Tuesday, June 27, 2017

Kepler Finds 219 New Exoplanets

This is the most comprehensive and detailed catalog release of candidate exoplanets, which are planets outside our solar system, from Kepler's first four years of data. It's also the final catalog from the spacecraft's view of the patch of sky in the Cygnus constellation.

NASA's Kepler space telescope team has released a mission catalog of planet candidates that introduces 219 new planet candidates, 10 of which are near-Earth size and orbiting in their star's habitable zone, which is the range of distance from a star where liquid water could pool on the surface of a rocky planet.

With the release of this catalog, derived from data publically available on the NASA Exoplanet Archive, there are now 4,034 planet candidates identified by Kepler. Of which, 2,335 have been verified as exoplanets. Of roughly 50 near-Earth size habitable zone candidates detected by Kepler, more than 30 have been verified.

Monday, June 26, 2017

The SETI Decrypt Challenge

Decryption of Messages from Extraterrestrial Intelligence Using the Power of Social Media - The SETI Decrypt Challenge


Heller et al

With the advent of modern astronomy, humans might now have acquired the technological and intellectual requirements to communicate with other intelligent beings beyond the solar system, if they exist. Radio signals have been identified as a means for interstellar communication about 60 years ago. And the Square Kilometer Array will be capable of detecting extrasolar radio sources analogous to terrestrial high-power radars out to several tens of light years. The ultimate question is: will we be able to understand the message, or, vice versa, if we submit a message to extraterrestrial intelligence first, how can we make sure that they understand us? Here I report on the largest blind experiment of a pretend radio message received on Earth from beyond the solar system. I posted a sequence of about two million binary digits ("0" and "1") to the social media that encoded a configuration frame, two slides with mathematical content, and four images along with spatial and temporal information about their contents. Six questions were asked that would need to be answered to document the successful decryption of the message. Within a month after the posting, over 300 replies were received in total, including comments and requests for hints, 66 of which contained the correct solutions. About half of the solutions were derived fully independently, the other half profited from public online discussions and spoilers. This experiment demonstrates the power of the world wide web to help interpreting possible future messages from extraterrestrial intelligence and to test decryptability of our own deliberate interstellar messages.

Saturday, June 24, 2017

ALMA Detects Debris Disk Around Fomalhaut

An international team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has made the first complete millimeter-wavelength image of the ring of dusty debris surrounding the young star Fomalhaut. This remarkably well-defined band of rubble and gas is likely the result of exocomets smashing together near the outer edges of a planetary system 25 light-years from Earth.

Earlier ALMA observations of Fomalhaut -- taken in 2012 when the telescope was still under construction - revealed only about one half of the debris disk. Though this first image was merely a test of ALMA's initial capabilities, it nonetheless provided tantalizing hints about the nature and possible origin of the disk.


Monday, June 19, 2017

Is there anybody out there?

Is there anybody out there?


Anchordoqui et al


The Fermi paradox is the discrepancy between the strong likelihood of alien intelligent life emerging (under a wide variety of assumptions) and the absence of any visible evidence for such emergence. We use this intriguing unlikeness to derive an upper limit on the fraction of living intelligent species that develop communication technology \langle \xi_{\rm biotec} \rangle. \langle \cdots \rangle indicates average over all the multiple manners civilizations can arise, grow, and develop such technology, starting at any time since the formation of our Galaxy in any location inside it. Following Drake, we factorize \langle \xi_{\rm biotec} \rangle as the product of the fractions in which: (i) life arises, (ii) intelligence develops, and (iii) communication technology is developed. In this approximation, the number of communicating intelligent civilizations that exist in the Galaxy at any given time is found to be N = \langle \zeta_{\rm astro} \rangle \langle \xi_{\rm biotec} \rangle L_\tau, where \langle \zeta_{\rm astro} \rangle is the average production rate of potentially habitable planets with a long-lasting (\sim 4 Gyr) ecoshell and L_\tau is the length of time that a typical civilization communicates. We estimate the production rate of exoplanets in the habitable zone and using recent determinations of the rate of gamma-ray bursts (GRBs) and their luminosity function, we calculate the probability that a life-threatening (lethal) GRB could make a planet inhospitable to life, yielding \langle \zeta_{\rm astro} \rangle \sim 2 \times 10^{-3}. Our current measurement of N =0 then implies \langle \zeta_{\rm biotec} \rangle < 5 \times 10^{-3} at the 95\% C.L., where we have taken L_\tau > 0.3 Myr such that c L_\tau >> propagation distances of Galactic scales (\sim 10 kpc), ensuring that any advanced civilization living in the Milky Way would be able to communicate with us.

Sunday, June 18, 2017

ALMA Finds Organic Compounds in Protoplanetary Disks

Two teams of astronomers have harnessed the power of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to detect the prebiotic complex organic molecule methyl isocyanate [1] in the multiple star system IRAS 16293-2422. One team was co-led by Rafael Martín-Doménech at the Centro de Astrobiología in Madrid, Spain, and Víctor M. Rivilla, at the Osservatorio Astrofisico di Arcetri in Florence, Italy; and the other by Niels Ligterink at the Leiden Observatory in the Netherlands and Audrey Coutens at University College London, United Kingdom.

"This star system seems to keep on giving! Following the discovery of sugars, we've now found methyl isocyanate. This family of organic molecules is involved in the synthesis of peptides and amino acids, which, in the form of proteins, are the biological basis for life as we know it," explain Niels Ligterink and Audrey Coutens [2].

Friday, June 16, 2017

Trappist-1e Among Initial Observational Targets for the James Webb Space Telescope

Mission officials for NASA's James Webb Space Telescope announced some of the science targets the telescope will observe following its launch and commissioning. These specific observations are part of a program of Guaranteed Time Observations (GTO), which provides dedicated time to the scientists that helped design and build the telescope's four instruments.

"From the very first galaxies after the Big Bang, to searching for chemical fingerprints of life on Enceladus, Europa, and exoplanets like TRAPPIST-1e, Webb will be looking at some incredible things in our universe," said Eric Smith, James Webb Space Telescope Director at NASA Headquarters in Washington. "With over 2100 initial observations planned, there is no limit to what we might discover with this incredible telescope."

Monday, June 12, 2017

Are Niven Rings Around Pulsars Detectable?

Are the Dyson rings around pulsars detectable?



In the previous paper (Osmanov 2016) (henceforth Paper-I) we have extended the idea of Freeman Dyson and have shown that a supercivilization has to use ring-like megastructures around pulsars instead of a spherical shell. In this work we reexamine the same problem in the observational context and we show that facilities of modern IR telescopes (VLTI and WISE) might efficiently monitor the nearby zone of the solar system and search for the IR Dyson-rings up to distances of the order of 0.2kpc, corresponding to the current highest achievable angular resolution, 0.001mas. In this case the total number of pulsars in the observationally reachable area is about 64±21. We show that pulsars from the distance of the order of ∼1kpc are still visible for WISE as point-like sources but in order to confirm that the object is the neutron star, one has to use the UV telescopes, which at this moment cannot provide enough sensitivity.