Posts: 11,030
Threads: 751
Joined: Sep 2012
Nine or ten or twelve new moons have been discovered orbiting Jupiter (different numbers are being reported by various news organizations) The initial find was made at an observatory in Chile, but follow up observations also took place in Hawaii and Arizona. Gemini North Observatory On Mauna Kea took part in one of the more unusual findings:
Gemini North telescope in Hawaii... was used to confirm an oddball moon, named Valetudo after the Roman god Jupiter’s great-granddaughter, the goddess of health and hygiene. Valetudo is considered an oddball because of its inclined prograde orbit that crosses the paths of the outer retrograde moons.
“Our other discovery is a real oddball and has an orbit like no other known Jovian moon,” Sheppard explained. “It’s also likely Jupiter’s smallest known moon, being less than one kilometer in diameter”.
http://www.gemini.edu/node/21080
A bird flies home across the sky. It appears to be tired, it had a difficult day. It returns from the hunt, it was hunted. - Laszlo Krasznahorkai
"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
Posts: 10,239
Threads: 345
Joined: Apr 2009
Doppelganger exoplanet had a different upbringing
A doppelganger exoplanet has been discovered that looks identical to one of the most famous exoplanets known, beta Pictoris b, but it turns out the environment it's "twin" grew up in, 2MASS 0249 c (lovely name), is completely different. The work was carried out using the CFHT and Keck observatories on Mauna Kea.
http://www.ifa.hawaii.edu/info/press-rel...pelganger/
" Dupuy, Liu, and their collaborators have identified the first case of such a planetary doppelgänger. One object has long been known: the 13-Jupiter-mass planet beta Pictoris b, one of the first planets discovered by direct imaging, back in 2009. The new object, dubbed 2MASS 0249 c, has the same mass, brightness, and spectrum as beta Pictoris b."
[...]
" However, the planets have vastly different living situations, namely the types of stars they orbit. The host for beta Pictoris b is a star 10 times brighter than the Sun, while 2MASS 0249 c orbits a pair of brown dwarfs that are 2000 times fainter than the Sun. Furthermore, beta Pictoris b is relatively close to its host, about 9 astronomical units (AU, the distance from the Earth to the Sun), while 2MASS 0249 c is 2000 AU from its binary host."
Posts: 10,239
Threads: 345
Joined: Apr 2009
" Young Galaxy’s Halo Offers Clues to its Growth and Evolution"
A study using a new instrument at the Keck Observatory on Mauna Kea has just been published. Astronomers using an integral field unit (IFU) on the Keck Cosmic Web Imager (KCWI) studied a young galaxy about 10 billion light-years away to try and understand how gas surrounding the galaxy in a halo effects star formation. Halo gas moving away from the galaxy removes material that can form stars, whereas gas moving into the galaxy provides the birth material and may also trigger star formation.
An IFU is a great piece of technology, something I've used myself in the past. It lets you take spectral images, i.e., you get images of an object at several wavelengths and at the same time get spectra from every bit of that image allowing you to combine imaging and spectroscopy in one shot. In this case, the astronomers concentrated on Lyman Alpha emission from hydrogen surrounding the galaxy. This will go a long way in understanding how early galaxies formed and developed into galaxies such as our own.
http://www.keckobservatory.org/gas_halo/
Posts: 10,239
Threads: 345
Joined: Apr 2009
Very much related to the above:
" New Keck Observatory Instrument to Zero In On What Is Stunting Galaxy Growth"
http://www.keckobservatory.org/agn/
" Astronomers are using a powerful new probe at W. M. Keck Observatory to investigate what’s causing galaxies to stop forming new stars. It’s one of the biggest mysteries in astronomy today and Dr. Alison Coil of University of California, San Diego is among the astronomers who are on a mission to find out."
[...]
"Coil is using KCWI to gather observational evidence necessary to support the theory that supermassive black holes cause a chain reaction in their host galaxy that ceases new star formation. This theory has currently only been proposed through computer modeling and remains to be proven with observational data."
