by owlice » Mon Oct 17, 2011 2:39 am
_______________________________________________________________
Please vote for the TWO best Astronomy Pictures of the Day (image and text) of October 9-15, 2011.
(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, create APOM and
APOY 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.
We are very interested in why you selected the APODs you voted for, and enthusiastically welcome your telling us why by responding to this thread.
Thank you!
_______________________________________________________________
<- Previous week's poll
Thirteen years ago
results were
first presented indicating that most of the energy in our universe is not in stars or galaxies but is tied to space itself. In the language of cosmologists, a large
cosmological constant is directly implied by new distant
supernova observations. Suggestions of a
cosmological constant (lambda) were
not new -- they have existed since the advent of
modern relativistic cosmology. Such claims were not usually popular with astronomers, though, because lambda is so unlike known
universe components, because lambda's value appeared limited by other observations, and because less-
strange cosmologies without lambda had previously done well in explaining the data. What is noteworthy here is the seemingly direct and reliable method of the observations and the good reputations of the
scientists conducting the investigations. Over the
past thirteen years, independent teams of astronomers have continued to accumulate data that appears to
confirm the existence of
dark energy and the unsettling result of a presently
accelerating universe. This year, the team leaders were
awarded the Nobel Prize in Physics for their work. The
above picture of a supernova that occurred in
1994 on the outskirts of a
spiral galaxy was taken by one of these collaborations.
Why would a rising Sun look so strange? No one is yet sure. What is clear is that the above unusual sunrise was captured last month from
Buenos Aires,
Argentina. The body of water in the foreground is
Rio de La Plata, considered by many to be the widest river in the world. Although the
above image is actually a combination of a normal and a very short exposure needed to avoid
oversaturating the bright Sun, the photographer saw this unusual structure with his own eyes, indicating that this effect was caused by neither
reflections nor
distortions in the camera or lens. What looks like arms on this
monster illusion might actually be, for example, low level clouds just thick enough to scatter sunlight without completely
blocking the Sun. Additionally, the distortion visible on the lower part of the Sun's image might indicate a
Etruscan Vase or
Fata Morgana mirage possibly created by a curious
refracting layer of air over the water. Unusual
atmospheric phenomena are frequently
thrilling to see personally, and although most can be
traced to well known phenomena, others, for lack of more data,
remain mysterious.
It's the bubble versus the cloud. NGC 7635, the
Bubble Nebula, is being pushed out by the
stellar wind of massive central star
BD+602522. Next door, though, lives a giant
molecular cloud, visible to the right. At this place in space, an
irresistible force meets an
immovable object in an interesting way. The
cloud is able to contain the expansion of the bubble gas, but gets blasted by the hot radiation from the
bubble's central star. The
radiation heats up dense regions of the
molecular cloud causing it to glow. The
Bubble Nebula,
pictured above in scientifically mapped colors to bring up contrast, is about 10
light-years across and part of a much
larger complex of stars and shells. The
Bubble Nebula can be seen with a small telescope towards the
constellation of the Queen of
Aethiopia (
Cassiopeia).
Saturn's rings form one of the larger sundials known. This
sundial, however, determines only the
season of Saturn, not the time of day. In 2009, during
Saturn's last equinox, Saturn's thin rings threw
almost no shadows onto Saturn, since the ring plane pointed directly toward the Sun. As Saturn continued in its orbit around the Sun, however, the ring shadows become increasingly wider and cast further south. These shadows are not easily visible from the Earth because from our vantage point near the Sun, the rings
always block the shadows. The
above image was taken in August by the
robotic Cassini spacecraft currently orbiting Saturn. The rings themselves appear as a vertical bar on the image right. The Sun, far to the upper right, shines through the rings and casts captivatingly
complex shadows on south Saturn, on the image left. Cassini has been
exploring Saturn, its rings, and its moons since 2004, and is
expected to continue until at least the maximum elongation of Saturn's shadows occurs in 2017.
This sharp cosmic portrait features
glowing gas and obscuring dust clouds in IC 1795, a star forming region in the northern constellation
Cassiopeia. Also cataloged as NGC 896, the nebula's remarkable details, shown in its dominant red color, were captured using a sensitive camera, and long exposures that include image data from a narrowband filter. The narrow filter transmits only
H-alpha light, the red light of hydrogen atoms. Ionized by ultraviolet light from energetic young stars, a hydrogen atom emits the characteristic H-alpha light as its single electron is recaptured and transitions to lower energy states. Not far on the sky from the famous
Double Star Cluster in Perseus, IC 1795 is itself located next to IC 1805, the
Heart Nebula, as part of a
complex of star forming regions that lie at the edge of a large molecular cloud. Located just over 6,000 light-years away, the larger star forming complex sprawls along the Perseus spiral arm of our
Milky Way Galaxy. At that distance, this picture would span about 70 light-years across IC 1795.
