Cool Companions on Ultrawide Orbits

File:Coconuts-2b unwise.png

The COol Companions ON Ultrawide orbiTS (COCONUTS) program is a large-scale survey for wide-orbit planetary and substellar companions considered the first survey of this type of celestial bodies.{{Cite journal |last1=Zhang |first1=Z. |last2=Liu |first2=M. |last3=Magnier |first3=E. |date=2020-01-01 |title=COCONUTS: COol Companions ON Ultrawide orbiTS |url=https://ui.adsabs.harvard.edu/abs/2020AAS...23514806Z |volume=235 |pages=148.06 |journal= American Astronomical Society Meeting Abstracts #235|bibcode=2020AAS...23514806Z |access-date=2022-04-02 |archive-date=2022-04-02 |archive-url=https://web.archive.org/web/20220402162302/https://ui.adsabs.harvard.edu/abs/2020AAS...23514806Z |url-status=live }} In 2021, the team announced COCONUTS-2b, the closest exoplanet directly imaged ever.{{Cite web |last=Siegel |first=Ethan |title=Astronomers Go Nuts For Closest Exoplanet Directly Imaged Ever: COCONUTS-2b |url=https://www.forbes.com/sites/startswithabang/2021/08/02/astronomers-go-nuts-for-closest-exoplanet-directly-imaged-ever-coconuts-2b/ |access-date=2022-04-02 |website=Forbes |language=en |archive-date=2021-11-22 |archive-url=https://web.archive.org/web/20211122022619/https://www.forbes.com/sites/startswithabang/2021/08/02/astronomers-go-nuts-for-closest-exoplanet-directly-imaged-ever-coconuts-2b/ |url-status=live }} The program is a dedicated large-scale search for wide-orbit giant planets and brown dwarf companions, targeting a sample of 300,000 stars. By using multi-wavelength photometry and multi-epoch astrometry, astronomers are able to assess the candidates' companionship and ultracool nature.{{Cite web |last=Kooser |first=Amanda |title=Massive exoplanet 'Coconuts-2b' could help reveal the secrets of young gas giants |url=https://www.cnet.com/science/meet-coconuts-2b-an-exoplanet-with-six-times-the-mass-of-jupiter/ |access-date=2022-04-02 |website=CNET |language=en |archive-date=2022-04-02 |archive-url=https://web.archive.org/web/20220402162302/https://www.cnet.com/science/meet-coconuts-2b-an-exoplanet-with-six-times-the-mass-of-jupiter/ |url-status=live }}

List of discoveries

class="wikitable"

!Name

!companion class

!mass ({{Jupiter mass|link=true}})

!orbital separation (au)

!host star

!star class

!host star mass ({{Solar mass|link=true}})

!discovery year

!reference

COCONUTS-1B

|brown dwarf

|15.4 or 69.3

|1280

|PSO J058.9855+45.4184

|old white dwarf

|0.548

|2020

|{{Cite journal |last1=Zhang |first1=Zhoujian |last2=Liu |first2=Michael C. |last3=Hermes |first3=J. J. |last4=Magnier |first4=Eugene A. |last5=Marley |first5=Mark S. |last6=Tremblay |first6=Pier-Emmanuel |last7=Tucker |first7=Michael A. |last8=Do |first8=Aaron |last9=Payne |first9=Anna V. |last10=Shappee |first10=Benjamin J. |date=2020-03-01 |title=COol Companions ON Ultrawide orbiTS (COCONUTS). I. A High-gravity T4 Benchmark around an Old White Dwarf and a Re-examination of the Surface-gravity Dependence of the L/T Transition |journal=The Astrophysical Journal |volume=891 |issue=2 |pages=171 |doi=10.3847/1538-4357/ab765c |issn=0004-637X|arxiv=2002.05723 |bibcode=2020ApJ...891..171Z |doi-access=free }}

COCONUTS-2b

|exoplanet

|6.3

|6471

|L 34-26

|young M-dwarf

|0.37

|2021

|{{Cite journal |last1=Zhang |first1=Zhoujian |last2=Liu |first2=Michael C. |last3=Claytor |first3=Zachary R. |last4=Best |first4=William M. J. |last5=Dupuy |first5=Trent J. |last6=Siverd |first6=Robert J. |date=2021-08-01 |title=The Second Discovery from the COCONUTS Program: A Cold Wide-orbit Exoplanet around a Young Field M Dwarf at 10.9 pc |journal=The Astrophysical Journal |volume=916 |issue=2 |pages=L11 |doi=10.3847/2041-8213/ac1123 |bibcode=2021ApJ...916L..11Z |issn=0004-637X|doi-access=free |arxiv=2107.02805 }}

COCONUTS-3B

|brown dwarf

|39

|1891

|UCAC4 374-046899

|young M-dwarf

|0.123

|2022

|{{Cite journal |last1=Zhang |first1=Zhoujian |last2=Liu |first2=Michael C. |last3=Morley |first3=Caroline V. |last4=Magnier |first4=Eugene A. |last5=Tucker |first5=Michael A. |last6=Vanderbosch |first6=Zachary P. |last7=Do |first7=Aaron |last8=Shappee |first8=Benjamin J. |date=2022-08-01 |title=COol Companions ON Ultrawide orbiTS (COCONUTS). III. A Very Red L6 Benchmark Brown Dwarf around a Young M5 Dwarf |journal=The Astrophysical Journal |volume=935 |issue=1 |pages=15 |doi=10.3847/1538-4357/ac7ce9 |bibcode=2022ApJ...935...15Z |issn=0004-637X|doi-access=free |arxiv=2207.02865 }}

References

Category:Exoplanet search projects

Cool Companions on Ultrawide Orbits

List of discoveries

See also

References