by owlice » Sat Mar 12, 2011 5:45 pm
_____________________________________________________________________
Please vote for the
two best APODs (image and text) for February. All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOM, as this helps Jerry and Robert create "year in APOD images" review lectures and a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received.
We are very interested to know why you selected the APODs for which you voted; if you would like to tell us, please reply to this thread. Thank you!
Thank you!
_____________________________________________________________________
<- Previous month's poll
Sometimes a morning sky can be a combination of serene and surreal. Such a sky perhaps existed before sunrise this past Sunday as
viewed from a snowy slope in eastern
Switzerland. Quiet clouds blanket the above scene, lit from beneath by lights from the village of
Trübbach. A snow covered mountain,
Mittlerspitz, poses dramatically on the upper left, hovering over the small town of
Balzers,
Liechtenstein far below.
Peaks from the
Alps can be seen across the far right, just below the freshly
rising Sun. Visible on the upper right are the
crescent Moon and the bright planet
Venus. Venus will remain in the
morning sky all month, although it will likely not be found in such a photogenic setting.
Like a ship plowing through cosmic seas,
runaway star Zeta Ophiuchi produces the arcing interstellar bow wave or bow shock seen in this
stunning infrared portrait from the WISE spacecraft. In the false-color view, bluish Zeta Oph, a star about 20 times more massive than the Sun, lies near the center of the frame, moving toward the top at 24 kilometers per
second. Its strong stellar wind precedes it, compressing and heating the dusty
interstellar material and shaping the curved shock front. Around it are clouds of relatively undisturbed material. What set this star in motion? Zeta Oph was likely once a member of a
binary star system, its companion star was more massive and hence
shorter lived. When the companion
exploded as a supernova catastrophically losing mass, Zeta Oph was flung out of the system. About 460 light-years away, Zeta Oph is 65,000 times more luminous than the Sun and would be one of the brighter stars in the sky if it weren't surrounded by obscuring dust. The
WISE image spans about 1.5 degrees or 12 light-years at the estimated distance of
Zeta Ophiuchi.
Hanny's Voorwerp, Dutch for "Hanny's Object", is enormous,
about the size of our own Milky Way Galaxy. Glowing strongly in the greenish light produced by ionized oxygen atoms,
the mysterious voorwerp is below spiral galaxy IC 2497 in this
view from the Hubble Space Telescope. Both lie at a distance of some 650 million light-years in the faint constellation Leo Minor. In fact, the enormous green cloud is now suspected to be part of a
tidal tail of material
illuminated by a quasar inhabiting the center of IC 2497. Powered by a massive black hole, the quasar
suddenly turned off, leaving only galaxy and glowing voorwerp visible in telescopes at optical wavelengths. The sharp Hubble image also resolves a star forming region in the voorwerp, seen in yellow on the side near IC 2497. That region was likely compressed by an outflow of gas driven from the galaxy's core. The remarkable mystery object was discovered by Dutch schoolteacher
Hanny van Arkel in 2007 while participating online in the Galaxy Zoo project.
Galaxy Zoo enlists the public to help classify galaxies found in the Sloan Digital Sky Survey, and more recently in deep Hubble imagery.
A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of
Ursa Major. This sharp view of the gorgeous
island universe shows off a striking yellow nucleus and galactic disk. Dust lanes, small, pink star-forming regions, and young blue star clusters are embedded in the patchy, tightly
wound spiral arms.
In contrast, many other spirals exhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger than
our own Milky Way, but this
close-up Hubble image spans about 34,000 light-years along the the galaxy's inner region.
X-ray images suggest that resulting winds and stellar explosions create plumes of hot gas extending into a halo around NGC 2841.
What's visible in the night sky during this time of year? To help illustrate the answer, a beautiful land, cloud, and skyscape was captured earlier this month over
Neuchâtel,
Switzerland. Visible in the foreground were the snow covered cliffs of the amphitheater shaped
Creux du Van, as well as distant trees, and town-lit clouds. Visible in the night sky (at midnight) were galaxies including the
long arch of the central band of our
Milky Way Galaxy, the
Andromeda galaxy (M31), and the
Triangulum galaxy (
M33). Star clusters visible included NGC 752,
M34,
M35,
M41, the
double cluster, and the Beehive (
M44). Nebulas visible included the Orion Nebula (
M42),
NGC 7822,
IC 1396, the
Rosette Nebula, the
Flaming Star Nebula, the
California Nebula, the
Heart and
Soul Nebulas, and the
Pacman Nebula. Rolling your cursor over the
above image will bring up
labels for
all of these. But the above
wide angle sky image captured even more sky wonders. What other nebulas
can you find in the above image?
