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Title: First discovery of an ultra-cool white dwarf benchmark in common proper motion with an M dwarf

Abstract

Ultra-cool white dwarfs are among the oldest stellar remnants in the Universe. Their efficient gravitational settling and low effective temperatures are responsible for the smooth spectra they exhibit. For that reason, it is not possible to derive their radial velocities or to find the chemistry of the progenitors. The best that can be done is to infer such properties from associated sources, which are coeval. The simplest form of such a system is a common proper motion pair where one star is an evolved degenerate and the other a main-sequence star. Herein, we present the discovery of the first of such a system, the M dwarf LHS 6328 and the ultra-cool white dwarf PSO J1801+625, from the Pan-STARRS 1 3π survey and the Gaia Data Release 2. Follow-up spectra were collected covering a usable wavelength range of 3750–24 500 Å. Their spectra show that the white dwarf has an effective temperature of 3550 K and surface gravity of log $g$ = 7.45 ± 0.13 or log $g$ = 7.49 ± 0.13 for a CO or He core, respectively, when compared against synthetic spectra of ultra-cool white dwarf atmosphere models. The system has slightly subsolar metallicity with -0.25 < [Fe/H] < 0.0, and a spatial velocity ofmore » (U, V, W) = (-114.26 ± 0.24, 222.94 ± 0.60, 10.25 ± 0.34) km s-1, the first radial velocity and metallicity measurements of an ultra-cool white dwarf. This makes it the first and only benchmark of its kind to date.« less

Authors:
ORCiD logo [1];  [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [1];  [1];  [5]; ORCiD logo [6]
  1. Liverpool John Moores Univ. (United Kingdom)
  2. Univ. of Edinburgh, Scotland (United Kingdom). The Royal Observatory
  3. Inst. de Astrofísica de Canarias (IAC), La Laguna, Tenerife (Spain); Univ. de La Laguna (ULL), Tenerife (Spain)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  5. Suffolk Univ., Madrid Campus (Spain)
  6. Nanjing Univ., Jiangsu (China)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA); OPTICON; Spanish Ministry of Economy and Competitiveness (MINECO); Science and Technology Facilities Council (STFC); GRANTE-CAN; Spanish Government; National Aeronautic and Space Administration (NASA); National Science Foundation (NSF); Gordon and Betty Moore Foundation
OSTI Identifier:
1614843
Report Number(s):
LA-UR-19-31660
Journal ID: ISSN 0035-8711
Grant/Contract Number:  
89233218CNA000001; AYA2015-69350-C3-2-P (2016-2019); NNX08AR22G; AST-1238877
Resource Type:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 493; Journal Issue: 4; Journal ID: ISSN 0035-8711
Publisher:
Royal Astronomical Society
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; binaries: visual; stars: low-mass; white dwarfs; solar neighbourhood

