You have stumbled
onto Jay Farihi's homepage...
Incriminating information:
I am a Professor in the Astrophysics
group at University College London, and a former (2012-2017) Ernest Rutherford
Fellow. Prior to UCL, I was a Senior
Fellow at the Institute of Astronomy in Cambridge, and held postdoctoral
positions at the University of Leicester and Gemini Observatory North. My doctoral research was carried out at the
University of California, Los Angeles.
Our research group:
I am fortunate to work with a
diverse and talented group of PhD and master's students, who are shown below
and working on a variety of problems related to our mutual scientific
interests. Our group is particularly focused
on telescope data, much of it taken ourselves in dedicated programs awarded by
telescopes such a Spitzer, Hubble, and James Webb in space, as
well as facilities like the VLT and Keck on the ground. However, we increasingly make use of large
datasets available to the astronomical community, including the TESS and
Gaia missions, which offer unprecedented information, especially for the
small stellar embers known as white dwarfs.
Our interests include the assembly and fate of planetary systems via
white dwarf pollution and debris disks, the formation and evolution of low-mass
companions to white dwarfs, the local cool white dwarf population, the origin
and manifestation of magnetism in white dwarfs.
And more...
The team:
A primary research activity is
digging up evidence of terrestrial planetary systems around white dwarf
stars. One might not expect to find the
surviving planetary systems around dead stars, but the universe is full of
surprises. Moreover, white dwarf
planetary systems defy the notion of the silent graveyard, and instead a
significant fraction show one or more signs of dynamical reanimation. These include variations in the infrared
consistent with ongoing dust production within their debris disks, transiting
clouds of debris and disintegrating planetesimals, and otherwise-pristine
stellar surfaces that are `polluted' with this planetary material. Amazingly, the bulk chemistry of entire
planetesimals or planetary fragments are revealed by the polluted stellar
atmospheres of white dwarf stars. This includes compelling evidence
for Earth-like chemistry, planetary differentiation, and water. In fact,
it is likely we will learn more about extrasolar planetary surfaces and
interiors using white dwarfs than via any other method. Over the years, our group has expanded our
research interests, and we currently study white dwarfs with low-mass stellar
and substellar companions, dwarf carbon stars which have been likely polluted
by giant companions that have since evolved into white dwarfs, and last but not
least magnetic white dwarfs. Relevant
publications and press releases can be found below.
The early years:
As a graduate student, I worked with
Eric Becklin & Ben Zuckerman searching for low
mass stellar and substellar companions to nearby white dwarfs. The bulk of my
thesis is published in an ApJ Supplement Series paper. If you want all the
gory details, you can find my thesis here:
http://whitedwarf.org/theses/farihi.pdf
Inverted chronology of publications:
112) Subtle
and Spectacular: Diverse White Dwarf Debris Disks Revealed by JWST: astro-ph | ApJL
111) Constraints
on Remnant Planetary Systems as a Function of Main-Sequence Mass with HST COS: astro-ph | ApJ
110) Novel
Constraints on Companions to the Helix Nebula Central Star: astro-ph | MNRAS
109) The Frequency
of Transiting Planetary Systems around Polluted White Dwarfs: astro-ph | MNRAS
108) Atmospheric
Heating and Magnetism Driven by 22Ne Distillation in Isolated White Dwarfs:
