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Attempting to understand Io's volcanism
Io, one of Jupiter's major moons, has been known since Voyager 1's flyby in 1979 as volcanically active. The activity stems from tidal heating forces due to Jupiter and its other major moons, Europa and Ganymede, which keeps the interior of Io molten. More recent studies by Gemini and the Keck Observatories on Mauna Kea have shown volcanic activity on Io appears to cycle over a period of around 500 earth-days.
Io orbits Jupiter very quickly, in about 1.8 days, but it also has a longer period of around 480 days during which time its orbit changes. It's believed this long period cycle is responsible for the changes in Io's overall volcanic activity.
" By studying changes in Io’s surface brightness due to its volcanic activity, researchers discovered a pattern in the volcanism that appears to coincide with the 480-day variation in the moon’s orbital shape. This was unexpected because there is no detectable pattern associated with the 1.8-day period of a single orbit, even though this is the amount of time over which the most dramatic variations in the pull of gravity occur. To understand this puzzling result, the researchers note that the magma is likely too viscous to react to the changing gravity on the timescale of one orbit, but it can adjust its flow rate with the slower variation in the shape of Io’s orbit. This explains the long-term variations in the degree of volcanic activity."
https://www.gemini.edu/node/21215
More details can be found at
https://blogs.agu.org/geospace/2019/08/0...nic-tides/
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Planets behaving badly
https://phys.org/news/2019-08-newly-gian...-star.html
" This planet is unlike the planets in our solar system, but more than that, it is unlike any other exoplanets we have discovered so far," says Sarah Blunt, a Caltech graduate student and first author on the new study publishing in The Astronomical Journal. "Other planets detected far away from their stars tend to have very low eccentricities, meaning that their orbits are more circular. The fact that this planet has such a high eccentricity speaks to some difference in the way that it either formed or evolved relative to the other planets."
[...]
" Copernicus taught us that Earth is not the center of the solar system, and as we expanded into discovering other solar systems of exoplanets, we expected them to be carbon copies of our own solar system," Howard explains, "But it's just been one surprise after another in this field. This newfound planet is another example of a system that is not the image of our solar system but has remarkable features that make our universe incredibly rich in its diversity."
The Keck Observatory on MK contributed to the study.
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Additional news on the LIGO detection TomK posted a few weeks ago:
Possible Detection of a Black Hole So Big It ‘Should Not Exist’
Seven experts contacted by Quanta said they’d heard that among the 22 flurries of gravitational waves detected by LIGO and Virgo since April, one of the signals came from a collision involving a black hole of unanticipated heft — purportedly as heavy as 100 suns. LIGO/Virgo team members would neither confirm nor deny the rumored detection.
https://www.quantamagazine.org/possible-...-20190828/
"I'm at that stage in life where I stay out of discussions. Even if you say 1+1=5, you're right - have fun." - Keanu Reeves
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" Exoplanets Can’t Hide Their Secrets from Innovative New Instrument"
New technology and an old technique of observing stars, "speckle imaging", has enabled us to detect a Jupiter-like planet in a binary star system. Exoplanets orbiting binary star systems were thought rare years ago due to the instability caused by two stars in close orbit, but exoplanets have been observed in such systems. It's just very difficult to figure out which star they orbit.
This new technique, using the Gemini North telescope on MK has finally figured out that what was thought to be a low mass star or a brown dwarf was actually more like Jupiter because the planet's extended atmosphere attenuated blue light more than red light. Speckle imaging helped provide such high-resolution images to make this possible.
http://www.gemini.edu/node/21236
" “This dual win has elevated the importance of instruments like ‘Alopeke in exoplanet research,” said Chris Davis of the National Science Foundation, one of Gemini’s sponsoring agencies. “The exquisite seeing and telescope abilities of Gemini Observatory, as well as the innovative ‘Alopeke instrument made this discovery possible in merely four hours of observations.""
ETA: Incidentally, Chris Davis worked at UKIRT for many years.
