Discoveries using the telescopes on Mauna Kea

[TomK]

Lowest ever mass binary system discovered

When I started my career in astronomy, brown dwarfs were purely hypothetical as telescopes and instrumentation weren't sensitive enough to detect them. However, in the last couple od decades, such objects seem to be commonplace, with perhaps 100 billion of them in the Galaxy alone. However, most are observed as members of binary systems (which makes them easier to detect). Then there the oddballs, free-floating brown dwarfs which aren't part of a system; IIRC, UKIRT was the first to discover these objects.

Now the Kecks on MK have been used to discover what was thought to be a free-floating brown dwarf is actually a binary system consisting of two objects with a little less than four Jupiter masses each, making this the least massive binary system known. With such small masses, they are too small to undergo nuclear fusion in their cores and are heated mainly by the forces of gravitational collapse, just like Jupiter.

http://aasnova.org/2017/07/05/discovery-...le-planet/

[TomK]

A bizarre new exoplanet

This one is very strange, I'm not sure I believe the numbers at the moment. Using Kepler data followed up by both Subaru and Keck observations (both on MK), the new exoplanet orbits a star a little over 300 light years from Earth. It's so close to the star that it orbits every 4.5 hours (which is unusual in itself).

The really weird thing is that the planet appears to be slightly smaller than the Earth but might have the mass approaching that of Jupiter, meaning it is incredibly dense. Although it appears to be roughly the size of Earth, if you were to attempt to stand on its surface you'd end up as flat as a pancake.

https://phys.org/news/2017-07-astronomer...bital.html

[HereOnThePrimalEdge]

* Planet orbits its sun every 4.5 hours
* Planet is small & massive

Quite a lot of speculation is possible with those few facts. Is the planet composed of metals as a partial explanation for its mass? With its size and the rapid speed of its orbit, would it generate some kind of electrical field? How far away could any measurable effects of this system be detected?

So much to discover and study out in the final frontier. Thanks for the updates TomK.

Four people are in a room and seven leave. How many have to enter again before it's empty?

[PaulW]

Even in my pancake-like state I would be impressed by the 4 seasons lasting just over an hour each.

[TomK]

The mass seemed a bit ridiculous to me (there's no metal I know that could account for such a mass of an Earth-sized planet) so read the actual paper to get the details. The mass mentioned is simply an upper limit to what they can measure and used that to determine it's a planetary-mass object and not something more exotic. The actual mass is likely to be very much lower, probably close to Earth's. However, they did determine that it has an iron core much more massive than the Earth's, so is likely a little more massive and dense.

As for the orbit, that's much easier to determine and is pretty accurate, so yes, assuming it has an axial tilt, you'll get all four seasons in just over four hours! As it orbits about 500 thousand miles from the star though, they'll all be very hot seasons...

[Earth orbits about 90 million miles from the sun].

[TomK]

"Discovery of a rare quadruple gravitational lens candidate with Pan-STARRS"

This discovery was first made by the Pan-STARRS survey on Maui's Haleakala and then confirmed by the Keck observatory on MK. It's a distant quasar (an active galaxy with a massive black hole producing energy thousands of times greater than our Galaxy) and often they look similar to stars in a basic astronomical image.

In this case, the gravitation of an almost invisible galaxy between the quasar and the Earth has affected space-time enough that the light from the quasar has split into four distinct beams from our perspective, so a single point-source now appears as four separate objects. More info here:

https://phys.org/news/2017-07-discovery-...-lens.html

[TomK]

"Black-Hole Hunter Takes Aim at Einstein"

This is an interesting article/interview about work going on at the Keck Observatory on Mauna Kea. It involves the massive black hole at the center of our Galaxy. However, please be aware that the picture the article claims is the Keck Observatory most definitely isn't. It's a nice night-time shot of the UH Hilo Educational Telescope with UKIRT and the UH-2.2 meter telescope to the right.

https://www.quantamagazine.org/black-hol...-20170727/

[PaulW]

Interesting article, thanks Tom. Nice picture too, despite the caption!

[TomK]

"How Dust Built the Universe"

Another interesting article, this time highlighting the James Clerk Maxwell Telescope (JCMT) on Mauna Kea. This is a telescope I'm more than familiar with, and the role of dust, or more accurately soot, is something close to my own area of expertise(*) and it's the stuff we are made of. Not only does it play a large role in understanding observations at all sorts of wavelengths, it is crucial in the formation stars, planets, and life in the universe.

* "“Doing infrared astronomy from the ground is like trying to observe a star in the daylight out of a telescope made of light bulbs,” George Rieke, an infrared astronomer, once said."

http://www.pbs.org/wgbh/nova/next/physic...-universe/

[TomK]

I posted something about this event in the hurricane season 2017 thread, but it seems appropriate to post about it here. One of the Gemini North Cloud Cam cameras, used to monitor weather conditions, also captured a phenomenon which some are calling "gigantic jets", although I prefer the term "super sprite". These are electrical emissions that occur above a thunderstorm rather than the usual lightning that occurs within the cloud or goes between the cloud and the ground. This article includes a beautiful enhance image of the event from last week. These things are rare, so it's very unusual for an observatory on MK to capture such an image.

https://www.space.com/37650-jet-lightnin...video.html