Colorful
star trails arc across the night in this surreal
timelapse skyscape from the
Roque de los Muchachos Observatory on the Canary island of La Palma.
A reflection of the Earth's daily rotation on its axis, the star trails are also reflected in one of a pair of 17 meter diameter, multi-mirrored
MAGIC telescopes. The MAGIC (Major Atmospheric Gamma Imaging Cherenkov)
telescope itself is intended to detect gamma rays - photons with over 100 billion times the energy of visible light. As the high energy gamma rays impact the upper atmosphere they produce
air showers of high-energy particles. A fast camera monitoring the multi-mirrored surface records
in detail brief flashes of optical light, called
Cherenkov light, created by the air shower particles Astronomers can then ultimately relate the optical flashes to
cosmic sources of extreme gamma-rays.
Magnificent spiral galaxy
NGC 4565 is viewed edge-on from planet Earth. Also known as the
Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation
Coma Berenices.
This sharp, colorful image reveals the galaxy's bulging central core cut by obscuring
dust lanes that lace NGC 4565's
thin galactic plane. An assortment of other background galaxies is included in the pretty field of view, with neighboring galaxy NGC 4562 at the lower right. NGC 4565 itself lies about 40 million
light-years distant and spans some 100,000 light-years. Easily spotted with small telescopes,
sky enthusiasts consider
NGC 4565 to be a prominent celestial masterpiece
Messier missed.
<- 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 October 9-15, 2011.
(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 "[url=http://www.youtube.com/watch?v=NAQXYYbBa1s]year in APOD images[/url]" review lectures, create APOM and [url=http://asterisk.apod.com/viewtopic.php?f=29&t=22695&p=141942#p141942]APOY polls[/url] 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.
We are very interested in why you selected the APODs you voted for, and enthusiastically welcome your telling us why by responding to this thread.
Thank you!
[size=200][color=#FF0000]_______________________________________________________________[/color][/size]
[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=25535][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]
[hr][/hr]
[c][url=http://apod.nasa.gov/apod/ap111009.html][size=150][b]Nobels for a Strange Universe (2011 Oct 09)[/b][/size][/url][/c]
[float=left][img6="Image Credit: High-Z Supernova Search Team, HST, NASA"]http://apod.nasa.gov/apod/image/1110/sn94d_highz_900.jpg[/img6][hr][/hr][/float]Thirteen years ago [url=http://adsabs.harvard.edu/abs/1998AAS...193.3904A]results[/url] were [url=http://adsabs.harvard.edu/abs/1998AJ....116.1009R]first presented[/url] indicating that most of the energy in our universe is not in stars or galaxies but is tied to space itself. In the language of cosmologists, a large [url=http://super.colorado.edu/~michaele/Lambda/lambda.html]cosmological constant[/url] is directly implied by new distant [url=http://imagine.gsfc.nasa.gov/docs/science/know_l2/supernovae.html]supernova[/url] observations. Suggestions of a [url=http://en.wikipedia.org/wiki/Cosmological_constant]cosmological constant[/url] (lambda) were [url=http://relativity.livingreviews.org/Articles/lrr-2001-1/]not new[/url] -- they have existed since the advent of [url=http://www.astro.ucla.edu/~wright/cosmolog.htm]modern relativistic cosmology[/url]. Such claims were not usually popular with astronomers, though, because lambda is so unlike known [url=http://adsabs.harvard.edu/abs/2008ApJ...685.1297P]universe components[/url], because lambda's value appeared limited by other observations, and because less-[url=http://apod.nasa.gov/apod/ap071021.html]strange cosmologies[/url] without lambda had previously done well in explaining the data. What is noteworthy here is the seemingly direct and reliable method of the observations and the good reputations of the [url=http://cfa-www.harvard.edu/oir/Research/supernova/highz/members.html]scientists conducting[/url] [url=http://panisse.lbl.gov/public/]the investigations[/url]. Over the [url=http://apod.nasa.gov/apod/ap980302.html]past thirteen years[/url], independent teams of astronomers have continued to accumulate data that appears to [url=http://apod.nasa.gov/apod/ap050925.html]confirm[/url] the existence of [url=http://en.wikipedia.org/wiki/Dark_energy]dark energy[/url] and the unsettling result of a presently [url=http://en.wikipedia.org/wiki/Accelerating_universe]accelerating universe[/url]. This year, the team leaders were [url=http://www.nytimes.com/2011/10/05/science/space/05nobel.html]awarded the Nobel Prize in Physics[/url] for their work. The [url=http://www.cfa.harvard.edu/supernova//highz/figures/pictures.html]above picture[/url] of a supernova that occurred in [url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998AGM....14..P95D]1994[/url] on the outskirts of a [url=http://apod.nasa.gov/apod/spiral_galaxies.html]spiral galaxy[/url] was taken by one of these collaborations.
