by owlice » Thu Jan 20, 2011 6:42 am
________________________________________________________________
Please vote for the TWO best Astronomy Pictures of the Day (image and text) of January 9-15
(Repeated APODs are not included in the poll.)
All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOW, as this helps Jerry and Robert create "year in APOD images" review lectures, creates APOM polls that can be used to create a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received. You can select two top images for the week.
Thank you!
________________________________________________________________
<- Previous week's poll
What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a large
lens. In the above case, however, there are actually millions of lenses:
ice crystals. As water freezes in the upper
atmosphere, small, flat, six-sided, ice crystals might be formed. As these
crystals flutter to the ground, much time is spent with their faces flat, parallel to the ground. An
observer may pass through the same plane as many of the falling ice crystals near sunrise or sunset. During this alignment, each crystal can act like a miniature lens, refracting sunlight into our
view and creating
phenomena like parhelia, the technical term for
sundogs. The above image was taken last year in
Stockholm,
Sweden. Visible in the image center is the Sun, while two bright
sundogs glow prominently from both the left and the right.
Also visible is the bright
22 degree halo -- as well as the rarer and much fainter
46 degree halo -- also created by
sunlight reflecting off of atmospheric ice
crystals.
It is the largest and most complex star forming region in the entire galactic neighborhood. Located in the
Large Magellanic Cloud, a small satellite galaxy orbiting our Milky Way galaxy,
the region's spidery appearance is responsible for its popular name, the
Tarantula nebula. This tarantula, however, is about 1,000
light-years across. Were it placed at the distance of Milky Way's
Orion Nebula, only 1,500 light-years distant and the nearest stellar nursery to Earth, it would appear to cover about 30 degrees (60
full moons) on the sky. Intriguing details of the nebula are visible in
the above image shown in
scientific colors. The spindly arms of the
Tarantula nebula surround
NGC 2070, a
star cluster that contains some of the brightest, most
massive stars known, visible in blue on the right. Since massive stars
live fast and die young, it is not so surprising that the
cosmic Tarantula also lies near the site of the closest
recent supernova.
This broad expanse of glowing gas and dust presents a bird-like visage to astronomers
from planet Earth, suggesting its popular moniker -
The Seagull Nebula.
This portrait of the cosmic bird covers a 1.6 degree wide swath across the plane of the Milky Way,
near the direction of Sirius, alpha star of the constellation Canis Major. Of course, the region includes objects with other
catalog designations: notably
NGC 2327, a compact, dusty emission region with an embedded massive star that forms the bird's head (aka the Parrot Nebula, above center).
IC 2177 forms the sweeping arc of the seagull's wings. Dominated by the
reddish glow of atomic hydrogen, the complex of gas and dust clouds with bright young stars spans over 100 light-years at an estimated 3,800 light-year distance.
Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years distant, toward the
constellation Leo. Spanning some 50,000 light-years, its central region is shown in
this dramatic image, constructed from data drawn from the
Hubble Legacy Archive. The close-up view highlights this galaxy's
characteristic multiple, patchy, irregular spiral arms laced with dust and clusters of young, blue stars.
In constrast, many other spirals exhibit grand, sweeping arms. A relatively bright galaxy in planet Earth's sky,
NGC 3521 is easily visible in small telescopes, but often overlooked by amateur imagers in favor of other Leo spiral galaxies, like
M66 and M65.
The
Quadrantid Meteor Shower is an annual event for planet Earth's northern hemisphere skygazers. It usually peaks briefly in the cold, early morning hours of January 4. The shower is named for its
radiant point on the sky within the old, astronomically obsolete constellation
Quadrans Muralis. That position is situated near the boundaries of the modern constellations Hercules, Bootes, and Draco. In
this haunting time exposure, two quadrantid meteor streaks are captured
crossing trails left by rising stars of the constellations Virgo and Corvus, but Saturn leaves the brightest "star" trail. The meteor streaks, one bright and one faint, are nearly parallel above and right of center in the frame. Fittingly, the old cistern structure in the foreground lies above the now
buried city of Qumis. Known as a city of many gates, Qumis (in Greek history
Hecatompylos), was founded 2300 years ago in ancient Persia.
<- Previous week's poll
[size=200][color=#FF0000]________________________________________________________________[/color][/size]
Please vote for the TWO best Astronomy Pictures of the Day (image and text) of January 9-15
(Repeated APODs are not included in the poll.)
All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOW, as this helps Jerry and Robert create "year in APOD images" review lectures, creates APOM polls that can be used to create a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received. You can select two top images for the week.
