Name: Uffe Gråe Jørgensen Title: associate professor (Danish "lektor") Email: email@example.com Fax: +45 3532 5989 Phone: +45 3532 5998 Secretary: +45 3532 5996 The postal address of the institute is: Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark The building was originally donated by the Rockefeller Foundation, and is therefore called the Rockefeller Complex ("Rockefeller Komplekset"). You will get a map of the area with "Rockefeller_Komplekset" marked on the map by clicking here. My office is room 037, at the ground floor of the building to the left after entering the main entrance.
(1) Extrasolar planets (exoplanets) Since 2002 I have been involved
in the search for extrasolar planets by use of the microlensing technique, as
part of the international team PLANET .
Our most recent result is the discovery of the
first Earth-like exoplanet ever seen. Although the planet is far from
identical to the Earth (for one it is estimated to have a surface temperature
of -200 Celcius degrees), it is Earth-like in the sense of
having a mass (5.5 Earth-masses) and an orbit (2.6 AU) much more resembling the
Earth than any
exoplanets ever observed
before, and by being the
only of the known exoplanets which might have formed and eveloved in the same way
as the terrestrial planets in our own solar system (see below).
The printed version of the paper describing the first results of the discovery,
can be forund in Nature, vol.439, p.437-440. If your login allows it, the paper
can be downloaded from
homepage (otherwise use the ads-link above to retrieve a re-print)
together with Nature's comments to the discovery on page 400-401 in the same issue of
the journal. A short press-release
animation made by ESO can be viewed here.
Other recent papers related to the work on microlensing by our team, include 1 , 2 , 3 , 4 , 5 , 6 , 7 .
(2) Late stages of stellar evolution. This has included research about
(1)red giant stars, (e.g., chemical abundances in Galactic halo stars , the formation of poly aromatic hydrocarbon clusters, PAH , and effects of mass loss on stellar evolution),
(2) white dwarfs ,
(3) globular clusters and the age of the universe, (e.g., results , and the method ),
(4) stellar populations in other galaxies (e.g., the Fornax Dwarf galaxy , population synthesis by use of the Ca IR triplet , and the UV radiation in metal-rich galaxies ) and
(5) other aspects of the final stages of evolution of normal stars (e.g., the final evolution of the Sun )
(3) The atmospheres of late-type stars, planets, brown dwarfs, and other
plasmas where molecular absorption plays a role.
Most of the work I have done in the field of modeling and simulations of cool
gasses, is done
with the MARCS stellar atmospheric code. A review of the atmospheric modelling was
given in late
1994 in Astr.Astrophys.Rev..
My major contributions to the development of the atmospheric modelling
(1) effects and compuitations in spherical geometry ,
(2) the sampling technique ( 1992 , 1998 ),
(3) the role of molecular opacities ,
(4) the role of hydrodynamics (e.g., A&A 1999 and A&A 1998 ),
(5) testing the models against spectral observations from space (e.g., our ISO_spectra of carbon stars), and from the ground (e.g., complete AGB carbon star spectra from 5000 AA to 2.5 mu_m, and high-resolution SiO_spectra of M-type giants).
A major obstacle for progress in this field has during a few decades been the lack of input data for the modelling. A substantial part of my effort in the field has therefore been to perform quantum mechanical computations of molecular line lists and other crucial input data. A review of the data base that has been one outcome of this work was described in a review paper at IAU Symposium 178. A describtion of the quantum mechanical methods we have been using was given in our first papers on the absorption coefficient of HCN and C3 . A recent paper in the work of constructing a molecular opacity data base is the calculation of the absorption coefficient for water . See also the separate description of the SCAN molecular data base below.
(4) The formation and evolution of the solar system.
My contribution to this field has mainly been
concerning the origin of the material which the solar system is made of. We have
silicon_carbide grains from carbonaceous chondrite
meteorites and measured their optical properties. By including these data in
atmospheric modelling it is in principle possible to trace the stellar origin of
the material that became the solar system.
My original ideas about origin of the meteoritic extrasolar
diamond (and SiC) dust
in carbon stars were presented in paper in Nature in 1988. A recent description of our
ideas about the stellar-meteoritic connection
was presented at IAU Symposium 177.
I have also contributed to the solar system research with preditions and speculations about what will happen to the Sun and the Earth during the final phases of the evolution of the Sun (a short proceeding and a longer A&A paper, emphasizing different aspects), and with aspecta of the formation of the solar nebula and the formation of the Earth and its oceans (work in preparation).
I regularly publish popular articles in various journals, recently:
Naturens Verden about Tycho Brahe (NV, vol.84, nr.10, p26-31)
Naturens Verden about the origin or the Earth's oceans (NV, vol.85, nr.2, p2-13),
Aktuel Astronomi about exoplanets (AA, 2004 nr 2, p.16-19),
Kvant about the formation of solar systems (vol.15 nr.3, 2004, p.8-14),
Kvant about the Deep Impact collision with Comet Tempel (vol.16 nr.3, 2005, p.11,12,36),
Universitetets Almanak 2006 about exoplanets (2006).