Marc Kuchner
NASA Goddard Space Flight Center
Exoplanets and Stellar Astrophysics Laboratory

Code 667
Greenbelt, MD 20771
Marc.Kuchner at
CV and Publication List

I work on theoretical and observational projects related to directly imaging Extrasolar Planetary Systems. This page describes some of my research interests and provides links to other pages useful to my collaborators.

WD Disk Some White Dwarfs appear to host clouds of dust similar to cometary dust in the solar system. Our sun will eventually become a white dwarf; dusty white dwarfs may represent the future of planetary systems like the solar system. Directly imaging planets around white dwarfs may be especially easy, because a white dwarf is smaller than Jupiter!

Powerpoint Press Release Talk on Cometary Dust around a White Dwarf
Powerpoint Talk on WDs I gave at Carnegie DTM 2/06

Coronagraph Image Plane The technique of Coronagraphy increases the dynamic range of a telescope so it can see planets without being swamped by the glare from the stars they orbit. Here is an image of Sirius made with a conventional coronagraph. I am working on a new design concept for a Terrestrial Planet Finder telescope in space: a Coronagraph with a Band-Limited Mask.. The latest version of the band-limited mask is the eighth-order mask.

Another potential way to directly image extrasolar planets is with a groundbased Giant Segmented Mirror Telescope. We may also someday see radio synchrotron emission from extrasolar planets.
Carbon Planet Imagining New Kinds of Planets can help us decide where and how to look for extrasolar planets. Extrasolar planets are not necessarily like the ones in the solar system; they may have completely different chemistries, like Water Planets or Carbon Planets . Life on a carbon planet would be through-the-looking-glass. The processes of burning and metabolism on Earth are oxidation (combining things with oxygen); on a carbon planet, these processes would probably be replaced by reduction (combining things with carbon). Artist Lynette Cook created this image of a Carbon Planet.

No Earths Allowed! General Astrophysics with TPF
What can the Terrestrial Planet Finder missions do besides look for extrasolar Earths? They can study Jupiters, Neptunes, and debris disks. And with an extra instrument or two, they can potentially search for high-z supernovae, map protoplanetary disks in molecular hydrogen, and image AGNs, AGBs and distant galaxies at a resolution of 1 milliarcsecond.

General Astrophysics with TPF Workshop
General Astrophysics and Comparative Planetology White Paper

Vega Disk Model Our Sun sports a handsome disk of zodiacal dust, full of structures due to the dynamical effects of planets. Here is an explanation, with illustrations, of how planets on low-eccentricity orbits make rings and wakes in an optically thin circumstellar dust cloud. Zodiacal dust around other stars is called Exozodiacal Dust.
Debris Disk Animation

This animation shows what a few-jupiter-mass planet on an eccentric orbit (e=0.6) can do to a dust cloud. The solar system doesn't have any such planets, but extrasolar planetary systems often do. Millimeter maps of the debris around Vega show two blobs of emission at different distances from the star which may be the same phenomenon. However, this disk and other Debris Disks may be much more complicated than the solar dust cloud.

Animation of Dust Orbiting Vega
Press Release on Millimeter Maps of Vega
Powerpoint Talk on Resonant Signatures in Debris Disks

floating teacups Finding faint objects such as planets and dust disks near bright, nearby stars takes high resolution and high dynamic range. Optical and infrared Interferometry can provide high resolution and high dynamic range by combining the light from two or more widely-spaced telescopes. Interferometers like the Palomar Testbed Interferometer are already capable of resolutions of almost 1 milliarcsecond, enough to resolve an object the size of a nickel in New York---from a mountaintop in California. The Keck Interferometer will have almost as high resolution as PTI, and it will harness the collecting area of the two 10-meter Keck telescopes. This new tool can probe the central 1 AU of debris disks, and disks around Young Stellar Objects.