astro-ph | A&A
106) Metal Accretion
Scars May Be Common on Magnetic Polluted White Dwarfs: astro-ph | A&A
105) Measuring
White Dwarf Variability from Sparsely Sampled Gaia DR3 Multi-Epoch Photometry: astro-ph | ApJ
104) White
Dwarf Pollution: One Star or Two?: astro-ph | MNRAS
103) Missing
Metals in DQ Stars: a Compelling Clue to their Origin: astro-ph | MNRAS
102) Discovery
of Magnetically Guided Metal Accretion onto a Polluted White Dwarf: astro-ph | ApJL | press
101) The
Morphology of Asteroidal Dust Around White Dwarf Stars: Optical and
Near-infrared Pulsations in G29-38: astro-ph | ApJ
100) A Nearby
Polluted White Dwarf with a 6.2 h Spin Period: astro-ph | MNRAS
99) The First
White Dwarf Debris Disk Observed by JWST: astro-ph | MNRAS
98) WD 0141-675:
A Case Study on How to Follow-up Astrometric Planet Candidates around White Dwarfs:
astro-ph | MNRAS
97) Planetesimals
at DZ Stars I: Chondritic Compositions and a Massive Accretion Event: astro-ph | MNRAS
96) An HST
COS Ultraviolet Spectroscopic Survey of 311 DA White Dwarfs. I. Fundamental Parameters
and Comparative Studies: astro-ph | MNRAS
95) Discovery
of Dipolar Chromospheres in Two White Dwarfs: astro-ph | MNRAS
94) Measurement of Stellar and Substellar Winds Using White Dwarf Hosts: astro-ph | MNRAS
93) Two Substellar
Survivor Candidates; One Found and One Missing:
astro-ph | MNRAS
92) Gaia
White Dwarfs within 40 pc - III. Spectroscopic Observations of New Candidates
in the Southern Hemisphere: astro-ph | MNRAS
91) The
Gliese 86 Binary System: A Warm Jupiter Formed in a Disk Truncated at 2 AU: astro-ph | AJ
90)
Relentless and Complex Transits from a Planetesimal Debris Disk: astro-ph | MNRAS | press | BBC
89)
Collisions in a Gas-Rich White Dwarf Planetary Debris Disc: astro-ph | MNRAS
88)
Carbon-Enhanced Stars with Short Orbital and Spin Periods: astro-ph | MNRAS
87) A Test of
the Planet-Star Unipolar Inductor for Magnetic White Dwarfs: astro-ph | MNRAS
86)
Horizontal Spreading of Planetary Debris Accreted by White Dwarfs: astro-ph | MNRAS
85) White
Dwarfs with Planetary Remnants in the Era of Gaia I. Six Emission Line
Systems: astro-ph | MNRAS
84) GD 424, a
Helium Atmosphere White Dwarf with a Large Amount of Trace Hydrogen in the Process
of Digesting a Rocky Planetesimal: astro-ph | MNRAS
83) White Dwarf Pollution by Hydrated Planetary
Remnants: Hydrogen and Metals in WD J204713.76–125908.9: astro-ph | MNRAS
82) Gaia White Dwarfs within 40
pc. I. Spectroscopic Observations of New Candidates: astro-ph | MNRAS
81) The Dust Never Settles:
Collisional Production of Gas and Dust in Evolved Planetary Systems: astro-ph | MNRAS
80) A Word to the WISE:
Confusion Is Unavoidable for WISE-Selected
Infrared Excesses: astro-ph | ApJ
79) Interpretation and Diversity of Exoplanetary Material Orbiting
White Dwarfs: astro-ph | MNRAS
78) A Chandra Study: Are Dwarf Carbon Stars Spun Up and Rejuvenated by Mass Transfer?: astro-ph | ApJ
77) The Unbiased Frequency of Planetary Signatures around Single and Binary White
Dwarfs using Spitzer and Hubble:
astro-ph | MNRAS
76) A Planetesimal Orbiting within the Debris Disc around
a White Dwarf Star: astro-ph | Science
75) Most White Dwarfs with Detectable Dust Discs Show
Infrared Variability: astro-ph | MNRAS
74) Evidence for Bimodal Orbital Separations of White
Dwarf - Red Dwarf Binary Stars: astro-ph | MNRAS
73) Multi-Wavelength Observations of the EUV Variable Metal-Rich White Dwarf
GD 394: astro-ph | MNRAS
72)
Broadening of Ly-alpha by Neutral Helium in DBA White Dwarfs: astro-ph | MNRAS
71) Dust
Production and Depletion in Evolved Planetary Systems: astro-ph | MNRAS
70) Fast