Posts: 10,239
Threads: 345
Joined: Apr 2009
" Enduring ‘radio rebound’ powered by jets from gamma-ray burst"
Gamma Ray Bursts, extremely energetic events typically seen billions of light years away and when the universe was much younger, are believed to be due to the collapse of a massive star at the end of its life leaving a black hole in its place - the former core of the star which collapsed in in on itself due to its own gravity.
In this particular case, observed using UKIRT on Mauna Kea and a number of other telescopes around the planet at various wavelengths, GRB 161219B exploded and sent its outer layers into space. This time, however, the outflow hit dense regions of gas and a shock wave was sent back along the outflow. The radio detections of this event were sonified to a frequency human ears can hear:
https://news.northwestern.edu/stories/20...ray-burst/
UKIRT is still working with Northwestern astronomers on follow-ups on other new GRB as well as the infamous AT2018cow supernova.
Posts: 10,239
Threads: 345
Joined: Apr 2009
Apologies, not strictly Hawaii related, but I came across this tonight, a live stream of a National Geographic documentary about astronomy. It's been live streaming for a few days so I'm guessing it repeats, so it's easy to watch a bit and then watch another bit later.
Thought one or two people here would be interested especially given how important Hawaii is to astronomy:
https://youtu.be/EdAt5pWZulE
Posts: 2,402
Threads: 145
Joined: Apr 2005
Oh this is so fascinating to the lay person who doesn't even know the words. But thank you for sharing this. When I look at the artistic rendition it comes to my minds eye that perhaps the black hole accretion disk is the big bang and the jet streams are expelling streams of new galaxies. Fascinating as fascinating as the earth rebirthing itself. The National Geographic youtube link is exceptional too!
quote:
Originally posted by TomK
Very much related to the above:
"New Keck Observatory Instrument to Zero In On What Is Stunting Galaxy Growth"
http://www.keckobservatory.org/agn/
"[i]Astronomers are using a powerful new probe at W. M. Keck
"Coil is using KCWI to gather observational evidence necessary to support the theory that supermassive black holes cause a chain reaction in their host galaxy that ceases new star formation. This theory has currently only been proposed through computer modeling and remains to be proven with observational data."
mella l
Art and Science
bytheSEA
mella l
Art and Science
bytheSEA
Posts: 10,239
Threads: 345
Joined: Apr 2009
Mella,
Think of things on a smaller scale. Black holes aren't creating new galaxies but are creating conditions to create stars to form within their own galaxy - it's complicated but can describe the process if you want. I'm not sure what you mean by earth rebirthing, but please feel free to ask questions and I'll answer them the best way I can.
Tom
Posts: 10,239
Threads: 345
Joined: Apr 2009
OK, three items today so each will be brief especially as I've had a busy day!
1) " IfA Graduate BJ Fulton Receives Prestigious Trumpler Award"
http://www.ifa.hawaii.edu/info/press-rel...er_fulton/
Dr. Fulton was awarded a prestigious science prize for his PhD thesis using the Keck Observatory on Mauna Kea. His work shows there is a gap between the size of rocky planets and those made primarily of gas, such as Jupiter or Saturn. This gap was known about in our own solar system but it now seems as though it also exists in other planetary systems which indicates some very fundamental process is in play.
2) The Great Void
https://phys.org/news/2018-08-massive-re...axies.html
OK, that sounds a little Star Trekish, but astronomers using the Subaru telescope on MK have found a vast region of space which is relatively opaque to light. I'm still struggling to understand this and haven't read the paper yet, but the idea is that for some reason there's a lack of galaxies in this region which means neutral gas can form in the area and block light. I need to read a little more about this as it was my understanding that neutral gas was less opaque compared to ionized gas, but am going back to my old undergraduate days from decades ago...
3) The Earth is Quite Normal
https://phys.org/news/2018-08-material-d...ients.html
More from observations carried out using the Keck Observatory. It's not that surprising given that we know that the physics and chemistry in our Galaxy is pretty much the same wherever you look, but it's reassuring to find that exoplanets roughly the size of Earth appear to have very similar compositions to our planet and of course raises hope that the circumstances that give rise to life may be ubiquitous.
Posts: 5,640
Threads: 101
Joined: Dec 2008
Thanks TomK, very interesting reading.
|