Thank you!
[size=200][color=#FF0000]________________________________________________________________[/color][/size]
[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=22664][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]
[c][url=http://apod.nasa.gov/apod/ap110110.html][size=150][b]A Sun Halo Beyond Stockholm (2011 Jan 10)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/sunhalo_rosen.jpg[/img2][/float] What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a large [url=http://www.opticalres.com/optics_for_kids/kidoptx_p2.html]lens[/url]. In the above case, however, there are actually millions of lenses: [url=http://www.its.caltech.edu/~atomic/snowcrystals/halos/halos.htm]ice crystals[/url]. As water freezes in the upper [url=http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html]atmosphere[/url], small, flat, six-sided, ice crystals might be formed. As these [url=http://en.wikipedia.org/wiki/Ice_crystal]crystals[/url] flutter to the ground, much time is spent with their faces flat, parallel to the ground. An [url=http://www.youtube.com/watch?v=RLYg5jptvCc]observe[/url]r may pass through the same plane as many of the falling ice crystals near sunrise or sunset. During this alignment, each crystal can act like a miniature lens, refracting sunlight into our [url=http://apod.nasa.gov/apod/ap100208.html]view[/url] and creating [url=http://www.atoptics.co.uk/halo/parhelia.htm]phenomena like parhelia[/url], the technical term for [url=http://apod.nasa.gov/apod/ap990823.html]sundogs[/url]. The above image was taken last year in [url=http://en.wikipedia.org/wiki/Stockholm]Stockholm[/url], [url=http://en.wikipedia.org/wiki/Sweden]Sweden[/url]. Visible in the image center is the Sun, while two bright [url=http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/opt/ice/sd.rxml]sundogs[/url] glow prominently from both the left and the right. [url=http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/halo.html]Also visible[/url] is the bright [url=http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/halo22.html]22 degree halo[/url] -- as well as the rarer and much fainter [url=http://www.atoptics.co.uk/halo/46hal.htm]46 degree halo[/url] -- also created by [url=http://www.atoptics.co.uk/halo/circular.htm]sunlight reflecting[/url] off of atmospheric ice [url=http://apod.nasa.gov/apod/ap080618.html]crystals[/url].
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[c][url=http://apod.nasa.gov/apod/ap110111.html][size=150][b]The Cosmic Web of the Tarantula Nebula (2011 Jan 11)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/tarantula_salemme.jpg[/img2][/float] It is the largest and most complex star forming region in the entire galactic neighborhood. Located in the [url=http://apod.nasa.gov/apod/ap081219.html]Large Magellanic Cloud[/url], a small satellite galaxy orbiting our Milky Way galaxy, [url=http://www.youtube.com/watch?v=DOZUR67efjw]the region[/url]'s spidery appearance is responsible for its popular name, the [url=http://coolcosmos.ipac.caltech.edu/cosmic_classroom/multiwavelength_astronomy/multiwavelength_museum/30dor.html]Tarantula nebula[/url]. This tarantula, however, is about 1,000 [url=http://chandra.harvard.edu/photo/cosmic_distance.html]light-years[/url] across. Were it placed at the distance of Milky Way's [url=http://apod.nasa.gov/apod/ap050918.html]Orion Nebula[/url], only 1,500 light-years distant and the nearest stellar nursery to Earth, it would appear to cover about 30 degrees (60 [url=http://apod.nasa.gov/apod/ap051113.html]full moons[/url]) on the sky. Intriguing details of the nebula are visible in [url=http://www.astromgs.com.ar/fotos/ngc2070_Ha_SII_OIII_112010.html]the above image[/url] shown in [url=http://hubblesource.stsci.edu/services/articles/2005-02-10/]scientific colors[/url]. The spindly arms of the [url=http://en.wikipedia.org/wiki/Tarantula]Tarantula[/url] nebula surround [url=http://adsabs.harvard.edu/abs/1995AstL...21..663S]NGC 2070[/url], a [url=http://asterisk.apod.com/viewtopic.php?f=24&t=18009]star cluster[/url] that contains some of the brightest, most [url=http://apod.nasa.gov/apod/ap070506.html]massive stars[/url] known, visible in blue on the right. Since massive stars [url=http://rebel-without-a-cause.blogspot.com/]live fast and die young[/url], it is not so surprising that the [url=http://apod.nasa.gov/apod/ap051212.html]cosmic Tarantula[/url] also lies near the site of the closest [url=http://apod.nasa.gov/apod/ap951027.html]recent supernova[/url].