Spectrophotometry of WD 1145+017: astro-ph | MNRAS
69) Infrared
Variability of Two Dusty White Dwarfs: astro-ph | ApJ
68) Dwarf Carbon Stars Are Likely Metal-Poor Binaries and
Unlikely Hosts to Carbon Planets: astro-ph | MNRAS
67) Evidence for Halo Kinematics among Cool Carbon-Rich Dwarfs: astro-ph | MNRAS
66) Evidence for Eccentric, Precessing
Gaseous Debris in the Circumstellar Absorption toward WD 1145+017: astro-ph | ApJL
65) The First
Post-Kepler Brightness Dips of KIC
8462852: astro-ph | ApJL
64) Periodic
Optical Variability and Debris Accretion in White Dwarfs: a Test for a Causal Connection:
astro-ph | MNRAS
63)
Magnetism, X-rays, and Accretion Rates in WD 1145+017 and other Polluted White
Dwarf Systems: astro-ph | MNRAS
62) Magnetospherically-Trapped Dust and a Possible Model for
the Unusual Transits at WD 1145+017: astro-ph | MNRAS
61) Spectroscopic
Evolution of Disintegrating Planetesimals: Minutes to Months Variability in the
Circumstellar Gas Associated with WD 1145+017: astro-ph | ApJ
60) Trace Hydrogen in Helium Atmosphere White Dwarfs as
a Possible Signature of Water Accretion: astro-ph | MNRAS
59) Infrared Observations of White Dwarfs and the
Implications for the Accretion of Dusty Planetary Material: astro-ph | MNRAS
58) A
Circumbinary Debris Disk in a Polluted White Dwarf System: astro-ph | Nature
Astronomy | press
57) Solar
Abundances of Rock Forming Elements, Extreme Oxygen and Hydrogen in a Young
Polluted White Dwarf: astro-ph | MNRAS
56)
Carbon to Oxygen Ratios in Extrasolar Planetesimals: astro-ph | MNRAS
55) Circumstellar Debris and
Pollution at White Dwarf Stars: astro-ph | NewAR | press
54) High-Speed Photometry of the Disintegrating Planetesimals
at WD 1145+017: Evidence for Rapid Dynamical Evolution: astro-ph | ApJ
53) Likely Detection of Water-Rich Asteroid
Debris in a Metal-Polluted White Dwarf: astro-ph | MNRAS
52) The
Frequency and Infrared Brightness of Circumstellar Discs at White Dwarfs: astro-ph | MNRAS
51) Signs of a Faint Disc Population at Polluted
White Dwarfs: astro-ph | MNRAS
50) ALMA and Herschel
Observations of the Prototype Dusty and Polluted White Dwarf G29-38: astro-ph | MNRAS
49) Heavy Metals in a Light White Dwarf:
Abundances of the Metal-Rich, Extremely Low-Mass GALEX J1717+6757: astro-ph | MNRAS
48) The
Puzzling Source IGR J17361-4441 in NGC 6388: A Possible Planetary Tidal Disruption Event: astro-ph | MNRAS
47) The Frequency of
Planetary Debris at Young White Dwarfs: astro-ph | A&A
46) Stochastic Accretion
of Planetesimals onto White Dwarfs. Constraints on the Mass Distribution of Accreted
Material from Atmospheric Pollution: astro-ph | MNRAS
45) Evidence for
Water in the Rocky Debris of a Disrupted Extrasolar Minor Planet: astro-ph | Science | press | BBC | Hubble | Nature
44) Evidence of Rocky Planetesimals Orbiting Two Hyades Stars: astro-ph | MNRAS | press | BBC
43) Orbital and Evolutionary Constraints on the Planet Hosting
Binary GJ 86 from the Hubble Space
Telescope: astro-ph | MNRAS
42) The WIRED Survey III: An Infrared Excess around the
Eclipsing Post-Common Envelope Binary SDSS J030308.35+005443.7: astro-ph | ApJ
41) Precision Astrometry of the Exoplanet Host Candidate GD 66: astro-ph | MNRAS
40) The Chemical Diversity of Exoterrestrial
Planetary Debris Around White Dwarfs: astro-ph | MNRAS | press
39) Scars of Intense Accretion Episodes at Metal-Rich White Dwarfs: astro-ph | MNRAS
38) Gaseous Material Orbiting the Polluted White Dwarf HE 1349-2305: astro-ph | ApJ
37) The Origin of Circumstellar Features in the Spectra of Hot
DA White Dwarfs: astro-ph | MNRAS
36) Constraints on the
Lifetimes of Disks Resulting from Tidally Destroyed Rocky Planetary Bodies: astro-ph | ApJ