Citation Formats

Lam, M. C., Hambly, N. C., Lodieu, N., Blouin, Simon, Harvey, E. J., Smith, R. J., Gálvez-Ortiz, M. C., and Zhang, Z. H. First discovery of an ultra-cool white dwarf benchmark in common proper motion with an M dwarf. United States: N. p., 2020. Web. doi:10.1093/mnras/staa584.
Lam, M. C., Hambly, N. C., Lodieu, N., Blouin, Simon, Harvey, E. J., Smith, R. J., Gálvez-Ortiz, M. C., & Zhang, Z. H. First discovery of an ultra-cool white dwarf benchmark in common proper motion with an M dwarf. United States. doi:https://doi.org/10.1093/mnras/staa584
Lam, M. C., Hambly, N. C., Lodieu, N., Blouin, Simon, Harvey, E. J., Smith, R. J., Gálvez-Ortiz, M. C., and Zhang, Z. H. Thu . "First discovery of an ultra-cool white dwarf benchmark in common proper motion with an M dwarf". United States. doi:https://doi.org/10.1093/mnras/staa584. https://www.osti.gov/servlets/purl/1614843.
@article{osti_1614843,
title = {First discovery of an ultra-cool white dwarf benchmark in common proper motion with an M dwarf},
author = {Lam, M. C. and Hambly, N. C. and Lodieu, N. and Blouin, Simon and Harvey, E. J. and Smith, R. J. and Gálvez-Ortiz, M. C. and Zhang, Z. H.},
abstractNote = {Ultra-cool white dwarfs are among the oldest stellar remnants in the Universe. Their efficient gravitational settling and low effective temperatures are responsible for the smooth spectra they exhibit. For that reason, it is not possible to derive their radial velocities or to find the chemistry of the progenitors. The best that can be done is to infer such properties from associated sources, which are coeval. The simplest form of such a system is a common proper motion pair where one star is an evolved degenerate and the other a main-sequence star. Herein, we present the discovery of the first of such a system, the M dwarf LHS 6328 and the ultra-cool white dwarf PSO J1801+625, from the Pan-STARRS 1 3π survey and the Gaia Data Release 2. Follow-up spectra were collected covering a usable wavelength range of 3750–24 500 Å. Their spectra show that the white dwarf has an effective temperature of 3550 K and surface gravity of log $g$ = 7.45 ± 0.13 or log $g$ = 7.49 ± 0.13 for a CO or He core, respectively, when compared against synthetic spectra of ultra-cool white dwarf atmosphere models. The system has slightly subsolar metallicity with -0.25 < [Fe/H] < 0.0, and a spatial velocity of (U, V, W) = (-114.26 ± 0.24, 222.94 ± 0.60, 10.25 ± 0.34) km s-1, the first radial velocity and metallicity measurements of an ultra-cool white dwarf. This makes it the first and only benchmark of its kind to date.},
doi = {10.1093/mnras/staa584},
journal = {Monthly Notices of the Royal Astronomical Society},
number = 4,
volume = 493,
place = {United States},
year = {2020},
month = {2}
}

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Works referenced in this record:

New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
journal, April 2015


Gaia Data Release 2: First stellar parameters from Apsis
journal, August 2018


A New Generation of Cool White Dwarf Atmosphere Models. I. Theoretical Framework and Applications to DZ Stars
journal, August 2018


Models of very-low-mass stars, brown dwarfs and exoplanets
journal, June 2012

  • Allard, F.; Homeier, D.; Freytag, B.
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 370, Issue 1968
  • DOI: 10.1098/rsta.2011.0269

The origin of subdwarf B stars – I. The formation channels
journal, October 2002


Formation of Extremely Low-mass White Dwarfs in Double Degenerates
journal, January 2019


Photospheric properties and fundamental parameters of M dwarfs
journal, February 2018


Gaia Data Release 2 : Summary of the contents and survey properties
journal, August 2018


Transiting Exoplanet Survey Satellite
journal, October 2014

  • Ricker, George R.; Winn, Joshua N.; Vanderspek, Roland
  • Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 1, Issue 1
  • DOI: 10.1117/1.JATIS.1.1.014003

The 25 parsec local white dwarf population
journal, June 2016

  • Holberg, J. B.; Oswalt, T. D.; Sion, E. M.
  • Monthly Notices of the Royal Astronomical Society, Vol. 462, Issue 3
  • DOI: 10.1093/mnras/stw1357

M-subdwarf Research. I. Identification, Modified Classification System, and Sample Construction
journal, February 2019

  • Zhang, Shuo; Luo, A-Li; Comte, Georges
  • The Astrophysical Journal Supplement Series, Vol. 240, Issue 2
  • DOI: 10.3847/1538-4365/aafb32

A white dwarf with an oxygen atmosphere
journal, March 2016


Disk and Halo Wide Binaries from the Revised Luyten Catalog: Probes of Star Formation and MACHO Dark Matter
journal, January 2004