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[c][url=http://apod.nasa.gov/apod/ap111010.html][size=150][b]A Strange Sunrise Over Argentina (2011 Oct 10)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Luis Argerich"]http://apod.nasa.gov/apod/image/1110/strangesunrise_argerich_900.jpg[/img6][hr][/hr][/float][url=http://asterisk.apod.com/discuss_apod.php?date=111010]Why would a rising Sun look so strange?[/url] No one is yet sure. What is clear is that the above unusual sunrise was captured last month from [url=http://en.wikipedia.org/wiki/Buenos_Aires]Buenos Aires[/url], [url=http://en.wikipedia.org/wiki/Argentina]Argentina[/url]. The body of water in the foreground is [url=http://en.wikipedia.org/wiki/Rio_de_La_Plata]Rio de La Plata[/url], considered by many to be the widest river in the world. Although the [url=http://www.luisargerich.com/optiscapes/h1b5f4fbc#h1b5f4fbc]above image[/url] is actually a combination of a normal and a very short exposure needed to avoid [url=http://farm1.static.flickr.com/13/15029998_fb5890e7d1.jpg]oversaturating[/url] the bright Sun, the photographer saw this unusual structure with his own eyes, indicating that this effect was caused by neither [url=http://apod.nasa.gov/apod/ap090804.html]reflections[/url] nor [url=http://apod.nasa.gov/apod/ap101207.html]distortions[/url] in the camera or lens. What looks like arms on this [url=http://apod.nasa.gov/apod/ap110425.html]monster illusion[/url] might actually be, for example, low level clouds just thick enough to scatter sunlight without completely [url=http://apod.nasa.gov/apod/ap110115.html]blocking the Sun[/url]. Additionally, the distortion visible on the lower part of the Sun's image might indicate a [url=http://apod.nasa.gov/apod/ap090223.html]Etruscan Vase[/url] or [url=http://en.wikipedia.org/wiki/Fata_Morgana_%28mirage%29]Fata Morgana[/url] mirage possibly created by a curious [url=http://apod.nasa.gov/apod/%20http://physics.stackexchange.com/questions/10464/why-does-the-road-look-like-its-wet-on-hot-days]refracting layer of air[/url] over the water. Unusual [url=http://www.atoptics.co.uk/opod.htm]atmospheric phenomena[/url] are frequently [url=http://www.youtube.com/watch?v=Rh2tzXvBlJg]thrilling to see[/url] personally, and although most can be [url=http://apod.nasa.gov/apod/ap041207.html]traced to well known phenomena[/url], others, for lack of more data, [url=http://apod.nasa.gov/apod/ap070815.html]remain mysterious[/url].
