Sunday, January 29, 2017

The Ambiguously Galactic Duo

M81 and M82 are two galaxies hanging out in the constellation Ursa Major, the Big Dipper. M81, on the right, is also referred to as Bode's Galaxy (for its discoverer, Johann Elert Bode). M82, on the left, is also know as the Cigar Galaxy.

Here are the wacky things about images like this one...

(1) Every single star you see in this image is in our own galaxy. It's easy to think you're seeing individual stars in M81 and M82 but that's simply not the case. At 12 million light years away, the galaxies are fairly close to us but they're still much too far to be able to resolve individual stars. Also, while there are such things as rogue stars that get flung out of their home galaxies due to gravitational disturbances, it would be quite rare for one to show up in an amateur astronomer's image.

(2) If your monitor is bright enough and calibrated well, you can see a lot of fuzzy patches, each of which is another galaxy!

Don't look at them too closely... M81 harbors a supermassive black hole. I wouldn't want anyone getting spaghettified.

Galaxies M81 (R) and M82 (L) in Ursa Major.
Takahashi TOA-150 telescope, FLI ML11002-C camera, 120 minutes of exposures (12 x 10 minutes)
CaliforniaStars Observatory, GMARS, Landers

Tuesday, August 9, 2016

Perseid Meteor Shower 2016 - Bang or Bust?

The Perseid meteor shower is coming up SOON! Here are some facts about how to view the shower.

  • What? Like all meteor showers, the Perseids occur annually. Also like all meteor showers, the Perseids are caused by the Earth making its way through the debris field of a comet that passed years prior. Those little specks of dust and rock (about 1 to 10mm in size) that the comet left behind smack into the Earth's atmosphere at about 35 miles per second and burn up in an instant, emitting a bright streak of light in the process. Different meteor showers are attributed to different comets. The comet in question for the Perseids is Comet Swift-Tuttle (109P/Swift-Tuttle), which made its way through the inner solar system most recently in 1992.
  • How? Get away from city lights! That's the most important bit of advice for viewing a meteor shower (other than open your eyes and look up). City lights create light pollution and wash out the fainter stars and meteors of the night sky. Go to the desert or the mountains at least 90 minutes from LA. Sit back in a comfortable reclining chair or lay on the ground with a blanket and/or air mattress. Aim yourself so you're looking northeast, but look up. Meteor showers are named for the constellation from which they appear to radiate. The Perseids are named for Perseus, which rises in the north east. But that doesn't mean you'll only see meteors in the vicinity of Perseus. They can appear anywhere in the sky, but they will always appear to radiate from Perseus, an effect of linear perspective. You don't need (or want) a telescope or binoculars to view a meteor shower, just your dark-adapted eyes.
  • When? Thursday night (8/11) into Friday morning (8/12). It'll actually be early Friday morning, about 1:00AM, by the time best viewing begins.

A Perseid meteor from the 2012 display shoots through the field of view in this image of the Heart Nebula.
100-minute exposure using a Takahashi FSQ-106EDX telescope and FLI ML11002-C camera.

  • What constitutes "best viewing"? Perseids appear to emanate from Perseus. Perseus rises relatively late in the evening this time of year and climbs higher throughout the early morning hours. The higher in the sky the radiant is, the clearer view we'll have of the meteors. Also, for the sky to be at its darkest, there must be no Moon. During this year's Perseid peak, the Moon sets at about 1:00AM (PDT) on Friday morning. When those two conditions are met (Perseus is high in the sky and the Moon has set), prime viewing will begin. This occurs between 1:00AM and dawn on Friday, 8/12. That's not to say you won't see any meteors on Thursday evening. You will. But you'll likely see more after midnight and after the Moon sets.
  • Will the sky be full of meteors? While the event is indeed called a "meteor shower," keep in mind that any source that claims there will be a "shower of meteors raining down" or something similar, is full of it. They probably also have photos of sharks attacking helicopters and warn of impending doom by a previously undiscovered sister star of the Sun. Except for very rare occasions, meteor showers typically consist of 1 or 2 streaks per minute, and that's considered a really good display! The Leonid meteor shower is known to have periodic "outbursts" — the 1966 and 1998 Leonids were considered meteor storms!
  • But I heard this year's Perseids are going to be crazy active. Is that true? This year's Perseids are predicted (by some) to be more active than most years — The theory is that Jupiter has perturbed the debris field left by Comet Swift-Tuttle, and placed a denser portion of it in Earth's orbital path. The problem is that no one knows for sure the density of the debris field, how squarely the Earth will hit it, what part of the Earth will hit it and when exactly, etc. The predictions rely on models that use a lot of assumed data. Remember Comet ISON? Yeah.

Get more information about the source of the Perseid meteors, Comet Swift-Tuttle. And find out more about meteor showers.

Enjoy the "shower!"

Sunday, June 5, 2016

Dusk in the Desert

Dusk in the desert can be a magical time. The sun has just set, temperatures continue to cool and pink and orange hues take over the landscape.

Star parties are a great way to experience that time of day. Here are a couple aerial shots as star party guests at GMARS gather and get ready for an evening of observing and imaging.

Star party-goers gather and set up at GMARS

Bird's eye view of GMARS along with the row of observatories and the telescope field
And, of course, here's an aerial video of the Landers area. It features the area at dusk, a 1-mile flight from GMARS to CS3 and back, flyovers of star party-goers, and a flight over Kate's Lazy Desert (at the end of the video).