  • Chaname, Julio; Gould, Andrew
  • The Astrophysical Journal, Vol. 601, Issue 1
  • DOI: 10.1086/380442

White Dwarfs in NGC 6791: Avoiding the Helium Flash
journal, December 2005

  • Hansen, Brad M. S.
  • The Astrophysical Journal, Vol. 635, Issue 1
  • DOI: 10.1086/496951

The Zwicky Transient Facility: System Overview, Performance, and First Results
journal, December 2018

  • Bellm, Eric C.; Kulkarni, Shrinivas R.; Graham, Matthew J.
  • Publications of the Astronomical Society of the Pacific, Vol. 131, Issue 995
  • DOI: 10.1088/1538-3873/aaecbe

High‐Resolution Infrared Spectroscopy of the Old Open Cluster NGC 6791
journal, July 2006

  • Origlia, Livia; Valenti, Elena; Rich, R. Michael
  • The Astrophysical Journal, Vol. 646, Issue 1
  • DOI: 10.1086/504829

Pressure Distortion of the H 2 –He Collision-induced Absorption at the Photosphere of Cool White Dwarf Stars
journal, October 2017


On the Measurement of Fundamental Parameters of White Dwarfs in the Gaia Era
journal, May 2019


parsec : stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
journal, October 2012


High-temperature (1000–7000 K) collision-induced absorption of H2 pairs computed from the first principles, with application to cool and dense stellar atmospheres
journal, February 2001

  • Borysow, Aleksandra; Jørgensen, Uffe G.; Fu, Yi
  • Journal of Quantitative Spectroscopy and Radiative Transfer, Vol. 68, Issue 3
  • DOI: 10.1016/S0022-4073(00)00023-6

Ultracool white dwarfs and the age of the Galactic disc★
journal, April 2015

  • Gianninas, A.; Curd, B.; Thorstensen, John R.
  • Monthly Notices of the Royal Astronomical Society, Vol. 449, Issue 4
  • DOI: 10.1093/mnras/stv545

Stellar Evolution in NGC 6791: Mass Loss on the Red Giant Branch and the Formation of Low‐Mass White Dwarfs
journal, December 2007

  • Kalirai, Jasonjot S.; Bergeron, P.; Hansen, Brad M. S.
  • The Astrophysical Journal, Vol. 671, Issue 1
  • DOI: 10.1086/521922

The formation of permanent soft binaries in dispersing clusters: Permanent soft binaries in dispersing clusters
journal, June 2011


Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main-Sequence Stars
journal, September 2013

  • Pecaut, Mark J.; Mamajek, Eric E.
  • The Astrophysical Journal Supplement Series, Vol. 208, Issue 1
  • DOI: 10.1088/0067-0049/208/1/9

The origin of subdwarf B stars - II
journal, May 2003


The star formation history of the solar neighbourhood from the white dwarf luminosity function
journal, July 2013

  • Rowell, N.
  • Monthly Notices of the Royal Astronomical Society, Vol. 434, Issue 2
  • DOI: 10.1093/mnras/stt1110

White Dwarf Cosmochronology in the Solar Neighborhood
journal, July 2014


The Luminosities of the Coldest Brown Dwarfs
journal, November 2014

  • Tinney, C. G.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy
  • The Astrophysical Journal, Vol. 796, Issue 1
  • DOI: 10.1088/0004-637X/796/1/39

Found: The Missing Blue Opacity in Atmosphere Models of Cool Hydrogen White Dwarfs
journal, October 2006

  • Kowalski, P. M.; Saumon, D.
  • The Astrophysical Journal, Vol. 651, Issue 2
  • DOI: 10.1086/509723

The Potential of White Dwarf Cosmochronology
journal, April 2001

  • Fontaine, G.; Brassard, P.; Bergeron, P.
  • Publications of the Astronomical Society of the Pacific, Vol. 113, Issue 782
  • DOI: 10.1086/319535

The Liverpool Telescope: performance and first results
conference, September 2004

