Posts tagged 'Geminids'

Observing Report 13th-14th and 14th-15th December 2012 (Geminids Part 1)

Posted by on December 15th 2012 in Astrostuff, Observing Reports
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The best period for seeing the Geminids was from dusk on Thursday to dawn on Friday. I was ready early with the D50 set up on the mount, toting the 35mm prime, and intending to track a bit of sky around Taurus. The evening started cloudy but I was convinced that there would be some clear spells before sun-up. Suffice to say that there wasn't a single cloud-gap all night and I gave in to sleep at around 4 a.m. when the mist came down and then froze. It had been a wasted night, and the fact that folk in other places had been seeing the best Geminid display for many a year was really rubbing it in.

The forecast for the next night was slightly better, the cloud was supposed clear sometime around midnight, so I decided to have another go even though the meteor-rate would be much lower. Same kit, this time tracking a vague area between Lynx and Ursa Major. The clouds did part and there was still a fair number of Geminids whizzing about, I took 300 pics and managed to catch just the one meteor trail. It was a promising start.

I re-aimed the camera and rattled off another 35 shots in the direction of Camelopardalis before the constellation became obstructed by the observatory roof. By this time Leo had risen so far that it was fully in the field of view so I aimed at that and ran off another 300 shots before it clouded over fully, ending the session.

After a short sleep and a wonderful afternoon of festive shopping I got around to processing the images, here's the best of the Geminids that I caught on camera:

 Geminid meteor in Ursa Major
Main image: 19 x 30s subs @ ISO 400, stacked with DSS
Luminance layer: 1 x 30s sub processed in PS CS3
Final layering in PS CS3

Here's a screenshot from Starry Night Pro Plus 6, showing roughly where the FOV was:

 

 The FOV of the 35mm prime on the D50
The red triangle marks the radiant point of the Geminid meteor shower
Compare the two images and you'll see that those naughty twins appear to have shot the Great Bear up the arse

Observing Report 10th-11th December 2009 (Frosty Mars)

Posted by on December 13th 2009 in Astrostuff, My vids, Observing Reports
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The weather here on Thursday evening was a bit odd - periods of thick fog alternating with cold clear spells. I got the scope set up early and while waiting for the longer clear bits I used the odd short bits of good visibility to get good focus and tracking. Oh, and to fight the battle against condensation on the kit.

Some time after midnight the fog lifted and everything was clear and still, not a breath of wind and the seeing was brilliant. All of the condensation froze within minutes. Undeterred by the layer of ice on the kit, I had a good look at Mars before nabbing some webcam footage of it. Visually, I'd never seen it so good - the polar cap was really bright and the planet was almost motionless, unlike the previous Mars session when the thing was moving around like a demented Morris Dancer. I spent a good hour or so just studying the surface detail, something I've never been able to do before. Here's some of that webcam footage after selecting a 256x256px region of interest around the planet:

Soon it was time to move on. I changed the eyepiece setup and this caused some melting of the ice on the kit. Figuring that it would be best to let the temperature settle down a bit I nipped in for a cuppa and then sat outside for twenty minutes watching a fair few meteors blazing across from East to West - they were mostly Geminids but there were a few others up there. I did contemplate setting up the D50 with the 35mm prime in order to get some images, but the camera was by now well-frozen and I wasn't going to risk trashing the mechanics inside the lens.

When all was settled I slewed the scope around to Saturn, which had risen to a reasonable height above the horizon. It looked a bit dimmer than I've seen it before but I could still see the rings, not far past being edge-on. A couple of dim moons were visible but not much else. I grabbed a fair few avis with the webcam but they didn't look much good.

After another half-hour of visual, watching Saturn and some more meteors, the fog returned. This time it was thick, freezing, and obviously here to stay. I ended the session and closed the obsy roof. The next hour was spent mopping up meltwater from the kit and from the underside of the roof. I returned to the house at 06:00 vowing to get a cheap dehumidifier in the post-Christmas sales.

Anyway, I did some preliminary processing of the Mars data and sent the pics to a learned friend. He's confident that he's identified the surface features correctly, and pointed out the tiny clouds in the vicinity of Olympus Mons. He also reckons that the colours are fine, but I'm not so sure:

 

 

Again, you'll have to wait for me to find time to process the Saturn data.

I'll finish with a reminder - don't forget that Geminid meteor shower.

Clear skies tomorrow night

Posted by on December 12th 2007 in Astrostuff, Weather

Well, that's the weather forecast for here. Couple that with an ideal phase of the moon, and we have good conditions for standing outside, freezing our nuts off, looking for Geminid meteors. Let's hope that the weather holds for this shower... last month it was looking good for observing the Leonid shower until a front moved in and gave us 48 hours of 8/8 cloud-cover and heavy rain.

Here's an extract from the IMO Meteor Shower Calendar 2007:

One of the finest, and probably the most reliable, of the major annual showers presently observable. This year, the waxing crescent Moon will set by mid-evening across the globe on December 14 (the actual moonset timing is progressively later the further south you are), giving mostly dark skies for all observers, especially those in the northern hemisphere. The Geminid radiant culminates around 2h local time, but well north of the equator it rises around sunset, and is at a usable elevation from the local evening hours onwards, while in the southern hemisphere, the radiant appears only around local midnight or so. Even from more southerly sites, this is a splendid stream of often bright, medium-speed meteors, a rewarding sight for all watchers, whatever method they employ.

Here's some good advice from NASA for those hardy souls who intend to venture forth to see the lightshow:

  • Geminids meteors can be seen anytime after 10 p.m. local time, when the constellation Gemini is well above the horizon, but the best time to look is during the early morning hours between about 2 a.m. and dawn. That's when the local sky is pointing directly into the Geminid meteor stream.
  • The radiant of the Geminid shower is located near Castor, one of the two bright stars in Gemini (the other bright star is Pollux). To find the constellation at 2:00 a.m., go outside and face south. Castor and Pollux will appear approximately 45 degrees* above the horizon. Earlier in the evening, from 10:00 p.m. until midnight, Gemini will be about 30 degrees* above the horizon in the southeast.
  • You won't need binoculars or a telescope, the naked eye is usually best for seeing meteors which often streak more than 45 degrees across the sky. The field of view of most binoculars and telescopes is simply too narrow for good meteor observations.
  • Experienced meteor observers suggest the following viewing strategy: Dress warmly, as the mid-December nights are likely to be cold in the Northern hemisphere. Bring a reclining chair, or spread a thick blanket over a flat spot of ground. Lie down and look up somewhat toward the south. Meteors can appear in any part of the sky, although their trails will tend to point back toward the radiant.

(* this depends on your latitude)

Theoretically, the peak rate (ZHR) is predicted to be 120 meteors per hour, so it should be a good show.

Hopefully I'll be allowed out to catch some of the display on camera.

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