Showing posts with label LHS 1140b. Show all posts
Showing posts with label LHS 1140b. Show all posts

Saturday, June 20, 2020

CfA Scientists Collaborate on New Study to Search the Universe for Signs of Technological Civilizations

Artist's impression of the exoplanet LHS 1140b, which orbits its star within the "habitable zone" where liquid water might exist on the surface. The LHS 1140 system is only about 40 light-years from Earth, making it a possible target for studying the atmosphere of the planet if it has one. Credit: M. Weiss/CfA.
Low Resolution (jpg)

Cambridge, MA - Scientists at the Center for Astrophysics | Harvard & Smithsonian and the University of Rochester are collaborating on a project to search the universe for signs of life via technosignatures, after receiving the first NASA non-radio technosignatures grant ever awarded, and the first SETI-specific NASA grant in over three decades.

Researchers believe that although life appears in many forms, the scientific principles remain the same, and that the technosignatures identifiable on Earth will also be identifiable in some fashion outside of the solar system. "Technosignatures relate to signatures of advanced alien technologies similar to, or perhaps more sophisticated than, what we possess," said Avi Loeb, Frank B. Baird Jr. Professor of Science at Harvard. "Such signatures might include industrial pollution of atmospheres, city lights, photovoltaic cells (solar panels), megastructures, or swarms of satellites."

Knowing where to look for technosignatures hasn't always been easy, making it difficult for researchers to obtain grants and a footing in mainstream astronomy. The surge of results in exoplanetary research—including planets in habitable zones and the presence of atmospheric water vapor—over the past five years has revitalized the search for intelligent life. "The Search for Extraterrestrial Intelligence (SETI) has always faced the challenge of figuring out where to look. Which stars do you point your telescope at and look for signals?" said Adam Frank, a professor of physics and astronomy at the University of Rochester, and the primary recipient of the grant. "Now we know where to look. We have thousands of exoplanets including planets in the habitable zone where life can form. The game has changed."

The study, "Characterizing Atmospheric Technosignatures," will initially focus on searching for two particular signatures that may indicate the presence of technological activities on extrasolar planetary bodies: solar panels and pollutants.

Solar panels are rapidly gaining in popularity as a means for harnessing the energy of Earth's sun, and researchers believe other civilizations will do the same with their own stars as they seek new means to produce energy. "The nearest star to Earth, Proxima Centauri, hosts a habitable planet, Proxima b. The planet is thought to be tidally locked with permanent day and night sides," said Loeb. "If a civilization wants to illuminate or warm up the night side, they would place photovoltaic cells on the day side and transfer the electric power gained to the night side." Frank added, "Our job is to say, 'this wavelength band' is where you would see sunlight reflected off solar panels. This way astronomers observing a distant exoplanet will know where and what to look for if they’re searching for technosignatures."

In the search for life outside of the solar system, scientists also often turn to biosignatures detected as chemicals in planetary atmospheres. Jason Wright, Penn State University, said, “We have come a long way toward understanding how we might detect life on other worlds from the gases present in those worlds’ atmospheres." While scientists can search for those chemicals produced naturally by life, like methane, they are now also searching for artificial chemicals and gases. "We pollute Earth’s atmosphere with our industrial activity," said Loeb. “If another civilization had been doing it for much longer than we have, then their planet's atmosphere might show detectable signs of artificially produced molecules that nature is very unlikely to produce spontaneously, such as chlorofluorocarbons (CFCs)." The presence of CFCs—or refrigerant—therefore, could indicate the presence of industrial activity.

Loeb, Frank, and Wright are joined by Mansavi Lingam of the Florida Institute of Technology, and Jacob Haqq-Misra of Blue Marble Space. The study aims to eventually produce the first entries for an online technosignatures library.

"My hope is that, using this grant, we will quantify new ways to probe signs of alien technological civilizations that are similar to or much more advanced than our own," said Loeb. "The fundamental question we are trying to address is: are we alone? But I would add to that: even if we are alone right now, were we alone in the past?"



About Center for Astrophysics | Harvard & Smithsonian

Headquartered in Cambridge, Mass., the Center for Astrophysics | Harvard & Smithsonian (CfA) is a collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.



For more information, contact:

Amy Oliver
Public Affairs
Center for Astrophysics | Harvard & Smithsonian
Fred Lawrence Whipple Observatory
520-879-4406

amy.oliver@cfa.harvard.edu


Sunday, September 03, 2017

Ultraviolet Light May Be Ultra Important In Search For Life

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.