  • Steele, Iain A.; Smith, Robert J.; Rees, Paul C.
  • SPIE Astronomical Telescopes + Instrumentation, SPIE Proceedings
  • DOI: 10.1117/12.551456

White Dwarfs in Common Proper Motion Binary Systems: Mass Distribution and Kinematics
journal, January 2001

  • Silvestri, Nicole M.; Oswalt, Terry D.; Wood, Matt A.
  • The Astronomical Journal, Vol. 121, Issue 1
  • DOI: 10.1086/318005

A new ultracool white dwarf discovered in the SuperCOSMOS Sky Survey
journal, March 2008


Low-Mass Dwarf Template Spectra from the Sloan Digital Sky Survey
journal, January 2007

  • Bochanski, John J.; West, Andrew A.; Hawley, Suzanne L.
  • The Astronomical Journal, Vol. 133, Issue 2
  • DOI: 10.1086/510240

The end of the Macho era, Revisited: new Limits on Macho Masses from halo wide Binaries
journal, July 2014


Constraints on the Initial-Final mass Relation from wide Double White Dwarfs
journal, December 2015

  • Andrews, Jeff J.; Agüeros, Marcel A.; Gianninas, A.
  • The Astrophysical Journal, Vol. 815, Issue 1
  • DOI: 10.1088/0004-637X/815/1/63

The Iraf Data Reduction And Analysis System
conference, October 1986


The initial-final mass relationship from white dwarfs in common proper motion pairs
journal, November 2007


Diffusion and the occurrence of hydrogen-shell flashes in helium white dwarf stars
journal, May 2001


Revised Metallicity Classes for Low‐Mass Stars: Dwarfs (dM), Subdwarfs (sdM), Extreme Subdwarfs (esdM), and Ultrasubdwarfs (usdM)
journal, November 2007

  • Lepine, Sebastien; Rich, R. Michael; Shara, Michael M.
  • The Astrophysical Journal, Vol. 669, Issue 2
  • DOI: 10.1086/521614

The Future Is Now: The Formation of Single Low‐Mass White Dwarfs in the Solar Neighborhood
journal, December 2007

  • Kilic, Mukremin; Stanek, K. Z.; Pinsonneault, M. H.
  • The Astrophysical Journal, Vol. 671, Issue 1
  • DOI: 10.1086/522228

Binary frequency of planet-host stars at wide separations: A new brown dwarf companion to a planet-host star⋆⋆⋆⋆⋆⋆⋆⋆⋆⋆
journal, September 2014


The Initial-Final mass Relation Among White Dwarfs in wide Binaries
journal, February 2012


Radii of 88 M Subdwarfs and Updated Radius Relations for Low-metallicity M-dwarf Stars
journal, January 2019

  • Kesseli, Aurora Y.; Davy Kirkpatrick, J.; Fajardo-Acosta, Sergio B.
  • The Astronomical Journal, Vol. 157, Issue 2
  • DOI: 10.3847/1538-3881/aae982

EMIR at the GTC: results on the commissioning at the telescope
conference, August 2016

  • Garzón, F.; Castro, N.; Insausti, M.
  • SPIE Astronomical Telescopes + Instrumentation, SPIE Proceedings
  • DOI: 10.1117/12.2232885

A New Generation of Cool White Dwarf Atmosphere Models. II. A DZ Star with Collision-induced Absorption
journal, November 2018


Precise Ages of Field Stars from White Dwarf Companions
journal, December 2018

  • Fouesneau, Morgan; Rix, Hans-Walter; von Hippel, Ted
  • The Astrophysical Journal, Vol. 870, Issue 1
  • DOI: 10.3847/1538-4357/aaee74

The Two Micron All Sky Survey (2MASS)
journal, February 2006

  • Skrutskie, M. F.; Cutri, R. M.; Stiening, R.
  • The Astronomical Journal, Vol. 131, Issue 2
  • DOI: 10.1086/498708