What's hovering between those buildings? The Moon. The above image was taken two weeks ago as the
full Snow Moon started to rise above
Edmonton,
Alberta,
Canada. The odd coincidence between the
angular size of the
far distant Moon and the angular width of nearby buildings created a striking juxtaposition. Backing away from the buildings so to reduce their angular size was a key to planning the image. The temperature was so low, -25
C, that plumes of steam rose from neighboring oil refineries. The above image was taken during a momentary break in the plumes. The
rising Moon appears red here for the same reason that a setting
Sun appears red -- because blue light is preferentially
scattered away by intervening air. In this case, the
shimmering steam plumes likely also caused the Moon to appear
slightly compressed. The next full moon, the
full Worm Moon, will occur in mid-March.
<- Previous month's poll
[size=200][color=#FF0000]_____________________________________________________________________[/color][/size]
Please vote for the [b]two[/b] best APODs (image and text) for February. All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOM, as this helps Jerry and Robert create "year in APOD images" review lectures and a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received.
We are very interested to know why you selected the APODs for which you voted; if you would like to tell us, please reply to this thread. Thank you!
Thank you!
[size=200][color=#FF0000]_____________________________________________________________________[/color][/size]
[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=22885&p=142917][color=#4040FF][b]<- Previous month's poll[/b][/color][/url][/size]
[c][url=http://apod.nasa.gov/apod/ap110202.html][size=150][b]Moon and Venus Over Switzerland (2010 Feb 2)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1102/moonvenus_kaplan_900.jpg[/img2][/float] Sometimes a morning sky can be a combination of serene and surreal. Such a sky perhaps existed before sunrise this past Sunday as [url=http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=47%C2%B004%2756.30%22+N+9%C2%B026%2753.21%22+E&sll=37.0625,-95.677068&sspn=36.642161,66.445312&ie=UTF8&ll=47.076727,9.438457&spn=0.030804,0.064888&t=h&z=14]viewed from[/url] a snowy slope in eastern [url=http://en.wikipedia.org/wiki/Switzerland]Switzerland[/url]. Quiet clouds blanket the above scene, lit from beneath by lights from the village of [url=http://en.wikipedia.org/wiki/Tr%C3%Bcbbach]Trübbach[/url]. A snow covered mountain, [url=http://en.wikipedia.org/wiki/Mittlerspitz]Mittlerspitz[/url], poses dramatically on the upper left, hovering over the small town of [url=http://en.wikipedia.org/wiki/Balzers]Balzers[/url], [url=http://en.wikipedia.org/wiki/Liechtenstein]Liechtenstein[/url] far below. [url=http://www.youtube.com/watch?v=pTR93Hf9gjI]Peaks[/url] from the [url=http://en.wikipedia.org/wiki/Alps]Alps[/url] can be seen across the far right, just below the freshly [url=http://apod.nasa.gov/apod/ap091223.html]rising Sun[/url]. Visible on the upper right are the [url=http://apod.nasa.gov/apod/ap070320.html]crescent Moon[/url] and the bright planet [url=http://apod.nasa.gov/apod/ap101020.html]Venus[/url]. Venus will remain in the [url=http://www.skyandtelescope.com/observing/ataglance/]morning sky[/url] all month, although it will likely not be found in such a photogenic setting.
[clear][/clear]
[c][url=http://apod.nasa.gov/apod/ap110204.html][size=150][b]Zeta Oph: Runaway Star (2010 Feb 4)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1102/zetaoph_wise_900c.jpg[/img2][/float]Like a ship plowing through cosmic seas, [url=http://apod.nasa.gov/apod/ap061124.html]runaway star[/url] Zeta Ophiuchi produces the arcing interstellar bow wave or bow shock seen in this [url=http://wise.ssl.berkeley.edu/gallery_zeta_ophiuchi.html]stunning infrared portrait[/url] from the WISE spacecraft. In the false-color view, bluish Zeta Oph, a star about 20 times more massive than the Sun, lies near the center of the frame, moving toward the top at 24 kilometers per [i]second[/i]. Its strong stellar wind precedes it, compressing and heating the dusty [url=http://espg.sr.unh.edu/ism/what1.html]interstellar material[/url] and shaping the curved shock front. Around it are clouds of relatively undisturbed material. What set this star in motion? Zeta Oph was likely once a member of a [url=http://apod.nasa.gov/apod/ap970219.html]binary star system[/url], its companion star was more massive and hence [url=http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/background-lifecycles.html]shorter lived[/url]. When the companion [url=http://en.wikipedia.org/wiki/Type_II_supernova]exploded as a supernova[/url] catastrophically losing mass, Zeta Oph was flung out of the system. About 460 light-years away, Zeta Oph is 65,000 times more luminous than the Sun and would be one of the brighter stars in the sky if it weren't surrounded by obscuring dust. The [url=http://wise.ssl.berkeley.edu/education_class.html]WISE[/url] image spans about 1.5 degrees or 12 light-years at the estimated distance of [url=http://stars.astro.illinois.edu/sow/zetaoph.html]Zeta Ophiuchi[/url].
