comeback wins.
First, the Patriots upset the undefeated New Orleans Saints with a 70 yard last minute drive that saw the Patriots score with just 5 seconds to steal a 30-27 win. The Saints had numerous opportunities to put the game away.
Then, the Boston Red Sox in Game Two of the ALCS at home rallied from a 5 run deficit in the 6th inning and came back on a David Ortiz grand slam to tie and a 9th inning hit to win. The Red Sox had lost Game One of the series 1-0 and were on the verge in Game Two of losing any chance of winning the series.
May 10, 1970
Bruins Beat Blues 4-3 in OT to Win Stanley Cup
The Boston Bruins took New England by storm behind the play of Phil Esposito and Bobby Orr.
In the final game and the score tied 3-3, Orr scored the winning and iconic goal to launch the Bruins into the hearts of New Englanders and to create one of sports most memorable photos.
April 28, 1966
Celtics Win 8th Straight, Red's Last Game, Russell First African American Head Coach
The win by the Boston Celtics over the Los Angeles Lakers in 1966 was a triple header for sports.
First, the 1966 Championship was the 8th straight and set a record never to be matched.
Second, it was the last game that Red Auerbach would ever coach.
Third, as Red stepped down, the enigmatic Bill Russell was named player coach - he was the first African American pro coach of the modern sports era. (Brown alum, Fritz Pollard coached pro football).
February 3, 2002
Patriots Upset Rams to Win 1st Super Bowl
The New England Patriots were 14 point underdogs to the Rams and this was expected to be one of the biggest blowouts in Super Bowl history.
Instead, the Patriots played physical defense and although outgained 427-267 in yards, went on to best the Rams.
The Patriots won on a last second field goal to win their 1st Super Bowl by a score of 20-17.
October 20, 2004
Red Sox Come Back from Down 0-3, to Beat Yankees in ACLS
The Red Sox were looking at another sad loss to the New York Yankees three games to zero and down to 3-4 in the ninth inning and down to their last three outs. The Sox scratched a run off a stolen base by Dave Roberts and a clutch hit by Bill Mueller to tie the game 4-4 and send it into extra innings.
In the 12th inning, the Red Sox scored two runs off a walk off homer by David Ortiz.
The Red Sox went on to make history winning three more games.
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