Red Dots: The Live Search for Terrestrial Planets around Proxima Centauri Continues

The team behind the Pale Red Dot campaign, who last year discovered a planet around the closest star to our Sun (eso1629), are resuming their search for Earth-like planets and launching another initiative today. The Red Dots campaign will follow the astronomers as they use ESO’s exoplanet-hunter to look for planets around some of our nearest stellar neighbours: Proxima Centauri, Barnard’s Star and Ross 154. ESO is joining this Open Notebook Science experiment — real science presented in real time — that will give the public and the scientific community access to observational data from Proxima Centauri as the campaign unfolds.

The scientific team [1] led by Guillem Anglada-Escudé from Queen Mary University of London will acquire and analyse data from ESO’s High Accuracy Radial velocity Planet Searcher (HARPS) and other instruments across the globe [2] over approximately 90 nights. Photometric observations began on 15 June and spectrographic observations start on 21 June.

HARPS is a spectrograph with unrivalled precision — the most successful finder of low-mass exoplanets to date. Attached to the ESO 3.6-metre telescope at La Silla, HARPS searches nightly for exoplanets, looking for the minute wobbles in the star’s motion generated by the pull of an exoplanet in orbit. HARPS picks up motion which can be as little as a gentle walking pace — just 3.5 km/h — from trillions of kilometres away.

Among the stars targeted by Red Dots will be Proxima Centauri, which scientists suspect has more than one terrestrial planet in orbit around it. Proxima Centauri is the closest star to our Sun, only 4.2 light-years away. It may be one of the most suitable places to look for life beyond our Solar System, as our instruments and technologies advance.

Earlier this year, ESO announced a partnership with the Breakthrough Initiatives, which aims to demonstrate proof of concept for a new technology that will enable ultra-light unmanned space flight at 20% of the speed of light. Such nanocraft could be sent to the three stars of the Alpha Centauri system, of which Proxima Centauri is the closest to our Sun.

The other two stars observed during the Red Dots campaign are Barnard’s star, a low mass red dwarf almost 6 light-years away, and Ross 154, another red dwarf, 9.7 light-years away. Barnard’s star is a popular star in science fiction culture and has also been proposed as the target for future interstellar missions such as the Daedalus project.

The telescope observations will be complemented by an outreach campaign supported by ESO and other partners [3]. The Pale Red Dot campaign revealed the methods and steps of doing science, but the results were presented only after the peer review process. This time, observational data from Proxima Centauri will be revealed, analysed and discussed in real time.

Pro-am collaborations and contributions by interested citizens and scientists will be encouraged via social media and a forum tool, as well as via support tools from the American Association of Variable Star Observers (AAVSO).

Any observations presented during this time will of course be preliminary only and they must not be used or cited in refereed literature. The team will not produce conclusive statements, nor claim any finding until a suitable paper is written, peer-reviewed and accepted for publication.

The Red Dots campaign will keep the public informed via the reddots.space website, where weekly updates will be posted, together with supporting articles and highlights of the week including featured contributions by the community. Conversations will take place also on the Red Dots Facebook page, the Red Dots Twitter account and the hashtag #reddots.

No one can say for sure what the outcome of the Red Dots campaign will be. After data acquisition and data analysis together with the community, the scientific team will submit the results for formal peer review. If exoplanets are indeed discovered around these stars, ESO’s Extremely Large Telescope, due to see first light in 2024, should be able to directly image them and characterise their atmospheres, a crucial step towards searching for evidence of life beyond the Solar System.

Notes

[1] The team of astronomers leading the observations and outreach campaign are: Guillem Anglada-Escudé, John Strachan, Richard P. Nelson, Harriet Brettle (Queen Mary University of London, UK), John Barnes (Open University, UK), Mikko Tuomi, Hugh R. A. Jones (University of Hertfordshire, UK), Cristina Rodríguez-Lopez, Eloy Rodriguez, Pedro J. Amado, María J. López-González, Nicolás Morales, José Luís Ortiz (Instituto de Astrofisica de Andalucia, Spain), Enric Pallé, Victor J. Sanchez Bejar, Felipe Murgas (Instituto de Astrofísica de Canarias, Spain), Ignasi Ribas, Enrique Herrero Casas (Institut de Ciències de l’Espai, Spain), Ansgar Reiners, Mathias Zechmeister, Stefan Dreizler, Lev Tal-Or, Sandra Jeffers (University of Goettingen, Germany), Yiannis Tsapras (Astronomisches Rechen-Institut, University of Heidelberg, Germany), Rachel Street (LCOGT.net), James Jenkins, Zaira Modroño Berdiñas (Universidad de Chile, Chile), Aviv Ofir (Weizmann Institute, Israel), Julien Morin (Université de Montpellier and CNRS, France), Gavin Coleman (University of Bern, Switzerland).

[2] The facilities used during the Red Dots campaign are: HARPS/ESO in Chile (Spectroscopy/Doppler measurements and more); and an extended network of small telescopes for photometric monitoring including: Las Cumbres Global Observatory Telescope network; SpaceObs ASH2 in Chile; Observatorio de Sierra Nevada, in Spain; and Observatori Astronomic del Montsec, Spain. In addition to new data, the team will make extensive use of public observations of all three stars from the ESO archives (HARPS and UVES/VLT) and the ASAS photometric survey.

[3] The outreach campaign is coordinated by members of the science team with support from the outreach departments of ESO, Queen Mary University of London, Instituto de Astrofisica de Andalucia/CSIC, Universidad de Chile and University of Goettingen.

Courtesy of European Southern Observatory