You have
stumbled onto Jay Farihi's homepage...
Incriminating information:
I am
currently a research associate at the University of Leicester, digging up
evidence of terrestrial planetary systems at stellar corpses known as white
dwarfs. One might not expect to find the
surviving planetary systems around dead stars, but the universe is full of
surprises. In fact, it is likely we will
learn more about extrasolar terrestrial planets using white dwarfs than via any
other method. This is because cool white
dwarfs have pure hydrogen and helium atmospheres, and those stars with rocky
planetary systems can become polluted by small yet detectable amounts of heavy
elements, such as metals. We can use
this metal pollution to measure the composition of the rocky planetary
material, and even identify water.
I
continue to use the Spitzer Space
Telescope to analyze the rocky debris around white dwarfs; the current
picture is that they externally polluted with heavy elements from tidally
destroyed asteroids. The compositions we
have measured so far are similar to the material found in the inner Solar
System (i.e. like Earth!). Currently, we
estimate at least a few %, and as many as 20-30% of all white dwarfs harbor
terrestrial planetary system remnants.
Relevant publications and press releases can be found below.
I left Gemini Observatory on the big island of Hawaii in
mid-2007, where among other things, I trained for and finished my first Marathon; a huge thanks to all my friends and family
for their support. Kelli deserves special thanks for coming out to see
me finish, helping me celebrate, and most of all for being the woman I adore.
Fond memories:
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 (they are both plentiful and colorful), you can
find my thesis here:
http://whitedwarf.org/theses/farihi.pdf
The
central result of my thesis: a spectral type histogram of low mass companions to white dwarfs. The drop off in companion frequency is
clearly above the minimum mass for hydrogen burning, which corresponds to an
early L dwarf spectral type / temperature at typical white dwarf ages of one to
a few Gyr. Our sensitivity is off the chart. As with solar-type main sequence stars,
intermediate mass stars (the progenitors of white dwarfs) with brown dwarf
companions are rare.
Passions, obsessions, lust for knowledge:
The
ultimate fate of planetary systems
Origin
and evolution of low mass objects
The
local cool white dwarf population
Digging
in the stellar graveyard
I have
been very fortunate to have several of my own space-based research programs on
the Hubble + Spitzer Space Telescopes. Many are posted below with more on the way...
Opinions backed by evidence in order of publication:
1) Mid-Infrared
Observations of van Maanen 2: No Substellar
Companion: astro-ph | ApJL
2) Discovery
of an Ultracool White Dwarf Companion: astro-ph | ApJ
3) A
Possible Brown Dwarf Companion to the White Dwarf GD 1400: astro-ph | AJ
4) Cool
versus Ultracool White Dwarfs: astro-ph | AJ
5) SSSPM
J1549-3544 Is Not a
White Dwarf: astro-ph | ApJL
6) A
Dusty Disk around GD 362, a White Dwarf with a Uniquely High Photospheric Metal
Abundance: astro-ph | ApJL | press
7) Mid-Infrared
Observations of the White Dwarf - Brown Dwarf Binary GD 1400: astro-ph | AJ
8) Low-Luminosity Companions to White Dwarfs (thesis work): astro-ph | ApJS
9) White
Dwarf - Red Dwarf Systems Resolved with the Hubble
Space Telescope. I. First Results: astro-ph | ApJ
10) HST NICMOS Imaging of the Planetary-mass
Companion to the Young Brown Dwarf 2MASSW J1207334-393254: astro-ph | ApJ | press
11) The
Nature of the Close Magnetic White Dwarf - Probable Brown Dwarf Binary
SDSSJ121209.31+013627.7: astro-ph | MNRAS
12) Infrared
Emission from the Dusty Disk Orbiting GD 362, an Externally Polluted White
Dwarf: astro-ph | AJ | press
13) Externally
Polluted White Dwarfs with Dust Disks: 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
15) Spitzer IRAC Observations of White
Dwarfs. I. Warm Dust at Metal-Rich Degenerates: astro-ph | ApJ
16) Near-Infrared
Constraints on the Presence of Warm Dust at Metal-Rich Helium Atmosphere White
Dwarfs: astro-ph | AJ
17) Spitzer IRAC Observations of White
Dwarfs. II. Massive Planetary and Cold Brown Dwarf Companions to Young and Old
Degenerates: astro-ph | ApJ
18) Six
White Dwarfs with Circumstellar Silicates: astro-ph | AJ | press1 | press2
19) Infrared
Signatures of Disrupted Minor Planets at White Dwarfs: astro-ph | ApJ | press | BBC
20) PHL
5038: A Spatially Resolved White Dwarf - Brown Dwarf Binary: astro-ph | A&A
21) X-Ray and Infrared
Observations of Two Externally-Polluted White Dwarfs: astro-ph | ApJ | press
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
23) Deep Imaging Survey of
Young, Nearby Austral Stars. VLT / NACO Near-infrared Lyot-coronographic
Observations: astro-ph | A&A
24) IRTF Observations of White
Dwarfs with Possible Near-Infrared Excess: astro-ph | MNRAS
25) Rocky Planetesimals as the
Origin of Metals in DZ Stars: astro-ph | MNRAS | press | Discovery
26) Does GD 356 Have a
Terrestrial Planetary Companion?: astro-ph | MNRAS
27) Strengthening the Case for
Asteroidal Accretion: Evidence for Subtle and Diverse Disks at White Dwarfs: astro-ph | ApJ
28) A Detailed Model
Atmosphere Analysis of Cool White Dwarfs in the Sloan Digital Sky Survey: astro-ph | ApJS
29) White Dwarf - Red Dwarf
Systems Resolved with the Hubble Space
Telescope. II. Full Snapshot Survey Results: astro-ph | ApJS
30) Possible Signs of Water and
Differentiation in a Rocky Exoplanetary Body: astro-ph | ApJL
31) The Magnetic and Metallic
Degenerate G77-50: astro-ph |
MNRAS
32) Accretion of a
Terrestrial-Like Minor Planet by a White Dwarf: astro-ph | ApJ
33) Evolutionary Constraints on
the Planet-Hosting Subgiant
epsilon Reticulum from
its White Dwarf Companion: astro-ph |
MNRAS
34) An Extremely Luminous
Panchromatic Outburst from the Nucleus of a Distant Galaxy: astro-ph | Science | BBC
35) A Trio of Metal-Rich Dust
and Gas Disks Found Orbiting Candidate White Dwarfs with K-Band Excess: astro-ph | MNRAS
36) Constraints on the
Lifetimes of Disks Resulting from Tidally Destroyed Rocky Planetary Bodies:
astro-ph | ApJ
37) A Second Substellar
Survivor of Post-Main-Sequence Evolution: astro-ph | MNRAS
Meme exchange:
Jay
Farihi
Research
Associate
Department
of Physics & Astronomy
University
of Leicester
Leicester
LE1 7RH
United
Kingdom
Office:
+44 116 252 3577