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[c][url=http://apod.nasa.gov/apod/ap110210.html][size=150][b]Hanny's Voorwerp (2010 Feb 10)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1102/hannyVWRP_hst_900h.jpg[/img2][/float][url=http://apod.nasa.gov/apod/ap080625.html]Hanny's Voorwerp[/url], Dutch for "Hanny's Object", is enormous, [url=http://hubblesite.org/newscenter/archive/releases/2011/01/image/c/format/web/]about the size[/url] of our own Milky Way Galaxy. Glowing strongly in the greenish light produced by ionized oxygen atoms, [url=http://hannysvoorwerp.zooniverse.org/the-story-so-far/]the mysterious voorwerp[/url] is below spiral galaxy IC 2497 in this [url=http://hubblesite.org/newscenter/archive/releases/2011/01/]view from the Hubble Space Telescope[/url]. Both lie at a distance of some 650 million light-years in the faint constellation Leo Minor. In fact, the enormous green cloud is now suspected to be part of a [url=http://apod.nasa.gov/apod/ap100926.html]tidal tail[/url] of material [url=http://hubblesite.org/newscenter/archive/releases/2011/01/image/d/format/web_print/]illuminated by a quasar[/url] inhabiting the center of IC 2497. Powered by a massive black hole, the quasar [url=http://arxiv.org/abs/1011.0427]suddenly turned off[/url], leaving only galaxy and glowing voorwerp visible in telescopes at optical wavelengths. The sharp Hubble image also resolves a star forming region in the voorwerp, seen in yellow on the side near IC 2497. That region was likely compressed by an outflow of gas driven from the galaxy's core. The remarkable mystery object was discovered by Dutch schoolteacher [url=http://www.hannysvoorwerp.com/]Hanny van Arkel[/url] in 2007 while participating online in the Galaxy Zoo project. [url=http://www.galaxyzoo.org/story]Galaxy Zoo enlists[/url] the public to help classify galaxies found in the Sloan Digital Sky Survey, and more recently in deep Hubble imagery.
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[c][url=http://apod.nasa.gov/apod/ap110219.html][size=150][b]Spiral Galaxy NGC 2841 Close Up (2010 Feb 19)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1102/ngc2841c_hst_sm.jpg[/img2][/float]A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of [url=http://apod.nasa.gov/apod/ap070108.html]Ursa Major[/url]. This sharp view of the gorgeous [url=http://cass.ucsd.edu/public/tutorial/Galaxies.html]island universe[/url] shows off a striking yellow nucleus and galactic disk. Dust lanes, small, pink star-forming regions, and young blue star clusters are embedded in the patchy, tightly [url=http://casa.colorado.edu/~danforth/science/spiral/]wound[/url] [url=http://apod.nasa.gov/apod/ap030925.html]spiral[/url] arms. [url=http://apod.nasa.gov/apod/ap091017.html]In contrast[/url], many other spirals exhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger than [url=http://www.atlasoftheuniverse.com/galaxy.html]our own[/url] Milky Way, but this [url=http://hubblesite.org/newscenter/archive/releases/2011/06/]close-up Hubble image[/url] spans about 34,000 light-years along the the galaxy's inner region. [url=http://chandra.harvard.edu/photo/2006/n2841/]X-ray images[/url] suggest that resulting winds and stellar explosions create plumes of hot gas extending into a halo around NGC 2841.
