Comments and questions about the
APOD on the main view screen.
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APOD Robot
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by APOD Robot » Wed Oct 04, 2017 4:07 am
The Soul Nebula in Infrared from Herschel
Explanation: Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the
Soul Nebula can be found in the direction of the
constellation Cassiopeia, who Greek mythology credits as the
vain wife of a King who long ago ruled
lands surrounding the
upper Nile river. The
Soul Nebula houses several open
clusters of stars, a large radio source known as
W5, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500
light years away, the Soul Nebula spans about 100 light years and is usually
imaged next to its celestial neighbor the
Heart Nebula (IC 1805). The
featured image, impressively detailed, was taken in several bands of
infrared light by the orbiting
Herschel Space Observatory.
[/b]
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Boomer12k
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by Boomer12k » Wed Oct 04, 2017 8:18 am
Bleh! (Said in my Vampire tone)....
dhe ghooostly shapes of the SOOOOUUULLL Nebuuula.... in infrared....
Spoooooky....The "Soul Cavern"....
Get on board the Soul Train....
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Camiel
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by Camiel » Wed Oct 04, 2017 9:42 am
Seems very unlikely that (late) Herschel has taken the picture last month! :^)
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Case
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by Case » Wed Oct 04, 2017 11:17 am
Camiel wrote:Seems very unlikely that (late) Herschel has taken the picture last month! :^)
Wikipedia wrote:Friedrich Wilhelm Herschel (15 November 1738 – 25 August 1822) was a British astronomer and composer of German and Czech-Jewish origin, and brother of fellow astronomer Caroline Herschel, with whom he worked. […] On 11 February 1800, Herschel was testing filters for the sun so he could observe sun spots. When using a red filter he found there was a lot of heat produced. Herschel discovered infrared radiation in sunlight by passing it through a prism and holding a thermometer just beyond the red end of the visible spectrum. This thermometer was meant to be a control to measure the ambient air temperature in the room. He was shocked when it showed a higher temperature than the visible spectrum. Further experimentation led to Herschel's conclusion that there must be an invisible form of light beyond the visible spectrum.
ESA wrote:The Herschel Space Observatory was launched on 14 May 2009 and observed the sky for almost four years, until its coolant ran out on 29 April 2013.
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BDanielMayfield
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by BDanielMayfield » Wed Oct 04, 2017 1:06 pm
So, since this is an infrared image, what we are seeing here is warm gas or dust of various temperatures regardless of composition, or do the different colors show areas of different elements?
Bruce
Just as zero is not equal to infinity, everything coming from nothing is illogical.
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Chris Peterson
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by Chris Peterson » Wed Oct 04, 2017 1:57 pm
BDanielMayfield wrote:So, since this is an infrared image, what we are seeing here is warm gas or dust of various temperatures regardless of composition, or do the different colors show areas of different elements?
At these long wavelengths (70 μm and 100 μm) we're just seeing the thermal emissions of cool dust (30-40 K). I don't think we can infer anything about composition.
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BDanielMayfield
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by BDanielMayfield » Wed Oct 04, 2017 2:20 pm
Chris Peterson wrote:BDanielMayfield wrote:So, since this is an infrared image, what we are seeing here is warm gas or dust of various temperatures regardless of composition, or do the different colors show areas of different elements?
At these long wavelengths (70 μm and 100 μm) we're just seeing the thermal emissions of cool dust (30-40 K). I don't think we can infer anything about composition.
Thanks for confirming what I was thinking Chris.
Just as zero is not equal to infinity, everything coming from nothing is illogical.
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neufer
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by neufer » Wed Oct 04, 2017 3:17 pm
Art Neuendorffer
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RJN
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by RJN » Wed Oct 04, 2017 3:41 pm
A representative of ESA contacted me by email to say that this Herschel image was not taken last month. It was taken in 2013 but released last month. In fact, the Herschel spacecraft, out of helium coolant, has ceased scientific operations and been in a parking orbit for the past four years. Please see:
http://www.esa.int/Our_Activities/Opera ... ng_testbed for more information. The NASA APOD text has now been updated. I apologize for not keeping better track of Herschel's status, and for the oversight in the APOD text.
- RJN
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Chris Peterson
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by Chris Peterson » Wed Oct 04, 2017 4:05 pm
RJN wrote:I apologize for not keeping better track of Herschel's status, and for the oversight in the APOD text.
It is a positive sign of our times that there are so many space-based observatories now that keeping track of them all has become a significant chore!
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Boomer12k
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by Boomer12k » Wed Oct 04, 2017 9:28 pm
My pereidohlia kicking in... the right "SIDE" in blue... reminds me of a Mandelbrot set...especially when looking at a smaller picture.
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MarkBour
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by MarkBour » Wed Oct 04, 2017 11:30 pm
Chris Peterson wrote:RJN wrote:I apologize for not keeping better track of Herschel's status, and for the oversight in the APOD text.
It is a positive sign of our times that there are so many space-based observatories now that keeping track of them all has become a significant chore!
Agreed! On the downside, though, I wonder will there come a day when we will need a rule, such as: "You can't launch another unless you fetch and return one."
Mark Goldfain
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Ann
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by Ann » Wed Oct 04, 2017 11:50 pm
MarkBour wrote:Chris Peterson wrote:RJN wrote:I apologize for not keeping better track of Herschel's status, and for the oversight in the APOD text.