35) A Trio of Metal-Rich
Dust and Gas Disks Found Orbiting Candidate White Dwarfs with K-Band Excess: astro-ph | MNRAS
34) An Extremely Luminous
Panchromatic Outburst from the Nucleus of a Distant Galaxy: astro-ph | Science | BBC
33) Evolutionary
Constraints on the Planet-Hosting Subgiant epsilon Reticulum from its White Dwarf
Companion: astro-ph | MNRAS
32) Accretion of a
Terrestrial-Like Minor Planet by a White Dwarf: astro-ph | ApJ
31) The Magnetic and
Metallic Degenerate G77-50: astro-ph | MNRAS
30) Possible Signs of
Water and Differentiation in a Rocky Exoplanetary Body: astro-ph | ApJL
29) White Dwarf - Red Dwarf
Systems Resolved with the Hubble Space
Telescope. II. Full Snapshot Survey Results: astro-ph | ApJS
28) A Detailed Model
Atmosphere Analysis of Cool White Dwarfs in the Sloan Digital Sky Survey: astro-ph | ApJS
27) Strengthening the
Case for Asteroidal Accretion: Evidence for Subtle and Diverse Disks at White
Dwarfs: astro-ph | ApJ
26) Does GD 356 Have a
Terrestrial Planetary Companion?: astro-ph | MNRAS
25) Rocky Planetesimals
as the Origin of Metals in DZ Stars: astro-ph | MNRAS | press
24) IRTF Observations of
White Dwarfs with Possible Near-Infrared Excess: astro-ph | MNRAS
23) Deep Imaging Survey
of Young, Nearby Austral Stars. VLT / NACO Near-infrared Lyot-Coronographic
Observations: astro-ph | A&A
22) A Glimpse of the End
of the Dark Ages: The Gamma-Ray Burst of 23 April 2009 at Redshift 8.3: astro-ph | Nature | BBC
21) X-Ray and Infrared
Observations of Two Externally-Polluted White Dwarfs: astro-ph | ApJ | press
20)
PHL 5038: A Spatially Resolved White Dwarf - Brown Dwarf Binary: astro-ph | A&A
19)
Infrared Signatures of Disrupted Minor Planets at White Dwarfs: astro-ph | ApJ | press | BBC
18)
Six White Dwarfs with Circumstellar Silicates: astro-ph | AJ | press
17) Spitzer IRAC Observations of White
Dwarfs. II. Massive Planetary and Cold Brown Dwarf Companions to Young and Old
Degenerates: astro-ph | ApJ
16)
Near-Infrared Constraints on the Presence of Warm Dust at Metal-Rich Helium
Atmosphere White Dwarfs: astro-ph | AJ
15) Spitzer IRAC Observations of White
Dwarfs. I. Warm Dust at Metal-Rich Degenerates: astro-ph | ApJ
14) A
Near-Infrared Spectroscopic Study of the Accreting Magnetic White Dwarf SDSS
J121209.31+013627.7 and Its Substellar Companion: astro-ph | ApJ | press
13)
Externally Polluted White Dwarfs with Dust Disks: astro-ph | ApJ
12)
Infrared Emission from the Dusty Disk Orbiting GD 362, an Externally Polluted
White Dwarf: astro-ph | AJ | press
11)
The Nature of the Close Magnetic White Dwarf - Probable Brown Dwarf Binary
SDSSJ121209.31+013627.7: astro-ph | MNRAS
10) HST NICMOS Imaging of the Planetary-mass
Companion to the Young Brown Dwarf 2MASSW J1207334-393254: astro-ph | ApJ | press
9)
White Dwarf - Red Dwarf Systems Resolved with the Hubble Space Telescope. I. First Results: astro-ph | ApJ
8) Low-Luminosity Companions to White Dwarfs (thesis work): astro-ph | ApJS
7) Mid-Infrared Observations of the White Dwarf - Brown Dwarf
Binary GD 1400: astro-ph | AJ
6) A
Dusty Disk around GD 362, a White Dwarf with a Uniquely High Photospheric Metal Abundance: astro-ph | ApJL | press
5)
SSSPM J1549-3544 Is Not a
White Dwarf: astro-ph | ApJL
4)
Cool versus Ultracool White Dwarfs: astro-ph | AJ
3) A
Possible Brown Dwarf Companion to the White Dwarf GD 1400: astro-ph | AJ
2)
Discovery of an Ultracool White Dwarf Companion: astro-ph | ApJ
1) Mid-Infrared
Observations of van Maanen 2: No Substellar
Companion: astro-ph | ApJL
Coordinates:
Jay Farihi
Professor
Physics and Astronomy
University College London
London WC1E 6BT
United Kingdom
j dot farihi at ucl dot ac dot uk