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posted by cmn32480 on Tuesday November 14 2017, @06:41AM   Printer-friendly
from the there-is-a-poop-joke-here-someplace dept.

Scientists have used the Spitzer Space Telescope to find a possible exoplanet or brown dwarf candidate, OGLE-2016-BLG-1190Lb, around 22,000 light years away near the center of the Milky Way galaxy. Spitzer is currently using transit photometry and gravitational microlensing to find exoplanets, a use the telescope wasn't originally designed for. Spitzer recently discovered five of the seven exoplanets around TRAPPIST-1 using the transit photometry method.

OGLE-2016-BLG-1190Lb is likely to be the first exoplanet Spitzer has found in the Milky Way's Galactic bulge using gravitational microlensing. At an estimated 13.4 ± 0.9 Jupiter masses, the object is right near the deuterium burning limit, the boundary dividing large gas giants from brown dwarfs.

The paper explains the significance of the discovery:

The discovery of Spitzer microlensing planet OGLE-2016-BLG-1190Lb is remarkable in five different respects. First, it is the first planet in the Spitzer Galactic-distribution sample that likely lies in the Galactic bulge, which would break the trend from the three previous members of this sample. Second, it is precisely measured to be right at the edge of the brown dwarf desert. Since the existence of the brown dwarf desert is the signature of different formation mechanisms for stars and planets, the extremely close proximity of OGLE-2016-BLG-1190Lb to this desert raises the question of whether it is truly a "planet" (by formation mechanism) and therefore reacts back upon its role tracing the Galactic distribution of planets, just mentioned above. Third, it is the first planet to enter the Spitzer "blind" sample whose existence was recognized prior to its choice as a Spitzer target. This seeming contradiction was clearly anticipated by Yee et al. (2015b) when they established their protocols for the Galactic distribution experiment. The discovery therefore tests the well-defined, but intricate procedures devised by Yee et al. (2015b) to deal with this possibility. Fourth, it is the first planet (and indeed the first microlensing event) for which the well-known microlens-parallax degeneracy has been broken by observations from two satellites. Finally, it is the first microlensing planet for which a complete orbital solution has been attempted. While this attempt is not completely successful in that a one-dimensional degeneracy remains, it is an important benchmark on the road to such solutions.

Also at Newsweek and BGR.

OGLE-2016-BLG-1190Lb: First Spitzer Bulge Planet Lies Near the Planet/Brown-Dwarf Boundary

Related: Seven Earth-Sized Exoplanets, Including Three Potentially Habitable, Identified Around TRAPPIST-1
Scientists Improve Brown Dwarf Weather Forecasts

Original Submission

Related Stories

Seven Earth-Sized Exoplanets, Including Three Potentially Habitable, Identified Around TRAPPIST-1 41 comments

Astronomers have observed enough planetary transits to confirm the existence of seven "Earth-sized" exoplanets orbiting TRAPPIST-1, an ultra-cool (~2550 K) red dwarf star about 39.5 light years away. Three of the exoplanets are located inside the "habitable zone" of their parent star. These three orbit from 0.028 to 0.045 AU away from the star:

Astronomers using the TRAPPIST–South telescope at ESO's La Silla Observatory, the Very Large Telescope (VLT) at Paranal and the NASA Spitzer Space Telescope, as well as other telescopes around the world, have now confirmed the existence of at least seven small planets orbiting the cool red dwarf star TRAPPIST-1. All the planets, labelled TRAPPIST-1b, c, d, e, f, g and h in order of increasing distance from their parent star, have sizes similar to Earth.

The exoplanets are presumed to be tidally locked. The six closest to TRAPPIST-1 have been determined to be rocky, while the seventh, TRAPPIST-1h, requires additional observations to determine its characteristics due to its longer orbital period.

Mass estimates for the planets range from 0.41 Earth masses (M) to 1.38 M. Radii range from 0.76 Earth radii (R) to 1.13 R.

Spitzer, Hubble, and other telescopes will continue to make observations of the TRAPPIST-1 planetary system, but the best data will likely come from the James Webb Space Telescope (JWST), which is scheduled to launch in late 2018. JWST will allow the atmospheres and temperatures of many exoplanets to be characterized, which will help to settle whether the "habitable zones" of red dwarf stars are actually hospitable.

Artist illustrations and data for the TRAPPIST-1 system compared to Mercury, Venus, Mars, and Earth.

Here's a website dedicated to the star.

Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1 (DOI: 10.1038/nature21360) (DX)

Original Submission

Scientists Improve Brown Dwarf Weather Forecasts 6 comments

[Researchers] have a new model for explaining how clouds move and change shape in brown dwarfs, using insights from NASA's Spitzer Space Telescope. Giant waves cause large-scale movement of particles in brown dwarfs' atmospheres, changing the thickness of the silicate clouds, researchers report in the journal Science. The study also suggests these clouds are organized in bands confined to different latitudes, traveling with different speeds in different bands.

"This is the first time we have seen atmospheric bands and waves in brown dwarfs," said lead author Daniel Apai, associate professor of astronomy and planetary sciences at the University of Arizona in Tucson.

[...] "The atmospheric winds of brown dwarfs seem to be more like Jupiter's familiar regular pattern of belts and zones than the chaotic atmospheric boiling seen on the Sun and many other stars," said study co-author Mark Marley at NASA's Ames Research Center in California's Silicon Valley.

Zones, spots, and planetary-scale waves beating in brown dwarf atmospheres (DOI: 10.1126/science.aam9848) (DX)

Original Submission

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  • (Score: 2) by frojack on Tuesday November 14 2017, @06:54AM (4 children)

    by frojack (1554) Subscriber Badge on Tuesday November 14 2017, @06:54AM (#596694) Journal

    Why are they wasting their time ogling stars 22,000 light years away near the center of the Milky Way galaxy. Have they suddenly and secretly invented warp drive or something? Have they exhausted all the life-time-reachable stars?

    Stars Stars within 12 Light years of earth. []

    No, you are mistaken. I've always had this sig.
    • (Score: 2) by takyon on Tuesday November 14 2017, @07:29AM

      by takyon (881) Subscriber Badge <reversethis-{gro ... s} {ta} {noykat}> on Tuesday November 14 2017, @07:29AM (#596699) Journal

      I assumed they are systematically using the gravitational microlensing [] technique on thousands of nearby objects, and just happened to get a view of something 22,000 light years away in this case.

      Since microlensing observations do not rely on radiation received from the lens object, this effect therefore allows astronomers to study massive objects no matter how faint. It is thus an ideal technique to study the galactic population of such faint or dark objects as brown dwarfs, red dwarfs, planets, white dwarfs, neutron stars, black holes, and massive compact halo objects. Moreover, the microlensing effect is wavelength-independent, allowing use of distant source objects that emit any kind of electromagnetic radiation.

      Search for "Spitzer Galactic-distribution sample" []

      I think what's going on here is that they are aiming Spitzer at objects between Spitzer and the galactic bulge, with the expectation that there is a higher chance of detecting stuff in the bulge using microlensing since the matter is packed closer together.

      [SIG] 10/28/2017: Soylent Upgrade v14 []
    • (Score: 3, Informative) by takyon on Tuesday November 14 2017, @08:54AM

      by takyon (881) Subscriber Badge <reversethis-{gro ... s} {ta} {noykat}> on Tuesday November 14 2017, @08:54AM (#596716) Journal

      Here's a story about a Spitzer/OGLE microlensing exoplanet that was found a bit closer: []

      The technique works better when aimed at the bulge:

      Astronomers are using these blips to find and characterize planets tens of thousands of light-years away in the central bulge of our galaxy, where star crossings are more common.

      Spitzer's distance from Earth allows objects to be located using Spitzer + an Earth based observatory:

      Of the approximately 30 planets discovered with microlensing so far, roughly half cannot be pinned down to a precise location. The result is like a planetary treasure map lacking in X's.

      That's where Spitzer can help out, thanks to its remote Earth-trailing orbit. Spitzer circles our sun, and is currently about 128 million miles (207 million kilometers) away from Earth. That's farther from Earth than Earth is from our sun. When Spitzer watches a microlensing event simultaneously with a telescope on Earth, it sees the star brighten at a different time, due to the large distance between the two telescopes and their unique vantage points. This technique is generally referred to as parallax.

      You asked why they are looking at stars so far away instead of the ones close up. It's because they want to know about the distribution of objects in the center of our galaxy:

      "We've mainly explored our own solar neighborhood so far," said Sebastiano Calchi Novati, a Visiting Sagan Fellow at NASA's Exoplanet Science Institute at the California Institute of Technology, Pasadena. "Now we can use these single lenses to do statistics on planets as a whole and learn about their distribution in the galaxy."