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The team involved in imaging Powehi win "Breakthrough Award for Physics"
Among the winners of the 2020 Breakthrough Prize Foundation is the team that brought together radio and submillimeter observatories across the planet to create the first image of a black hole. Among those awarded the prize are several staff members at the Smithsonian Submillimeter Array and JCMT observatories on Mauna Kea.
https://gizmodo.com/scientists-behind-fi...1837900989
https://www.bbc.com/news/science-environment-49571917
https://www.theguardian.com/science/2019...sics-prize
https://www.newscientist.com/article/221...ole-photo/
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"Black hole at the center of our galaxy appears to be getting hungrier"
https://phys.org/news/2019-09-black-hole...grier.html
" "We have never seen anything like this in the 24 years we have studied the supermassive black hole," said Andrea Ghez, UCLA professor of physics and astronomy and a co-senior author of the research. "It's usually a pretty quiet, wimpy black hole on a diet. We don't know what is driving this big feast." "
...
"The researchers analyzed more than 13,000 observations of the black hole from 133 nights since 2003. The images were gathered by the W.M. Keck Observatory in Hawaii and the European Southern Observatory's Very Large Telescope in Chile."
...
"The new findings are based on observations of the black hole—which is called Sagittarius A*, or Sgr A*—during four nights in April and May at the Keck Observatory."
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The team that produced this study worked on the Einstein test I posted about previously.
What I find particularly cool is that the data these telescopes collect now (and have in the past) can contain hidden data in the noise that future technology / algorithms / AI etc... will be able to extract. An observation tonight might lead to an insight years from now -- because we have the data!
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" Gemini Observatory Captures Multicolor Image of First-ever Interstellar Comet"
This comet was mentioned in another thread yesterday, but the Gemini North North Observatory on Mauna Kea has produced the first multicolor images of a comet which appears to be of interstellar origin.
" “This image was possible because of Gemini’s ability to rapidly adjust observations and observe objects like this, which have very short windows of visibility,” said Andrew Stephens of Gemini Observatory who coordinated the observations. “However, we really had to scramble for this one since we got the final details at 3:00 am and were observing it by 4:45!”
The image shows a very pronounced tail, indicative of outgassing, which is what defines a cometary object. This is the first time an interstellar visitor to our Solar System has clearly shown a tail due to outgassing. The only other interstellar visitor studied in our Solar System was ‘Oumuamua which was a very elongated asteroid-like object with no obvious outgassing."
https://www.gemini.edu/node/21240
PS. Just to add to the above, the distance of the comet from the sun is about 3 AU (three times the distance of the earth from the sun) and this is a typical distance for comets to become active. Although not always the case, this distance is near enough to the sun for the volatile ices on the comet to be heated to the point they sublimate and create a tail, exactly what the current observations appear to show.
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A couple of follow-ups to two recent posts here:
" NASA visualization shows a black hole's warped world"
https://phys.org/news/2019-09-nasa-visua...arped.html
A simulation of the appearance of a black hole with matter falling into it looks very similar to the first image of a black hole, Powehi, a result that was produced using two Mauna Kea telescopes - https://www.hawaiitribune-herald.com/201...witnessed/
" Naming of new interstellar visitor: 2I/Borisov"
https://phys.org/news/2019-09-interstell...risov.html
Our second known interstellar visitor, after Oumuamua, which has been studied by the Gemini North Telescope on MK, has been named 2I/Borisov after the amateur astronomer who discovered it.
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Proto-Galactic cluster led to a lot of baby stars
A cluster of galaxies has been discovered that really shouldn't exist given the small amount of time they had to organize the party after the universe started. The event ended up with lots of baby stars being born. The discovery involves observations by several Mauna Kea observatories - Gemini, Subaru, Keck and UKIRT.
https://www.gemini.edu/node/21241
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Thanks Tom. With the comet being interstellar I assume that means it's moving much faster than normal comets do. In the unlikely event of an impact by such a thing, would that cause a lot more damage on Earth? Of course (I assume), we've always had interstellar visitors we just hadn't noticed them before?
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