December 18, 2017

03.06.10: Do “Dirty” White Dwarfs Provide a Key Spectral Signature?

 

If astronomers at the Leicester University in the United Kingdom are correct, the key elements and chemicals that comprise life may be common throughout our Milky Way. The evidence comes from an unlikely source; spectral examinations of populations of galactic white dwarfs. These ancient remnants of stars exist in vast numbers, and our Sun will indeed share their fate one day. The study, led by researcher Jay Farihi, looked at over 100 million objects in the Sloan Digital Sky Survey, which provides a map of the sky and our galaxy as seen in the infrared spectrum. Their findings conclude that up to 20% of all white dwarfs surveyed are contaminated with trace metals, most likely the result of interplanetary debris. In the field of astronomy, the term “metal” refers to anything that isn’t hydrogen or helium, a little different definition than what you learned (hopefully) in high school chemistry. The thinking goes that where heavier elements are seen, terrestrial planets and perhaps life may be sure to follow. Our Sun itself is a good case in point; a Population I star that is relatively metal rich, allowing for a large retinue of rocky planets, including the Earth. How common or rare we are is still hotly debated, but this analysis of the atmospheres of white dwarfs may prove that terrestrial worlds are perhaps abundant throughout the cosmos.  In terms of this study, astronomers are in a sense looking at the “ruins” of older terrestrial systems that will be recycled and incorporated into new, metal dense populations… perhaps one could argue that as time in universe marches on and heavier elements become more abundant, the odds are that life will become more frequent, at least until the stelliferous era runs its course!

01.06.10: Do Primordial Magnetic Fields Roam the Cosmos?

NASA’s Fermi Gamma-ray Space Telescope may have uncovered a new high energy mystery. Like our own Earth, galaxies and even large scale galaxy clusters have magnetic fields shrouding them. The fields of mature galaxies such as our own Milky Way should have been seeded during the early formation of their weaker ancient counterparts. Perhaps these got their start from early supernovae, which spewed charged particles forth into the cosmos. These galactic magnetic fields may even help control the modern era rates of star formation, as well as regulate interstellar gas and guide cosmic rays.

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Astro-Challenge:The Magellanic Clouds.

Ah…the southern hemisphere has all the good stuff. As we here at Astroguyz dip below the equator for the fifth time on a trip to Ecuador, we thought we’d include an old friend and a unique celestial pairing that most people have never seen. The Magellanic clouds are actually small satellite galaxies of our own Milky Way; the Large Magellanic cloud (LMC) is at a distance of 160,000 light years and contains about 10 billion stars, while the Small Magellanic cloud (SMC) is at a distance of 200,000 light years and weighs in at 7 billion solar masses.

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05.10.09 The 3rd Annual Great World Wide Star Count!

Tired of the deteriorating sky conditions in your neighborhood? Remember a childhood when the Milky way was visible in your backyard, such as it was in our native rural northern Maine? Now there is something that you can do about it. The Great World Wide Star Count wants you to measure the limiting magnitude from your locale in an effort to document light pollution. Its simple; if you can locate the constellation Cygnus in the northern hemisphere and Sagittarius in the southern, then you can participate. No equipment is required, just your eyes, and a tutorial is included on the site. This is the third year around for the Star Count, and we’ve participated here at Astroguyz for the last two years running. It’s great fun to see the reports from various areas, as well as were the astronomers are! This year, the dates run from October 9th to the 23rd, and you can enter reports from multiple sites…put your town on the map! Post Anti-Light Pollution slogans! Show the neighbor the damage that vintage “Battle of Britain” anti-aircraft spotlight is causing! We prefer to document our impressions of the sky for later entry via digital voice recorder, but you’ll no doubt settle on your own system. Now is the time to try a “dry-run” a night or two before the Count starts Friday…anyone thought of posting observations via Twitter? What would be really great is to get reports from such off-the-wall locales such as Thule, Greenland or Poipet, Cambodia…do your part to raise light pollution awareness in your neighborhood!

August 2009:News & Notes

- The LRO Photographs the Apollo landing sites: Fans of this space may have noticed the racy lunar pics we ran a week back as part of our From Earth to the Moon review. The Lunar Reconnaissance Orbiter did indeed snap pics of the famous Apollo landing sites last month. These clearly show the hardware left at multiple sites, as well as the base(s) of the Lunar Lander ascent stages, complete with shadow. You can even see the astronaut’s foot trails in the lunar dust! And the LRO hasn’t even entered its cruising orbit yet… expect more great pics to come! [Read more...]