Last December 13, I went to the PAGASA Astronomical Observatory in U.P. Diliman to observe the peak of the 2010 Geminid Meteor Shower with my amateur astronomy group, the University of the Philippines Astronomical Society (U.P. AstroSoc).
When I came at around 11:00 PM, about 50 people were already at the Sun Deck of the observatory. Everyone was enthusiastically waiting for the bright Geminid meteors despite the growing chance of an overcast sky. The other guests set up their personally-owned telescopes to view the Great Orion Nebula and other deep-sky objects not blocked by clouds.
Amidst the 40% cloudy sky, the constellation Gemini where the meteors seemed to radiate from could be seen at ~40 degrees above the northeastern horizon. In the west, bright Jupiter and the First Quarter Moon were already about to set. The pair looked beautiful as they went lower in the horizon and become partially covered behind the tree tops.
As moonlight disappeared, the sky become darker and more favorable for meteor watching. Four big and bright fireballs zoomed across the sky before midnight. 😀 Unlike other meteor showers, the Geminids can appear almost anywhere in the night sky, making them fairly easy to spot.
However, this short-lived outburst was soon replaced with an overcast sky which lasted until about 2:00 AM. During this time, I took the chance to go online and update my twitter status regarding our observation (I was able to do this thanks to Sun Broadband plug-it!). Several groups locally and internationally were also sharing their meteor counts and meteor watching experience. Below is a screenshot showing some of my tweets during that time.
As what I have noted there, the Observation and Instrumentation Cluster (ObsIn) of U.P. AstroSoc kept a record of the tally* of the number of meteors seen every hour during the Geminids observation.
Limiting Magnitude**: ~4.0
Dec. 13, 2010
22:00 – 23:00 —— 27
23:01 – 24:00 —— 29
Dec. 14, 2010
00:01 – 01:00 —– overcast sky
01:01 – 02:00 —– overcast sky
02:01 – 03:00 —– 20 (with one green fireball!)
03:01 – 04:00 —– 2
04:00 – 05:00 —– 0
prepared by: Francis Bugaoan and Carlo Selabao
* This report just shows the number of meteors seen.Values listed above are the max. number of meteors observed within each time frame which means that it includes all meteors seen by at least one person. These are not the computed Zenithal Hourly Rate (ZHR) of the meteor shower.
** This is used to evaluate the quality of observing conditions. It tells the magnitude of the faintest star visible to the unaided eye
By around 2:00 AM, clouds began to moved away which allowed us to continue on our meteor counting. One green fireball which crossed the northwest sky appeared like a falling big blob of light. 😀 Everyone cheered happily upon seeing it. It lasted for about 5 seconds before disappearing into view.
More than an hour later, Venus which is now a “morning star” lit up the eastern horizon together with Saturn, Spica and Arcturus. Gemini was then past the zenith while my favorite Winter Triangle was already in the west.
Because of this beautiful pre-dawn sky, U.P. AstroSoc members took the opportunity to lead the guests into a star-hopping activity to familiarize them with these celestial objects and the constellations.
As sunrise approached, one member noticed a rarely seen atmospheric phenomenon called the Belt of Venus. It is an arch of pinkish band above the shadow that Earth casts on the atmosphere opposite the sunrise or sunset. It is best visible when the atmosphere is cloudless, yet very dusty, just after sunset or just before sunrise. The arch’s pink color is due to backscattering of reddened light from the rising or setting Sun.
We finished our observation at around 6:00 AM. A lot of the guest observers who came by told us that they enjoyed the meteor counting, as well as the stargazing activities and they’re looking forward to the next meteor shower observation.
Despite the cloudy weather, I was surprised that the Geminids still gave us a fairly spectacular cosmic show. Truly, this shower never fails to live up its reputation as the best meteor shower.
It’ Geminids season again! 🙂
Join the University of the Philippines Astronomical Society (UP AstroSoc) as it observes the 2010 Geminid Meteor Shower at its peak on the night of Dec. 13 until dawn of Dec. 14, at the PAGASA Observatory Sundeck in U.P. Diliman, Quezon City. Click on this page to RSVP and also to see a map showing the location of the observation site.