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[c][url=http://apod.nasa.gov/apod/ap111011.html][size=150][b]NGC 7635: The Bubble Nebula (2011 Oct 11)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Larry Van Vleet"]http://apod.nasa.gov/apod/image/1110/bubble_vanvleet_900.jpg[/img6][hr][/hr][/float]It's the bubble versus the cloud. NGC 7635, the [url=http://apod.nasa.gov/apod/ap091030.html]Bubble Nebula[/url], is being pushed out by the [url=http://apod.nasa.gov/apod/ap000318.html]stellar wind[/url] of massive central star [url=http://adsabs.harvard.edu/abs/2002AJ....124.3305M]BD+602522[/url]. Next door, though, lives a giant [url=http://apod.nasa.gov/apod/ap090623.html]molecular cloud[/url], visible to the right. At this place in space, an [url=http://en.wikipedia.org/wiki/Irresistible_force_paradox]irresistible force[/url] meets an [url=http://1.bp.blogspot.com/-s8wPzTQVHwk/TZ23dhVwPTI/AAAAAAAAARY/1SsZ9s_A_J4/s1600/big+pumpkin.jpg]immovable object[/url] in an interesting way. The [url=http://heritage.stsci.edu/1998/31/index.html]cloud[/url] is able to contain the expansion of the bubble gas, but gets blasted by the hot radiation from the [url=http://www.exploratorium.edu/ronh/bubbles/bubbles.html]bubble[/url]'s central star. The [url=http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html]radiation[/url] heats up dense regions of the [url=http://en.wikipedia.org/wiki/Molecular_cloud]molecular cloud[/url] causing it to glow. The [url=http://apod.nasa.gov/apod/ap030617.html]Bubble Nebula[/url], [url=http://apod.nasa.gov/apod/]pictured above[/url] in scientifically mapped colors to bring up contrast, is about 10 [url=http://chandra.harvard.edu/photo/cosmic_distance.html]light-years[/url] across and part of a much [url=http://apod.nasa.gov/apod/ap100909.html]larger complex[/url] of stars and shells. The [url=http://apod.nasa.gov/apod/ap000118.html]Bubble Nebula[/url] can be seen with a small telescope towards the [url=http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html]constellation[/url] of the Queen of [url=http://en.wikipedia.org/wiki/Ethiopia_(mythology)]Aethiopia[/url] ([url=http://www.astronomical.org/portal/modules/wfsection/article.php?articleid=18]Cassiopeia[/url]).
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[c][url=http://apod.nasa.gov/apod/ap111012.html][size=150][b]Saturn: Shadows of a Seasonal Sundial (2011 Oct 12)[/b][/size][/url][/c]
[float=left][img6="Image Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA"]http://apod.nasa.gov/apod/image/1110/saturn9_cassini_900.jpg[/img6][hr][/hr][/float]Saturn's rings form one of the larger sundials known. This [url=http://en.wikipedia.org/wiki/Sundial]sundial[/url], however, determines only the [url=http://apod.nasa.gov/apod/ap030405.html]season[/url] of Saturn, not the time of day. In 2009, during [url=http://apod.nasa.gov/apod/ap090825.html]Saturn's last equinox[/url], Saturn's thin rings threw [url=http://apod.nasa.gov/apod/ap091110.html]almost no shadows[/url] onto Saturn, since the ring plane pointed directly toward the Sun. As Saturn continued in its orbit around the Sun, however, the ring shadows become increasingly wider and cast further south. These shadows are not easily visible from the Earth because from our vantage point near the Sun, the rings [url=http://addictedtoinsight.com/aihome/wp-content/uploads/2011/08/frustration1.png]always block[/url] the shadows. The [url=http://photojournal.jpl.nasa.gov/catalog/PIA14576]above image[/url] was taken in August by the [url=http://saturn.jpl.nasa.gov/spacecraft/overview/]robotic Cassini spacecraft[/url] currently orbiting Saturn. The rings themselves appear as a vertical bar on the image right. The Sun, far to the upper right, shines through the rings and casts captivatingly [url=http://apod.nasa.gov/apod/ap101012.html]complex shadows[/url] on south Saturn, on the image left. Cassini has been [url=http://apod.nasa.gov/apod/ap110613.html]exploring Saturn[/url], its rings, and its moons since 2004, and is [url=http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20100203/]expected to continue[/url] until at least the maximum elongation of Saturn's shadows occurs in 2017.
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[c][url=http://apod.nasa.gov/apod/ap111013.html][size=150][b]The Color of IC 1795 (2011 Oct 13)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Bob and Janice Fera (Fera Photography)"]http://apod.nasa.gov/apod/image/1110/Ngc896dBig_fera900c.jpg[/img6][hr][/hr][/float][url=http://www.feraphotography.com/AM14/Ngc896.html]This sharp cosmic portrait[/url] features [url=http://www-ssg.sr.unh.edu/ism/what1.html]glowing gas and obscuring dust[/url] clouds in IC 1795, a star forming region in the northern constellation [url=http://chandra.harvard.edu/photo/constellations/cassiopeia.html]Cassiopeia[/url]. Also cataloged as NGC 896, the nebula's remarkable details, shown in its dominant red color, were captured using a sensitive camera, and long exposures that include image data from a narrowband filter. The narrow filter transmits only [url=http://en.wikipedia.org/wiki/H-alpha]H-alpha light[/url], the red light of hydrogen atoms. Ionized by ultraviolet light from energetic young stars, a hydrogen atom emits the characteristic H-alpha light as its single electron is recaptured and transitions to lower energy states. Not far on the sky from the famous [url=http://apod.nasa.gov/apod/ap101014.html]Double Star Cluster[/url] in Perseus, IC 1795 is itself located next to IC 1805, the [url=http://apod.nasa.gov/apod/ap090214.html]Heart Nebula[/url], as part of a [url=http://www.atlasoftheuniverse.com/nebulae/ic1805.html]complex of star forming regions[/url] that lie at the edge of a large molecular cloud. Located just over 6,000 light-years away, the larger star forming complex sprawls along the Perseus spiral arm of our [url=http://apod.nasa.gov/apod/ap080606.html]Milky Way Galaxy[/url]. At that distance, this picture would span about 70 light-years across IC 1795.
