Year: 2016
Type: article
Abstract: ABSTRACT Proxima Centauri is an M dwarf approximately 15,000 au from the Alpha Centauri binary, comoving and likely in a loosely bound orbit. Dynamic simulations show that this configuration can form from a more tightly bound triple system. As our nearest neighbors, these stars command great interest as potential planet hosts, and the dynamics of the stars govern the formation of any planets within the system. Here we present a scenario for the evolution of Alpha Centauri A and B and Proxima Centauri as a triple system. Based on N-body simulations, we determine that this pathway to formation is plausible, and we quantify the implications for planet formation in the Alpha Centauri binary. We expect that this formation scenario may have truncated the circumstellar disk slightly more than a system that formed in the current configuration, but that it most likely does not prevent terrestrial planet formation. We simulate planet formation in this system and find that, in most scenarios, two or more terrestrial planets can be expected around either Alpha Centauri A or B, orbiting in a region out to approximately 2 au, assuming that planetesimals and planetary embryos are able to form in the system first. Additionally, terrestrial planet formation and stability in Proxima Centauri’s habitable zone are also plausible. However, an absence of planets around these stars may be indicative of highly disruptive stellar dynamics in the past.
Source: The Astrophysical Journal
Authors: R. Worth, S. Sigurdsson
Institution: Pennsylvania State University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: TITLE: SIGNATURES OF LIFE FROM EARTH AND BEYOND IS IN RESPONSE TO CAN #NNH08ZDA002C NASA ASTROBIOLOGY INSTITUTE - CYCLE 5 BASIC AWARD FOR CYCLE FIVE OF NAI TO PENN STATE.1260.51 COOPERATIVE AGREEMENT SPECIAL CONDITION. (OCTOBER 2000) (A) THIS AWARD IS A COOPERATIVE AGREEMENT AS IT IS ANTICIPATED THERE WILL BE SUBSTANTIAL NASA INVOLVEMENT DURING PERFORMANCE OF THE EFFORT. NASA AND THE RECIPIENT MUTUALLY AGREE TO THE FOLLOWING STATEMENT OF ANTICIPATED COOPERATIVE INTERACTIONS WHICH MAY OCCUR DURING THE PERFORMANCE OF THIS EFFORT: NAI CENTRAL IS RESPONSIBLE FOR COORDINATING INSTITUTE ACTIVITIES ADVOCATING THE NEEDS & SCIENTIFIC INTERESTS OF THE MEMBERS OF THIS COOPERATIVE AGREEMENT DISBURSING FUNDS (INCLUDING A STRATEGIC DIRECTOR S DISCRETIONARY FUND FOR HIGH-RISK/HIGH-PAYOFF RESEARCH PROJECTS AND FOR FOSTERING COLLABORATION BETWEEN MEMBERS) SPONSORING THE NAI POSTDOCTORAL FELLOWSHIP PROGRAM COLLECTING AND ARCHIVING INFORMATION ON RESEARCH ACCOMPLISHMENTS & PUBLICATIONS ORGANIZING FOCUS GROUP MEETINGS & WORKSHOPS & EXPEDITING NETWORK CONNECTIVITY WHILE ENGINEERING THE INTERFACES BETWEEN THE SCIENTISTS & THE NETWORK. NAI CENTRAL IS ALSO RESPONSIBLE FOR ORGANIZING GENERAL MEETINGS WORKSHOPS & STRATEGIC RETREATS TO ENGAGE MEMBERS OF THE INSTITUTE IN INTEGRATED RESEARCH. NAI CENTRAL WILL IN ADDITION COORDINATE INSTITUTE-WIDE ACTIVITIES IN EDUCATION & PUBLIC OUTREACH & IN THE TRAINING OF STUDENTS & OTHER YOUNG INVESTIGATORS.AT THE CORE OF ASTROBIOLOGY IS THE CONSTRUCTION OF SCIENTIFIC KNOWLEDGE THAT ENABLES THE RECOGNITION OF SIGNATURES OF LIFE ON EARLY EARTH IN EXTREME ENVIRONMENTS AND IN EXTRATERRESTRIAL SETTINGS. TOGETHER WITH NEW CO-INVESTIGATORS FROM UNIVERSITY OF CALIFORNIA LOS ANGELES AND CALIFORNIA INSTITUTE OF TECHNOLOGY WE PROPOSE TO DEVELOP NOVEL APPROACHES TO DETECTING AND CHARACTERIZING LIFE INVESTIGATE BIOSIGNATURES IN MISSION-RELEVANT ECOSYSTEMS AND ANCIENT ROCKS AND EVALUATE THE POTENTIAL FOR BIOSIGNATURES IN EXTRATERRESTRIAL SETTINGS.(1) DEVELOPING NEW BIOSIGNATURES THE DEVELOPMENT AND TESTING OF POTENTIAL INDICATORS OF LIFE IS ESSENTIAL FOR PROVIDING A CRITICAL SCIENTIFIC BASIS FOR EXPLORATION OF LIFE IN THE COSMOS. OUR EFFORTS WILL FOCUS ON CREATING INNOVATIVE APPROACHES FOR THE ANALYSES OF CELLS AND OTHER ORGANIC MATERIAL FINDING WAYS IN WHICH METAL ABUNDANCES AND ISOTOPE SYSTEMS REFLECT LIFE AND DEVELOPING CREATIVE APPROACHES FOR USING ENVIRONMENTAL DNA TO STUDY PRESENT AND PAST LIFE.(2) BIOSIGNATURES IN RELEVANT MICROBIAL ECOSYSTEMS PSARC WILL INVESTIGATE MICROBIAL LIFE IN SOME OF EARTH S MOST MISSION-RELEVANT ECOSYSTEMS THE DEAD SEA THE CHESAPEAKE IMPACT STRUCTURE THE METHANE SEEPS OF THE EEL RIVER BASIN AND THE GREENLAND GLACIER ICE.(3) BIOSIGNATURES IN ANCIENT ROCKS THE EARTH S ARCHEAN AND PROTEROZOICEONS OFFER THE BEST OPPORTUNITY OF INVESTIGATING A MICROBIAL WORLD SUCH AS MIGHT BE FOUND ELSEWHERE IN THE COSMOS. THE ANCIENT RECORD ON EARTH PROVIDES ON OPPORTUNITY TO SEE WHAT GEOCHEMICAL SIGNATURES ARE PRODUCED BY MICROBIAL LIFE AND HOW THESE SIGNATURES ARE PRESERVED OVER GEOLOGIC TIME.(4) BIOSIGNATURES IN EXTRATERRESTRIAL SETTING. PSARC WILL INVESTIGATE THE ABUNDANCE OF SULFUR GASES AND ELUCIDATE HOW THESE GASES CAN BE EXPECTED TO EVOLVE WITH TIME ON YOUNG TERRESTRIAL PLANETS. WE WILL CONTINUE STUDIES OF PLANET FORMATION IN THE PRESENCE OF MIGRATION AND MODEL RADIAL TRANSPORT OF VOLATILES IN YOUNG PLANETARY SYSTEMS. FINAL PSARC WILL BE INVOLVED WITH SEARCHES FOR M STAR PLANETARY COMPANIONS AND PLANETS AROUND K-GIANT STARS.(B) THE TERMS ....(C) NASA S ABILITY TO PARTICIPATE ...., G4033973077
OpenAlex ID: W2470338149