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[c][url=http://apod.nasa.gov/apod/ap110112.html][size=150][b]The Seagull Nebula (2011 Jan 12)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/SeaGullLHaRGB_sidonio800.jpg[/img2][/float]This broad expanse of glowing gas and dust presents a bird-like visage to astronomers [url=http://apod.nasa.gov/apod/ap090411.html]from planet Earth[/url], suggesting its popular moniker - [url=http://www.celestialwonders.com/nebulae/Gum_20090227.html]The Seagull Nebula[/url]. [url=http://www.pbase.com/strongmanmike2002/the_sea_gull_nebula]This portrait[/url] of the cosmic bird covers a 1.6 degree wide swath across the plane of the Milky Way, [url=http://www.eanet.com/kodama/astro/2007/0216a/index.htm]near the direction[/url] of Sirius, alpha star of the constellation Canis Major. Of course, the region includes objects with other [url=http://galaxymap.org/cgi-bin/gum.py?s=1]catalog designations[/url]: notably [url=http://www.skyfactory.org/ic2177/ic2177.htm]NGC 2327[/url], a compact, dusty emission region with an embedded massive star that forms the bird's head (aka the Parrot Nebula, above center). [url=http://www.astropix.com/HTML/B_WINTER/IC2177.HTM]IC 2177[/url] forms the sweeping arc of the seagull's wings. Dominated by the [url=http://apod.nasa.gov/apod/ap080424.html]reddish glow[/url] of atomic hydrogen, the complex of gas and dust clouds with bright young stars spans over 100 light-years at an estimated 3,800 light-year distance.
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[c][url=http://apod.nasa.gov/apod/ap110113.html][size=150][b]NGC 3521 Close Up (2011 Jan 13)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/NGC3521_hstGendler900c.jpg[/img2][/float] Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years distant, toward the [url=http://www.universetoday.com/21173/leo/]constellation Leo[/url]. Spanning some 50,000 light-years, its central region is shown in [url=http://www.robgendlerastropics.com/NGC3521-HST-Gendler.html]this dramatic image[/url], constructed from data drawn from the [url=http://hla.stsci.edu/]Hubble Legacy Archive[/url]. The close-up view highlights this galaxy's [url=http://adsabs.harvard.edu/abs/1982MNRAS.201.1021E]characteristic[/url] multiple, patchy, irregular spiral arms laced with dust and clusters of young, blue stars. [url=http://apod.nasa.gov/apod/ap101209.html]In constrast[/url], many other spirals exhibit grand, sweeping arms. A relatively bright galaxy in planet Earth's sky, [url=http://www.astrosurf.com/antilhue/ngc3521.htm]NGC 3521 is[/url] easily visible in small telescopes, but often overlooked by amateur imagers in favor of other Leo spiral galaxies, like [url=http://apod.nasa.gov/apod/ap060309.html]M66 and M65[/url].
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[c][url=http://apod.nasa.gov/apod/ap1101014.html][size=150][b]Quadrantids over Qumis (2011 Jan 14)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/quadqumis_tafreshi900.jpg[/img2][/float]The [url=http://spaceweather.com/meteors/quadrantids/quadrantids.html]Quadrantid Meteor Shower[/url] is an annual event for planet Earth's northern hemisphere skygazers. It usually peaks briefly in the cold, early morning hours of January 4. The shower is named for its [url=http://apod.nasa.gov/apod/ap070812.html]radiant point[/url] on the sky within the old, astronomically obsolete constellation [url=http://www.ianridpath.com/startales/quadrans.htm]Quadrans Muralis[/url]. That position is situated near the boundaries of the modern constellations Hercules, Bootes, and Draco. In [url=http://www.twanight.org/newTWAN/photos.asp?ID=3003009&Sort=Photographer]this haunting time exposure[/url], two quadrantid meteor streaks are captured [url=http://apod.nasa.gov/apod/ap101224.html]crossing trails[/url] left by rising stars of the constellations Virgo and Corvus, but Saturn leaves the brightest "star" trail. The meteor streaks, one bright and one faint, are nearly parallel above and right of center in the frame. Fittingly, the old cistern structure in the foreground lies above the now [url=http://www.livius.org/he-hg/hecatompylos/hecatompylos.html]buried city of Qumis[/url]. Known as a city of many gates, Qumis (in Greek history [url=http://en.wikipedia.org/wiki/Hecatompylos]Hecatompylos[/url]), was founded 2300 years ago in ancient Persia.
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[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=22664][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]