For more information, contact:

Megan Watzke
Harvard-Smithsonian Center for Astrophysics
+1 617-496-7998

mwatzke@cfa.harvard.edu

Peter Edmonds
Harvard-Smithsonian Center for Astrophysics
+1 617-571-7279

pedmonds@cfa.harvard.edu


Thursday, April 20, 2017

Newly Discovered Exoplanet May be Best Candidate in Search for Signs of Life


Artist’s impression of the super-Earth exoplanet LHS 1140b

Location of the faint red star LHS 1140 in the constellation of Cetus (The Sea Monster)

PR Image eso1712c
 Artist’s impression of the newly-discovered rocky exoplanet, LHS 1140b 


Videos

Artist’s impression of a trip to the super-Earth exoplanet LHS 1140b
Artist’s impression of a trip to the super-Earth exoplanet LHS 1140b



Transiting rocky super-Earth found in habitable zone of quiet red dwarf star

An exoplanet orbiting a red dwarf star 40 light-years from Earth may be the new holder of the title “best place to look for signs of life beyond the Solar System”. Using ESO’s HARPS instrument at La Silla, and other telescopes around the world, an international team of astronomers discovered a “super-Earth” orbiting in the habitable zone around the faint star LHS 1140. This world is a little larger and much more massive than the Earth and has likely retained most of its atmosphere. This, along with the fact that it passes in front of its parent star as it orbits, makes it one of the most exciting future targets for atmospheric studies. The results will appear in the 20 April 2017 issue of the journal Nature.

The newly discovered super-Earth LHS 1140b orbits in the habitable zone around a faint red dwarf star, named LHS 1140, in the constellation of Cetus (The Sea Monster) [1]. Red dwarfs are much smaller and cooler than the Sun and, although LHS 1140b is ten times closer to its star than the Earth is to the Sun, it only receives about half as much sunlight from its star as the Earth and lies in the middle of the habitable zone. The orbit is seen almost edge-on from Earth and as the exoplanet passes in front of the star once per orbit it blocks a little of its light every 25 days.

This is the most exciting exoplanet I’ve seen in the past decade,” said lead author Jason Dittmann of the Harvard-Smithsonian Center for Astrophysics (Cambridge, USA). “We could hardly hope for a better target to perform one of the biggest quests in science — searching for evidence of life beyond Earth.

"The present conditions of the red dwarf are particularly favourable — LHS 1140 spins more slowly and emits less high-energy radiation than other similar low-mass stars," explains team member Nicola Astudillo-Defru from Geneva Observatory, Switzerland [2].

For life as we know it to exist, a planet must have liquid surface water and retain an atmosphere. When red dwarf stars are young, they are known to emit radiation that can be damaging for the atmospheres of the planets that orbit them. In this case, the planet's large size means that a magma ocean could have existed on its surface for millions of years. This seething ocean of lava could feed steam into the atmosphere long after the star has calmed to its current, steady glow, replenishing the planet with water.

The discovery was initially made with the MEarth facility, which detected the first telltale, characteristic dips in light as the exoplanet passed in front of the star. ESO’s HARPS instrument, the High Accuracy Radial velocity Planet Searcher, then made crucial follow-up observations which confirmed the presence of the super-Earth. HARPS also helped pin down the orbital period and allowed the exoplanet’s mass and density to be deduced [3].

The astronomers estimate the age of the planet to be at least five billion years. They also deduced that it has a diameter 1.4 times larger than the Earth — almost 18 000 kilometres. But with a mass around seven times greater than the Earth, and hence a much higher density, it implies that the exoplanet is probably made of rock with a dense iron core.

This super-Earth may be the best candidate yet for future observations to study and characterise its atmosphere, if one exists. Two of the European members of the team, Xavier Delfosse and Xavier Bonfils both at the CNRS and IPAG in Grenoble, France, conclude: “The LHS 1140 system might prove to be an even more important target for the future characterisation of planets in the habitable zone than Proxima b or TRAPPIST-1. This has been a remarkable year for exoplanet discoveries![4,5].

In particular, observations coming up soon with the NASA/ESA Hubble Space Telescope will be able to assess exactly how much high-energy radiation is showered upon LHS 1140b, so that its capacity to support life can be further constrained.