Powerpoint Talk on Keck Interferometer Nuller Shared Risk Science Program

Image of Dusty Rings made with ZODIPIC Here is the ZODIPIC package, an IDL program for synthesizing images of exozodiacal clouds. It also has enough tweakable parameters to serve as a general-purpose modeling tool for optically-thin disks. To use it, you may download zodipic to your idl directory. Save the file as "zodipic.2.1.tar". Then type

tar xvf zodipic.2.1.tar

to unpack the files (total about 57K). The README.zodipic file describes how to run the code. The picture above was made by running zodipic twice:

zodipic, fnu1, 1, 0.5, inclination=60, positionangle=-10, ring=1, blob=1, pixnum=256, /noiterate, /nofan
zodipic, fnu2, 1, 0.5, inclination=60, positionangle=-10, ring=1, blob=1, pixnum=256, /noiterate, /nofan, radring=0.72, earthlong=100

NEW! Zodipic Version 2.1.
Includes dust with real optical constants, user-specified dust maps, and more!
See also

Kuchner, M. J., & Serabyn, E. 2001, submitted to ApJ
Powerpoint Talk on ZODIPIC

Telescope at Mt. Palomar On some cloudy nights, I like to write Observing Manuals like this guide to the Palomar 60" CCD Camera.

And here are some of my other Powerpoint Talks

Dude With Diploma I am lucky to work with some talented Graduate Students and Postdocs:

Chris Stark Graduate Student, U. Maryland Physics Dept. Now a NASA Postdoctoral Program fellow at Goddard Space Flight Center
Daniel Jontof-Hutter Grad. Student, U.M.D. Astronomy
Justin Crepp Graduate Student, U. Florida, Astronomy Dept. Now an assistant professor at the University of Natre Dame.
Erika Nesvold Graduate Student, University of Maryland Baltimore County Physics Dept.
Aki Roberge NPP Postdoctoral Fellow, GSFC. Now a staff scientist at GSFC.
Ruslan Belikov NPP Postdoctoral Fellow, GSFC. Now a staff scientist at NASA Ames.
Hannah Jang-Condell Michelson Postdoctoral Fellow, GSFC/UMD. Now an assistant professor at the University of Wyoming.
John Wisniewski NPP Postdoctoral Fellow, GSFC. Now an assistant professor at the University of Oklahoma.
John Debes NPP postdoctoral fellow, GSFC. Now a staff scientist at STScI.
Thayne Currie NPP postdoctoral fellow, GSFC. Now a postdoctoral fellow at the University of Toronto.
Margaret Pan NPP postdoctoral fellow, GSFC.

Artist's Concept of Planetary System If you are in the DC area, please stop by and give a talk at the Goddard Exoplanets Club. We meet on Wednesdays at 11am at Goddard in Building 34, Room E215.
Here are some possibly useful Astronomy Links:

Q&A With Astronomy Magazine
Princeton Astronomy Webmail
Aspen Conference on Planet Formation and Detection February 6-12, 2005
JPL Docushare
Princeton Seminar Series on Extrasolar Planets and Astrobiology
Paw Points
Database of Observational Mishaps
Statistical Consulting Center for Astronomy
Cosmic Dust
Caltech Ge 167
CfA Star and Planet Formation Journal Club
Astronomy Meetings
CDS 270
Exploring Neighboring Planetary Systems
Harvard Extrasolar Planets Site
California/Carnegie Extrasolar Planets Site
Astrophysics Data System
Caltech Astronomy Department
Astronomical Pronunciation Guide
Simbad astronomical database
Skyview virtual telescope
RECONS Research Consortium on Nearby Stars
astro-ph Preprint Server
Division of Dynamical Astronomy
ExNPS Exploring Neighboring Planetary Systems site at JPL
Protostars and Planets IV
Astrobiology Office at NASA Ames Research Center.
NED NASA/IPAC Extragalactic Database.
The Large Binocular Telescope
The Submillimeter Array
Atacama Large Millimeter Array
Harvard College Observatory Tennis Club
Did you know that Queen guitarist Brian May used to study zodiacal dust?

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