Quantitative spectral analysis of the sdB star HD 188112: A helium-core white dwarf progenitor
journal, January 2016


A strip search for new very wide halo binaries: A strip search for new very wide halo binaries
journal, December 2009


The brightest pure-H ultracool white dwarf
journal, October 2012


The Zwicky Transient Facility: Science Objectives
journal, May 2019

  • Graham, Matthew J.; Kulkarni, S. R.; Bellm, Eric C.
  • Publications of the Astronomical Society of the Pacific, Vol. 131, Issue 1001
  • DOI: 10.1088/1538-3873/ab006c

M-Subdwarfs: Spectroscopic Classification and the Metallicity Scale
journal, February 1997

  • Gizis, John E.
  • The Astronomical Journal, Vol. 113
  • DOI: 10.1086/118302

The Palomar/MSU Nearby-Star Spectroscopic Survey. I. The Northern M Dwarfs -Bandstrengths and Kinematics
journal, October 1995

  • Reid, I. Neill; Hawley, Suzanne L.; Gizis, John E.
  • The Astronomical Journal, Vol. 110
  • DOI: 10.1086/117655

An inverse method to interpret colour-magnitude diagrams
journal, August 2002


The Brown Dwarf Kinematics Project (Bdkp). iii. Parallaxes for 70 Ultracool Dwarfs
journal, May 2012

  • Faherty, Jacqueline K.; Burgasser, Adam J.; Walter, Frederick M.
  • The Astrophysical Journal, Vol. 752, Issue 1
  • DOI: 10.1088/0004-637X/752/1/56

The Gaia mission
journal, November 2016


Ages of White Dwarf–Red Subdwarf Systems
journal, February 2006

  • Monteiro, Hektor; Jao, Wei‐Chun; Henry, Todd
  • The Astrophysical Journal, Vol. 638, Issue 1
  • DOI: 10.1086/498676

SPRAT: Spectrograph for the Rapid Acquisition of Transients
conference, July 2014

  • Piascik, A. S.; Steele, Iain A.; Bates, Stuart D.
  • SPIE Astronomical Telescopes + Instrumentation, SPIE Proceedings
  • DOI: 10.1117/12.2055117

Colors and Kinematics of l Dwarfs from the Sloan Digital sky Survey
journal, March 2010


A new insight into the Galactic potential: A simple secular model for the evolution of binary systems in the solar neighbourhood
journal, March 2017


A Detailed Model Atmosphere Analysis of cool White Dwarfs in the Sloan Digital sky Survey
journal, August 2010

  • Kilic, Mukremin; Leggett, S. K.; Tremblay, P. -E.
  • The Astrophysical Journal Supplement Series, Vol. 190, Issue 1
  • DOI: 10.1088/0067-0049/190/1/77

The white dwarf luminosity functions from the Pan–STARRS 1 3π Steradian Survey
journal, October 2018

  • Lam, Marco C.; Hambly, Nigel C.; Rowell, Nicholas
  • Monthly Notices of the Royal Astronomical Society, Vol. 482, Issue 1
  • DOI: 10.1093/mnras/sty2710

The direct detection of the irradiated brown dwarf in the white dwarf–brown dwarf binary SDSS J141126.20+200911.1
journal, September 2018

  • Casewell, S. L.; Littlefair, S. P.; Parsons, S. G.
  • Monthly Notices of the Royal Astronomical Society, Vol. 481, Issue 4
  • DOI: 10.1093/mnras/sty2599

The Metallicity of the Old Open Cluster NGC 6791
journal, May 2006

  • Gratton, Raffaele; Bragaglia, Angela; Carretta, Eugenio
  • The Astrophysical Journal, Vol. 642, Issue 1
  • DOI: 10.1086/500729

The Zwicky Transient Facility: Surveys and Scheduler
journal, April 2019

  • Bellm, Eric C.; Kulkarni, Shrinivas R.; Barlow, Tom
  • Publications of the Astronomical Society of the Pacific, Vol. 131, Issue 1000
  • DOI: 10.1088/1538-3873/ab0c2a

