Discoveries using the telescopes on Mauna Kea

[TomK]

Kronos - devourer of planets.

Observations using the Keck Observatory on Mauna Kea have discovered that a star is likely "eating" rocky planets in its solar system. The star was nicknamed "Kronos" after the Greek divine being who devoured his children.

https://phys.org/news/2017-10-devourer-p...ronos.html

"Other processes that change the abundance of elements generically throughout the galaxy don't give you a trend like that," said Price-Whelan. "They would selectively enhance certain elements, and it would appear random if you plotted it versus condensation temperatures. The fact that there's a trend there hinted towards something related to planet formation rather than galactic chemical evolution."

That was her "Aha!" moment, Oh said. "All of the elements that would make up a rocky planet are exactly the elements that are enhanced on Kronos, and the volatile elements are not enhanced, so that provides a strong argument for a planet engulfment scenario, instead of something else."

The Gemini and CFHT telescopes on Mauna Kea were both used recently to observe a very similar system in which a star seems to have ingested its own planets.

http://gemini.edu/node/12716

"Astronomers using the Gemini Observatory and the Canada-France-Hawaii Telescope have discovered remarkable differences in the abundance of heavier elements, and the Lithium content, in a binary star pair. The research team speculates that this difference is caused by the engulfment of rocky planets early in the system’s evolution which enriched one of the stars. The work also hints at a formation scenario resulting in gas giant planets forming relatively far from their host star."

[TomK]

"Discovery of the century"

I'm sure some of you have seen this in the news, but gravitational waves (or Einstein waves) have again been detected, this time from a likely collision between two neutron stars. The previous detection was from a pair of colliding black holes. Some are calling this "the discovery of the century" although personally, I think it's a little early in the century to make that claim. In any case, what makes this special is that the event was also observed at optical and infrared wavelengths, which means a whole new area of astrophysics has been opened up and whatever people say, it is an enormous and extremely significant discovery.

As for Hawaii telescopes, the Subaru on MK and Pan-STARRS on Haleakala were involved in the observations. More MK observatories may have also observed the event but I'm not sure about those details yet. In the meantime, the LIGO team published this web page of useful resources at:

http://www.gw.iucaa.in/news/gw170817/

[TomK]

Not really a discovery, but something about UH Hilo astronomy students learning how to make discoveries:

https://www.hawaii.edu/news/2017/10/17/s...hy-images/

[TomK]

I would love to summarize this, but I can't. I'll do my best albeit briefly.

UKIRT and other MK observatories have made some major discoveries about the so-called Unidentified Infrared band emission (UIRs). They can, sometimes, also be seen in absorption (i.e., they absorb light from a background source rather than emit the light on their own). These bands are generally seen in regions around old stars where many chemical processes are going on, aided by high-energy ultraviolet radiation from stars. Eventually you end up with these things called polycyclic aromatic hydrocarbons (PAHs). These are molecules that you create whenever you have a barbeque. All you need is carbon, hydrogen and a lot of energy (heat or UV radiation). Add a few more elements and you get some very interesting looking results which can be hard to interpret.

Now we get this, which, quite frankly, is not the way to excite the public. I'm not sure I understand the article myself. This is what you do to put people off science and astronomy.

"Wave nature of delocalized electrons in defective hydrocarbons at the origin of cosmic infrared emission"

https://phys.org/news/2017-10-nature-del...rbons.html

[PaulW]

Thanks, as always, TomK.

[TomK]

For those interested:

"Observatory director to talk about exoplanet system"

UKIRT has been observing the TRAPPIST-1 system for a while now. It's a solar system with seven planets with three in the "habitable zone" meaning they might support life. The planets are aligned in such a way they transit the star as well as transiting themselves which is has made things very interesting but also quite difficult to decipher.

Bob McLaren will be giving a talk at Imiloa.

http://hawaiitribune-herald.com/news/com...net-system

"A total of seven planets have been discovered around TRAPPIST-1 by using the transit technique, in which astronomers carefully measure the small dimming that occurs when one or more of the planets crosses in front of the star. With its sensitive infrared camera called the Wide Field Cam, UKIRT is able to measure the transit dimming with a photometric accuracy of 500 parts per million and a timing accuracy of 20 seconds.

McLaren will describe how UKIRT’s observations have played a major role in establishing the multiplanet nature of the TRAPPIST-1 system. He also will explain how these same observations revealed that all seven planets have masses close to that of Earth."

[PaulW]

http://abcnews.go.com/Technology/wireSto...r-51198889

Not MK (sorry) but it there is a Hawaii connection and even has a Hawaiian name: Oumuamua

[TomK]

Thanks for that, Paul. I've been on vacation with Pam for a while and haven't been updating the thread for a while but was going to post something about the comet, so thanks for saving me the time!

[PaulW]

Sure TomK, hope you two are having fun. Quick question - why are some calling this a comet? Don't you need more ice for that?

[TomK]

The problem is that it's not clear yet if it's a comet or an asteroid. When first discovered, it was thought to be a comet but recent observations have shown no activity or indications of ice on the surface. However, this doesn't rule out the possibility it's a comet as it's a long way from the sun so may not be active and the colors that suggest it doesn't have ice could be due to the ice being darkened by millions of years of photoprocessing by UV light. It has, though, recently been classified as an asteroid based on those colors, but it's not definite. Things should become a little clearer over the next few months.

ETA: The nature paper was embargoed so didn't have a chance to read it until just now. 'Oumuamua got within 0.25 AU of the sun (a quarter of the Sun-Earth distance - an AU is the average distance between the Sun and the Earth)) and showed no activity. Comets typically show some activity at about 3 AU and sometimes farther away. This seems to be fairly conclusive evidence that 'Oumuamua is an asteroid.