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[c][url=http://apod.nasa.gov/apod/ap111014.html][size=150][b]MAGIC Star Trails (2011 Oct 14)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Babak Tafreshi (TWAN)"]http://apod.nasa.gov/apod/image/1110/MagicTrails_tafreshi.jpg[/img6][hr][/hr][/float]Colorful [url=http://www.twanight.org/newTWAN/photos.asp?ID=3003395]star trails[/url] arc across the night in this surreal [url=http://www.twanight.org/newTWAN/photos.asp?ID=3003384]timelapse[/url] skyscape from the [url=http://apod.nasa.gov/apod/ap110730.html]Roque de los Muchachos[/url] Observatory on the Canary island of La Palma. [url=http://apod.nasa.gov/apod/ap070519.html]A reflection[/url] of the Earth's daily rotation on its axis, the star trails are also reflected in one of a pair of 17 meter diameter, multi-mirrored [url=http://wwwmagic.mppmu.mpg.de/index.en.html]MAGIC telescopes[/url]. The MAGIC (Major Atmospheric Gamma Imaging Cherenkov) [url=http://www.magic.iac.es/webcams/]telescope itself[/url] is intended to detect gamma rays - photons with over 100 billion times the energy of visible light. As the high energy gamma rays impact the upper atmosphere they produce [url=http://imagine.gsfc.nasa.gov/docs/science/how_l2/cerenkov.html]air showers of high-energy particles[/url]. A fast camera monitoring the multi-mirrored surface records [url=http://wwwmagic.mppmu.mpg.de/introduction/event_sequence.gif]in detail[/url] brief flashes of optical light, called [url=http://wwwmagic.mppmu.mpg.de/introduction/iact.html]Cherenkov light, created by[/url] the air shower particles Astronomers can then ultimately relate the optical flashes to [url=http://wwwmagic.mpp.mpg.de/physics/recent/Crab/]cosmic sources[/url] of extreme gamma-rays.
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[c][url=http://apod.nasa.gov/apod/ap111015.html][size=150][b]NGC 4565: Galaxy on Edge (2011 Oct 15)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Bob Franke"]http://apod.nasa.gov/apod/image/1110/ngc4565_franke.jpg[/img6][hr][/hr][/float]Magnificent spiral galaxy [url=http://www.seds.org/messier/xtra/ngc/n4565.html]NGC 4565[/url] is viewed edge-on from planet Earth. Also known as the [url=http://apod.nasa.gov/apod/ap990617.html]Needle Galaxy[/url] for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation [url=http://www.dibonsmith.com/com_con.htm]Coma Berenices[/url]. [url=http://bf-astro.com/ngc4565/ngc4565.htm]This sharp, colorful image[/url] reveals the galaxy's bulging central core cut by obscuring [url=http://apod.nasa.gov/apod/ap070729.html]dust lanes[/url] that lace NGC 4565's [url=http://apod.nasa.gov/apod/ap100225.html]thin galactic plane[/url]. An assortment of other background galaxies is included in the pretty field of view, with neighboring galaxy NGC 4562 at the lower right. NGC 4565 itself lies about 40 million [url=http://chandra.harvard.edu/photo/cosmic_distance.html]light-years[/url] distant and spans some 100,000 light-years. Easily spotted with small telescopes, [url=http://www.cloudynights.com/item.php?item_id=1059]sky enthusiasts[/url] consider [url=http://www.noao.edu/outreach/aop/observers/n4565.html]NGC 4565[/url] to be a prominent celestial masterpiece [url=http://apod.nasa.gov/apod/ap080419.html]Messier missed[/url].
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[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=25535][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]