      For all we know, there are less planets in the galactic center because they interact gravitationally with other stars more often, smash into each other and stars/brown dwarfs, etc.

      Also, there's no hurry to observe our solar neighborhood. We have new telescopes coming up in the next 20 years that are going to provide the exoplanet data we really crave: atmospheric and even biosphere detection. JWST [], WFIRST [], ATLAST []/LUVOIR [] (whatever it ends up getting called, basically a more direct successor to Hubble than JWST), FINESSE [], etc. will provide this data.

      Don't forget that Spitzer is being used on targets closer to home. It discovered five [] of the seven known TRAPPIST-1 [] exoplanets (39.5 light years away).

      [SIG] 10/28/2017: Soylent Upgrade v14 []
    • (Score: 1, Funny) by Anonymous Coward on Tuesday November 14 2017, @09:19AM

      by Anonymous Coward on Tuesday November 14 2017, @09:19AM (#596718)

      I think it is because once I took a brown dwarf from the near neighborhood, and I tacked it to the side of our shed. Some 8 years later, when we finally moved from that house, the brown dwarf was still attached to the side the shed, and showed no signs of bio-degradation, or of running out of dueterium, for that matter. This is when I thought it might be a good idea to look at some brown dwarfs a bit further afield.

    • (Score: 2) by takyon on Wednesday November 15 2017, @03:28AM

      by takyon (881) Subscriber Badge <reversethis-{gro ... s} {ta} {noykat}> on Wednesday November 15 2017, @03:28AM (#597124) Journal

      If you include brown dwarfs along with stars (not on your link), Luhman 16 [] is the 3rd closest system (6.5 ly), discovered just in 2010 (announced in 2013). WISE 0855−0714 [] is a sub-brown dwarf (rogue planet) and the 4th closest system (7.3 ly). Finally there is WISE 1506+7027 [] and WISE 0350−5658 [] as well as some brown dwarfs orbiting normal stars.

      Brown dwarfs can have protoplanetary disks. Maybe even life in a subsurface ocean on a planet/moon orbiting it.

      [SIG] 10/28/2017: Soylent Upgrade v14 []
  • (Score: 1, Interesting) by Anonymous Coward on Tuesday November 14 2017, @10:23AM (2 children)

    by Anonymous Coward on Tuesday November 14 2017, @10:23AM (#596730)

    So (brown) dwarves are bigger than (gas) giants.

    • (Score: 2) by takyon on Tuesday November 14 2017, @10:35AM (1 child)

      by takyon (881) Subscriber Badge <reversethis-{gro ... s} {ta} {noykat}> on Tuesday November 14 2017, @10:35AM (#596733) Journal

      I wonder how different things would have been on Earth (assuming something like it could survive in the habitable zone) if there had been 15 Jupiter masses ~5.2 AU from the Sun instead of... 1 Jupiter mass [].

      Earth and its neighbor planets may have formed from fragments of planets after collisions with Jupiter destroyed those super-Earths near the Sun. As Jupiter came toward the inner Solar System, in what theorists call the Grand Tack Hypothesis, gravitational tugs and pulls occurred causing a series of collisions between the super-Earths as their orbits began to overlap.

      Astronomers have discovered nearly 500 planetary systems with multiple planets. Regularly these systems include a few planets with masses several times greater than Earth's (super-Earths), orbiting closer to their star than Mercury is to the Sun, and sometimes also Jupiter-mass gas giants close to their star.

      Jupiter moving out of the inner Solar System would have allowed the formation of inner planets, including Earth.

      [SIG] 10/28/2017: Soylent Upgrade v14 []
      • (Score: 3, Informative) by PartTimeZombie on Tuesday November 14 2017, @10:20PM

        by PartTimeZombie (4827) on Tuesday November 14 2017, @10:20PM (#597016)

        It is one of the interesting whatifs about our solar system.

        There seem to be a huge number of variables that make life on Earth possible, and just one small change in the early formation of the whole set up might have meant life never got started, or maybe got started but then snuffed out, (Mars being a possible candidate for that).

        Planet having a magnetic field

        Also having a carbon cycle

        Also a large moon

        Being in the goldilocks zone of its parent star

        Having a gas giant (or two) far enough away to not perturb the orbit, but big enough to catch (at least some) of the big rocks that might cause trouble.

        The fact that we know so little about other solar systems means there might be a whole bunch of other things that got life started in the other places too.