The Geminid Meteor shower of December 13th (Winter’s Fireworks)

Early to mid December is the time for the yearly Geminids meteor shower, so named as its radiant appears to be the constellation Gemini.  First observed only about 150 years ago, the Geminids are thought to be getting more intense each passing year.  The shower is expected to peak around the 13th (next Monday night) this year, with great viewing from the 9th through the 13th.

The Geminids are unusual in that they are not caused by debris from a comet, but from 3200 Phaethon, an Apollo asteroid.  Discovered October 11, 1983, 3200 Phaethon is the first asteroid discovered by a spacecraft, and it approaches closer to the sun than any other numbered asteroid.

The Geminids (also known as Winter’s Fireworks) are somewhat slow moving, bright yellowish in color.  They are considered the most consistently active meteor shower; and this year will offer prime viewing conditions.  The moon will be in its first quarter, setting several hours before sunrise.

Amateur viewers are expected to be able to catch 100  – 120 streaks per hour at the most active times. Expect Earth grazers as Gemini rises, right after sunset, especially on the 13th.  The action should pick up from about midnight until dawn (applicable for all time zones), as Gemini moves overhead.

I have my thermos ready to go!

Total Lunar Eclipse of December 21st

Total Lunar Eclipse

The last lunar eclipse of 2010 is especially well placed for observers throughout North America. The eclipse occurs at the Moon's descending node in eastern Taurus, four days before perigee.

The Moon's orbital trajectory takes it through the northern half of Earth's umbral shadow. Although the eclipse is not central, the total phase still lasts 72 minutes. The Moon's path through Earth's shadows as well as a map illustrating worldwide visibility of the event are shown in the following figure . The timings of the major eclipse phases are listed below. 

The white areas represent where the eclipse will be seen

Penumbral Eclipse Begins:   05:29:17 UT

Partial Eclipse Begins:     06:32:37 UT

Total Eclipse Begins:       07:40:47 UT

Greatest Eclipse:           08:16:57 UT

Total Eclipse Ends:         08:53:08 UT

Partial Eclipse Ends:       10:01:20 UT

Penumbral Eclipse Ends:     11:04:31 UT

At the instant of greatest eclipse (08:17 UT) the Moon lies near the zenith for observers in southern California and Baja Mexico. At this time, the umbral magnitude peaks at 1.2561 as the Moon's southern limb passes 2.8 arc-minutes north of the shadow's central axis. In contrast, the Moon's northern limb lies 8.1 arc-minutes from the northern edge of the umbra and 34.6 arc-minutes from the shadow center. Thus, the southern half of the Moon will appear much darker than the northern half because it lies deeper in the umbra. Since the Moon samples a large range of umbral depths during totality, its appearance will change dramatically with time. It is not possible to predict the exact brightness distribution in the umbra, so observers are encouraged to estimate the Danjon value at different times during totality. Note that it may also be necessary to assign different Danjon values to different portions of the Moon (i.e., north vs. south).

The entire event is visible from North America and western South America. Observers along South America's east coast miss the late stages of the eclipse because they occur after moonset. Likewise much of Europe and Africa experience moonset while the eclipse is in progress. Only northern Scandinavians can catch the entire event from Europe. For observers in eastern Asia the Moon rises in eclipse. None of the eclipse is visible from south and east Africa, the Middle East or South Asia.

The December 21 total lunar eclipse belongs to Saros 125 a series of 72 eclipses in the following sequence: 17 penumbral, 13 partial, 26 total, 9 partial, and 7 penumbral lunar eclipses (Espenak and Meeus, 2009). Complete details for the series can be found at:

eclipse.gsfc.nasa.gov/LEsaros/LEsaros125.html

December 21st's Total Lunar Eclipse

 

This month's picks of the very best astrophotos.

The Crescent Nebula

GORDON HAYNES

HEREFORD, JULY 2010 

Gordon says: "I like the contrast of the blue of the crescent compared to the reddish colours of the surrounding hydrogen clouds, which helps to highlight the different gases present. The wide-field view afforded by my equipment gives more context to the size of the Crescent compared to its surroundings."

Equipment: Takahashi FSQ-106ED refractor with a Starlight Xpress SXVF-H36 CCD camera on a Paramount ME mount.

Sky at Night Magazine says: "The vibrancy of Gordon's imoge is wonderful. We love the great detail seen in the tendrils af faint and tenuous gas surrounding the Crescent."

The Crescent Nebula

 

 

 

 

The North American Nebula

IAN DUNBAR

SALISBURY, AUGUST 2010 

Ian says: "I particularly like the backdrop of a moss of Milky Way stars and the intricacies of the dark dust threads that weave their way through the bright nebulae. It's a beautiful area of the sky."

Equipment: William Optics ZS80FD refractor with a modified and cooled Canon EOS 4500 DSLR camera mounted on an EQ6 mount.

The North American Nebula

 

 

The Moon

PETROS OIAMANTOPOULOS

LOUTRAKI, GREECE, 31 JULY 2010 

Petros says: "I don't usually do any astrophotography when the Moon is up. This time, however, I decided to try something different and used my CCO camera to capture the Moon. After experimenting with various filters and exposure times I took this image through a hydrogen alpha filter."

Equipment: Takahashi TOA-130 refractor and an SBIG ST-2000XM CCO camera on an Astro-Physics 1200GTO mount.

The Moon

 

The Milky Way and the Aurora

FREORIK BROMS

KVALOYA, NORTHERN NORWAY, 23 OCTOBER 2009

Fredrik says: "With this wide-angle shot I wanted to capture the feeling of escaping a light-polluted place. I am very fond of the feeling of silence that I feel I have been able to capture in this image”.

Equipment: Nikon 03 OSLR camera with an AF-Nikon 20mm lens on an AstroTrac TT320X mount.

 

 

The Milky Way and the Aurora

Stars in Motion

MIGUEL CLARO

VILA BOIM, PORTUGAL, 19 JULY 2010

Miguel says: "To record the motion of the stars in the region of the celestial pole, I stocked 328 images, each a 30-second exposure. It was the longest exposure I've done so far, a total integration of 2 hours 44 minutes. The 1ight drawings' were made with a red and while lantern when I passed by."

Equipment: Canon EOS SOD OSLR camera with a Sigma EX HSM 10mm lens.

Stars in Motion

 

Jupiter and moons

MARC DELCROIX

TOURNEFEUIL1E, FRANCE, 8 JULY 2010 

Marc says: "This image is a montage of Jupiter's moons in IR and Jupiter in RGB. From left to right you can see 10, Jupiter, Europa and Ganymede (with Golileo Regia)."

Equipment: Meade LX200 254mm Schmidt-Cassegrain telescope with a 2x Barlow lens and a Lumenera SKYnyx 2-0M camera.

Jupiter and moons