Further into the future — when new telescopes like ESO’s Extremely Large Telescope are operating — it is likely that we will be able to make detailed observations of the atmospheres of exoplanets, and LHS 1140b is an exceptional candidate for such studies.



Notes

[1] The habitable zone is defined by the range of orbits around a star, for which a planet possesses the appropriate temperature needed for liquid water to exist on the planet’s surface.

[2] Although the planet is located in the zone in which life as we know it could potentially exist, it probably did not enter this region until approximately forty million years after the formation of the red dwarf star. During this phase, the exoplanet would have been subjected to the active and volatile past of its host star. A young red dwarf can easily strip away the water from the atmosphere of a planet forming within its vicinity, leading to a runaway greenhouse effect similar to that on Venus.

[3] This effort enabled other transit events to be detected by MEarth so that the astronomers could nail down the detection of the exoplanet once and for all.

[4] The planet around Proxima Centauri (eso1629) is much closer to Earth, but it probably does not transit its star, making it very difficult to determine whether it holds an atmosphere.

[5] Unlike the TRAPPIST-1 system (eso1706), no other exoplanets around LHS 1140 have been found. Multi-planet systems are thought to be common around red dwarfs, so it is possible that additional exoplanets have gone undetected so far because they are too small.



More Information


This research was presented in a paper entitled “A temperate rocky super-Earth transiting a nearby cool star”, by J. A. Dittmann et al. to appear in the journal Nature on 20 April 2017.

The team is composed of Jason A. Dittmann (Harvard Smithsonian Center for Astrophysics, USA), Jonathan M. Irwin (Harvard Smithsonian Center for Astrophysics, USA), David Charbonneau (Harvard Smithsonian Center for Astrophysics, USA), Xavier Bonfils (Institut de Planétologie et d'Astrophysique de Grenoble – Université Grenoble-Alpes/CNRS, France), Nicola Astudillo-Defru (Observatoire de Genève, Switzerland), Raphaëlle D. Haywood (Harvard Smithsonian Center for Astrophysics, USA), Zachory K. Berta-Thompson (University of Colorado, USA), Elisabeth R. Newton (MIT, USA), Joseph E. Rodriguez (Harvard Smithsonian Center for Astrophysics, USA), Jennifer G. Winters (Harvard Smithsonian Center for Astrophysics, USA), Thiam-Guan Tan (Perth Exoplanet Survey Telescope, Australia), José-Manuel Almenara (Institut de Planétologie et d'Astrophysique de Grenoble - Université Grenoble-Alpes/CNRS, France; Observatoire de Genève, Switzerland), François Bouchy (Aix Marseille Université, France), Xavier Delfosse (Institut de Planétologie et d'Astrophysique de Grenoble – Université Grenoble-Alpes / CNRS, France), Thierry Forveille (Institut de Planétologie et d'Astrophysique de Grenoble – Université Grenoble-Alpes/CNRS, France), Christophe Lovis (Observatoire de Genève, Switzerland), Felipe Murgas (Institut de Planétologie et d'Astrophysique de Grenoble – Université Grenoble-Alpes / CNRS, France; IAC, Spain), Francesco Pepe (Observatoire de Genève, Switzerland), Nuno C. Santos (Instituto de Astrofísica e Ciências do Espaço and Universidade do Porto, Portugal), Stephane Udry (Observatoire de Genève, Switzerland), Anaël Wünsche (CNRS/IPAG, France), Gilbert A. Esquerdo (Harvard Smithsonian Center for Astrophysics, USA), David W. Latham (Harvard Smithsonian Center for Astrophysics, USA) and Courtney D. Dressing (Caltech, USA).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.
 


Links



Contacts

Jason Dittmann
Harvard-Smithsonian Center for Astrophysics
Cambridge, USA
Email: jdittmann@cfa.harvard.edu

Nicola Astudillo-Defru
Geneva Observatory - Université of Geneva
Geneva, Switzerland
Email: nicola.astudillo@unige.ch

Xavier Bonfils
Institut de Planétologie et d'Astrophysique de Grenoble – Université Grenoble-Alpes/CNRS
Grenoble, France
Email: xavier.bonfils@univ-grenoble-alpes.fr

Richard Hook
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

Megan Watzke
Harvard-Smithsonian Center for Astrophysics
Cambridge, USA
Tel: +1 617-496-7998
Email: mwatzke@cfa.harvard.edu

Source: ESO