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[c][url=http://apod.nasa.gov/apod/ap110221.html][size=150][b]Milky Way Over Switzerland (2010 Feb 21)[/b][/size][/url][/c]
[float=left][imghover=http://apod.nasa.gov/apod/image/1102/mwcliffs_vetter_900.jpg]http://apod.nasa.gov/apod/image/1102/mwcliffs_vetter_annotated_900.jpg[/imghover][/float]What's visible in the night sky during this time of year? To help illustrate the answer, a beautiful land, cloud, and skyscape was captured earlier this month over [url=http://en.wikipedia.org/wiki/Neuchatel]Neuchâtel[/url], [url=http://en.wikipedia.org/wiki/Switzerland]Switzerland[/url]. Visible in the foreground were the snow covered cliffs of the amphitheater shaped [url=http://en.wikipedia.org/wiki/Creux_du_Van]Creux du Van[/url], as well as distant trees, and town-lit clouds. Visible in the night sky (at midnight) were galaxies including the [url=http://apod.nasa.gov/apod/ap080713.html]long arch[/url] of the central band of our [url=http://asterisk.apod.com/viewtopic.php?f=24&t=18006]Milky Way Galaxy[/url], the [url=http://apod.nasa.gov/apod/ap090510.html]Andromeda galaxy[/url] (M31), and the [url=http://www.youtube.com/watch?v=p5QPRez-hyU]Triangulum[/url] galaxy ([url=http://apod.nasa.gov/apod/ap101203.html]M33[/url]). Star clusters visible included NGC 752, [url=http://apod.nasa.gov/apod/ap100211.html]M34[/url], [url=http://apod.nasa.gov/apod/ap031215.html]M35[/url], [url=http://en.wikipedia.org/wiki/Messier_41]M41[/url], the [url=http://apod.nasa.gov/apod/ap091204.html]double cluster[/url], and the Beehive ([url=http://apod.nasa.gov/apod/ap040617.html]M44[/url]). Nebulas visible included the Orion Nebula ([url=http://apod.nasa.gov/apod/ap090222.html]M42[/url]), [url=http://apod.nasa.gov/apod/ap101022.html]NGC 7822[/url], [url=http://apod.nasa.gov/apod/ap090819.html]IC 1396[/url], the [url=http://apod.nasa.gov/apod/ap070214.html]Rosette Nebula[/url], the [url=http://apod.nasa.gov/apod/ap090126.html]Flaming Star Nebula[/url], the [url=http://apod.nasa.gov/apod/ap060924.html]California Nebula[/url], the [url=http://apod.nasa.gov/apod/ap090214.html]Heart[/url] and [url=http://apod.nasa.gov/apod/ap080914.html]Soul Nebulas[/url], and the [url=http://apod.nasa.gov/apod/ap050823.html]Pacman Nebula[/url]. Rolling your cursor over the [url=http://www.nuitsacrees.fr/DP/CV_apod2000.jpg]above image[/url] will bring up [url=http://www.mcckc.edu/longview/socsci/psyc/westra/Adol/DDUMKC/Archetypes/inigo-montoya-HelloMyNameIs.jpg]labels[/url] for [url=http://www.nuitsacrees.fr/DP/CV_apod2000_comments.jpg]all of these[/url]. But the above [url=http://www.sergebrunier.com/gallerie/pleinciel/360.swf]wide angle sky image[/url] captured even more sky wonders. What other nebulas [url=http://asterisk.apod.com/discuss_apod.php?date=110221]can you find[/url] in the above image?
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[c][url=http://apod.nasa.gov/apod/ap110228.html][size=150][b]Red Snow Moon Over Edmonton (2010 Feb 28)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1102/mooncity_vanzella_900.jpg[/img2][/float]What's hovering between those buildings? The Moon. The above image was taken two weeks ago as the [url=http://www.farmersalmanac.com/astronomy/2009/02/09/full-snow-moon/]full Snow Moon[/url] started to rise above [url=http://en.wikipedia.org/wiki/Edmonton]Edmonton[/url], [url=http://en.wikipedia.org/wiki/Alberta]Alberta[/url], [url=http://en.wikipedia.org/wiki/Canada]Canada[/url]. The odd coincidence between the [url=http://www.1728.com/angsize.htm]angular size[/url] of the [url=http://apod.nasa.gov/apod/ap071025.html]far distant Moon[/url] and the angular width of nearby buildings created a striking juxtaposition. Backing away from the buildings so to reduce their angular size was a key to planning the image. The temperature was so low, -25 [url=http://www.sizes.com/units/temperature_centigrade.htm]C[/url], that plumes of steam rose from neighboring oil refineries. The above image was taken during a momentary break in the plumes. The [url=http://www.youtube.com/watch?v=-ifTCa97G6Q]rising Moon[/url] appears red here for the same reason that a setting [url=http://apod.nasa.gov/apod/ap980526.html]Sun appears red[/url] -- because blue light is preferentially [url=http://www.weeklydavespeak.com/wdextra/audio/Davespeak/Messy%20Hair/Cat%20Hair.jpg]scattered[/url] away by intervening air. In this case, the [url=http://apod.nasa.gov/apod/ap101019.html]shimmering[/url] steam plumes likely also caused the Moon to appear [url=http://apod.nasa.gov/apod/ap090223.html]slightly compressed[/url]. The next full moon, the [url=http://www.farmersalmanac.com/full-moon-names/]full Worm Moon[/url], will occur in mid-March.
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[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=22885&p=142917][color=#4040FF][b]<- Previous month's poll[/b][/color][/url][/size]