The Geminids is described by the International Meteor Organization (IMO) as “one of the finest, and probably the most reliable, of the major annual showers presently observable”, and this year’s shower is set to put on a good show.
The Geminid meteor shower active from Dec. 7 until Dec. 17. Unlike many meteor showers, you can start watching for the Geminids around 9 to 10 p.m. – in years when the moon is out of the sky. The First-Quarter Moon interferes during the evening hours this year, and doesn’t set till around midnight. However, this shower tends to gain strength after midnight and to climax at roughly 2 o’clock in the morning, after moonset and when the shower’s radiant point is highest in the sky.
Meteors or “falling stars” can be seen at an average rate of sixty meteors per hour under a dark and cloudless night.
Studies of past displays show that this shower has a reputation for being rich in slow, bright, graceful meteors and fireballs as well as faint meteors, with relatively fewer objects of medium brightness. Many appear yellowish in hue. Some even seem to form jagged or divided paths.
If you trace the paths of all the Geminid meteors backward, they appear to radiate from the same point in front of Gemini. This point is called the meteor shower radiant, and is located near the star Castor. To see Castor, look fairly low in the east-northeast sky around 9 p.m. Castor and the Geminid meteor shower radiant swing upward through the night, and climb pretty much overhead by around 2 a.m. Here’s what is important about a meteor shower’s radiant point: the higher the radiant rises into in your sky, the more meteors you’ll likely to see. That means you can expect to see the most Geminids around 2 a.m., when Castor will be highest in the sky, and the meteors will be raining down from overhead.
But you don’t have to find the meteor shower radiant to see the Geminid meteors, for these meteors shoot all over the sky.
Most meteor showers come from comets, which spew ample meteoroids for a night of ‘shooting stars.’ The Geminids are different. The parent is not a comet but a weird rocky object named 3200 Phaethon that sheds very little dusty debris—not nearly enough to explain the Geminids.
Also on Dec. 13, Mercury and Mars will appear closest (1° apart) while very low in the southwest after sunset. A pair of binoculars would help you see these two objects better. Jupiter and Uranus could as well be seen just 10 degrees away from the First Quarter Moon.
This event is open to all. Bring your family and friends and enjoy the most spectacular meteor shower of the year. 🙂 You won’t need binoculars or a telescope, the naked eye is usually best for seeing meteors.
Clear skies and happy viewing!
poster by Aaron Misayah of UP AstroSoc
The thin waxing crescent Moon (1.8% illuminated) shared the western sky with the planet Mercury (not visible due to the thick clouds) at dusk last December 7, 2010.
Every 29 1/2 days, the Moon completes one lunar cycle (new moon to new moon) in its orbit around the Earth. For the last few days of the cycle we have an “old moon” and then just after New Moon we have the chance to see a “young moon”, a very thin crescent moon, just like this one, above the horizon after the Sun goes down.
Image taken from the PAGASA Astronomical Observatory Sundeck at 6:54 PM PST using my 8.0 megapixel Kodak C813 digital camera.
The University of the Philippines Astronomical Society (U.P. Astrosoc) will be holding its public observation of the 2010 Orionids Meteor Shower on October 21, 6PM (until 6AM of the following day) at the PAGASA Astronomical Observatory Sun Deck in the U.P. Diliman.
This event is for everyone. 😀
The Orionids meteor shower usually reaches its peak around October 21, having an average of 20 meteors per hour. The Orionids are fast meteors and also have fireballs. These meteors radiate near the boundaries between the Great Hunter Orion and Gemini. Orion will rise high late at night and the moon will be near full. Orionids will be best watched after moonset and before dawn.
Also, get a chance to see the beautiful green comet, 103P/Hartley which has been a brilliant target for backyard astronomers this month. This comet provides naked eye visibility in some parts of the country under normal dark sky condition. But this week this beautiful visitor will be in closest approach, crossing within 11 million miles of earth. It could be best spotted during predawn hours near the bright star Capella in the constellation Auriga.
Bring your friends and your wish list, and have fun counting meteors!
Clear skies! 😀