Period04 User Guide
journal, January 2004


Updated Colors for Cool Stars in the Sloan Digital Sky Survey
journal, July 2005

  • West, Andrew A.; Walkowicz, Lucianne M.; Hawley, Suzanne L.
  • Publications of the Astronomical Society of the Pacific, Vol. 117, Issue 833
  • DOI: 10.1086/431368

Wide Binary Systems and the Nature of High-Velocity White Dwarfs
journal, August 2002

  • Silvestri, Nicole M.; Oswalt, Terry D.; Hawley, Suzanne L.
  • The Astronomical Journal, Vol. 124, Issue 2
  • DOI: 10.1086/341382

Binary Evolution in Stellar Dynamics
journal, December 1975


The effective temperature scale of M dwarfs
journal, July 2013


11-12 Gyr old white dwarfs 30 pc away: 11-12 Gyr old WDs
journal, May 2012

  • Kilic, Mukremin; Thorstensen, John R.; Kowalski, P. M.
  • Monthly Notices of the Royal Astronomical Society: Letters, Vol. 423, Issue 1
  • DOI: 10.1111/j.1745-3933.2012.01271.x

An atlas of optical spectra of white-dwarf stars
journal, July 1993

  • Wesemael, F.; Greenstein, J. L.; Liebert, James
  • Publications of the Astronomical Society of the Pacific, Vol. 105
  • DOI: 10.1086/133228

Recovering the star formation rate in the solar neighborhood
journal, September 2006

  • Cignoni, M.; Degl'Innocenti, S.; Prada Moroni, P. G.
  • Astronomy & Astrophysics, Vol. 459, Issue 3
  • DOI: 10.1051/0004-6361:20065645

A New Generation of Cool White Dwarf Atmosphere Models. IV. Revisiting the Spectral Evolution of Cool White Dwarfs
journal, June 2019


On the evolution of a star cluster and its multiple stellar systems following gas dispersal: Star cluster evolution following gas dispersal
journal, May 2010


A Gaia Data Release 2 catalogue of white dwarfs and a comparison with SDSS
journal, November 2018

  • Gentile Fusillo, Nicola Pietro; Tremblay, Pier-Emmanuel; Gänsicke, Boris T.
  • Monthly Notices of the Royal Astronomical Society, Vol. 482, Issue 4
  • DOI: 10.1093/mnras/sty3016

PHYSICAL PROPERTIES OF THE CURRENT CENSUS OF NORTHERN WHITE DWARFS WITHIN 40 pc OF THE SUN
journal, July 2015

  • Limoges, M. -M.; Bergeron, P.; Lépine, S.
  • The Astrophysical Journal Supplement Series, Vol. 219, Issue 2
  • DOI: 10.1088/0067-0049/219/2/19

An Empirical Measurement of the Initial–Final Mass Relation with Gaia White Dwarfs
journal, June 2018

  • El-Badry, Kareem; Rix, Hans-Walter; Weisz, Daniel R.
  • The Astrophysical Journal, Vol. 860, Issue 2
  • DOI: 10.3847/2041-8213/aaca9c

Estimating Distance from Parallaxes. IV. Distances to 1.33 Billion Stars in Gaia Data Release 2
journal, July 2018

  • Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.
  • The Astronomical Journal, Vol. 156, Issue 2
  • DOI: 10.3847/1538-3881/aacb21

The Wide-Field Infrared Survey Explorer (Wise): Mission Description and Initial On-Orbit Performance
journal, November 2010


A Gap in the Lower Main Sequence Revealed by Gaia Data Release 2
journal, July 2018

  • Jao, Wei-Chun; Henry, Todd J.; Gies, Douglas R.
  • The Astrophysical Journal, Vol. 861, Issue 1
  • DOI: 10.3847/2041-8213/aacdf6