It is a positive sign of our times that there are so many space-based observatories now that keeping track of them all has become a significant chore!
Agreed! On the downside, though, I wonder will there come a day when we will need a rule, such as: "You can't launch another unless you fetch and return one."
Good idea. Otherwise we might not be able to see the Universe for all the space junk orbiting in front of it.
Ann
Color Commentator
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Chris Peterson
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by Chris Peterson » Thu Oct 05, 2017 12:02 am
Ann wrote:MarkBour wrote:Chris Peterson wrote:
It is a positive sign of our times that there are so many space-based observatories now that keeping track of them all has become a significant chore!
Agreed! On the downside, though, I wonder will there come a day when we will need a rule, such as: "You can't launch another unless you fetch and return one."
Good idea. Otherwise we might not be able to see the Universe for all the space junk orbiting in front of it.
It's going to be a long time before space observatories are numerous enough to become a significant part of the space junk problem!
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neufer
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by neufer » Thu Oct 05, 2017 2:56 am
Chris Peterson wrote:
It's going to be a long time before space observatories are numerous enough to become a significant part of the space junk problem!
https://en.wikipedia.org/wiki/Herschel_Space_Observatory wrote:
<<The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was the largest infrared telescope ever launched, carrying a 3.5-metre mirror and instruments sensitive to the far infrared and submillimetre wavebands (55–672 µm). The observatory was carried into orbit in May 2009, reaching the second Lagrangian point (L2) of the Earth–Sun system about two months later.
On 29 April 2013, ESA announced that Herschel's supply of liquid helium, used to cool the instruments and detectors on board, had been depleted, thus ending its mission. At the time of the announcement, Herschel was approximately 1.5 million km from Earth. Because Herschel's orbit at the L2 point is unstable, ESA wanted to guide the craft on a known trajectory. ESA managers considered two options:
- 1. Place Herschel into a Heliocentric orbit where it would not encounter Earth for at least several hundred years.
2. Guide Herschel on a course toward the Moon for a destructive high-speed collision that would help in the search for water at a lunar pole. Herschel would take about 100 days to reach the Moon.
The managers chose the first option because it was less costly.
On 17 June 2013, Herschel was fully deactivated, with its fuel tanks forcibly depleted and the onboard computer programmed to cease communications with Earth. The final command, which severed communications, was sent from European Space Operations Centre (ESOC) at 12:25 UTC. The mission's post-operations phase will continue until 2017. The main tasks are consolidation and refinement of instrument calibration, to improve data quality, and data processing, to create a body of scientifically validated data.>>
Art Neuendorffer
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MargaritaMc
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by MargaritaMc » Thu Oct 05, 2017 6:17 am
JPL did a nice resumé of the achievements of the Herschel Space Observatory
https://www.jpl.nasa.gov/news/news.php?feature=6952
SEPTEMBER 22, 2017
Legacy of Herschel Space Observatory
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS
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neufer
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by neufer » Thu Oct 05, 2017 12:14 pm
Assuming that Planet 9 is internally heated like Neptune and is running a temperature ~50 K
HSO might have been useful in the current search by making use of ~60 micrometer IR.
Art Neuendorffer
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MargaritaMc
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by MargaritaMc » Thu Oct 05, 2017 8:04 pm
neufer wrote:
Assuming that Planet 9 is internally heated like Neptune and is running a temperature ~50 K
HSO might have been useful in the current search by making use of ~60 micrometer IR.
The Planet Nine temperature estimate by Linder et al* is 47K, so the Herschel Space Observatory might indeed have been useful...
*E. F. Linder et al. Evolution and magnitudes of candidate planet nine, Astronomy & Astrophysics (2016). DOI: 10.1051/0004-6361/201628350
https://www.aanda.org/articles/aa/abs/2 ... 50-16.html
https://m.phys.org/news/2016-04-planet.html
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS
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BDanielMayfield
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by BDanielMayfield » Sat Oct 07, 2017 12:50 pm
It's ironic that so much is known about an unknown planet.
Bruce
Just as zero is not equal to infinity, everything coming from nothing is illogical.
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neufer
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by neufer » Sat Oct 07, 2017 1:45 pm
BDanielMayfield wrote:
It's ironic that so much is known about an unknown planet.
Much is surmised about a planet that is assumed to be a distant relative of Neptune.
Neptune Diagram.
Upper atmosphere, top clouds. Atmosphere consisting of hydrogen, helium, and methane gas. Mantle consisting of water, ammonia, and methane ices. Core consisting of rock (silicates and nickel-iron).
Art Neuendorffer
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MarkBour
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by MarkBour » Fri Oct 13, 2017 3:19 am
Chris Peterson wrote:Ann wrote:MarkBour wrote:
Agreed! On the downside, though, I wonder will there come a day when we will need a rule, such as: "You can't launch another unless you fetch and return one."
Good idea. Otherwise we might not be able to see the Universe for all the space junk orbiting in front of it.
It's going to be a long time before space observatories are numerous enough to become a significant part of the space junk problem!
But bear in mind that I'm wondering about a particular case in space junkology. I'm wondering how many objects at L2 it would take before L2 became "crowded". But in this case, I see that they did not leave Herschel at L2. And if they had, I wonder if it would have remained right there, or would have wandered away on its own over time (years, not millenia).
Mark Goldfain