Andrew Yee
January 25th 06, 08:35 PM
ESO Education and Public Relations Dept.
--------------------------------------------------------------
Text with all links and the photos are available on the ESO
Website at URL:
http://www.eso.org/outreach/press-rel/pr-2006/pr-03-06_p2.html
--------------------------------------------------------------
Contacts
Jean-Philippe Beaulieu
Institut d'Astrophysique de Paris, France
Phone: +33-1-4432-8119
Pascal Fouqué
Observatoire Midi-Pyrénées, France
Phone: +33-5-6133-2786
Martin Dominik
University of St Andrews, UK
Phone: +44-1334-463066
Uffe G. Jørgensen
Niels Bohr Institutet Astronomisk Observatorium, Denmark
Phone: +45-35-32-5998
Daniel Kubas
ESO, Chile
David P. Bennett
University of Notre Dame, USA
Phone: +1-574-631-8298
Andrew Williams
Perth Observatory, Australia
Phone: +61-8-9293-8255
Andrzej Udalski
Warsaw University Observatory, Poland
Phone: +48-22-553 05 07
Joachim Wambsganss
Zentrum für Astronomie der Universitüt Heidelberg, Germany
Phone: +49-6221-54-1800
Under Embargo till 25 January, 2006, 19:00 CET
ESO Science Release 03/06
It's Far, It's Small, It's Cool: It's an Icy Exoplanet!
Distant Planet Brings Astronomers Closer To Home
Since the discovery ten years ago of the first planet orbiting
a normal star other than the Sun, 170 of these 'exoplanets' are
now known, belonging to 147 planetary systems. These exoplanets
come in very different masses -- from below the mass of Neptune
to several times the mass of the largest of the planets in our
Solar System, Jupiter -- and properties: some indeed are very
close to their host star, completing a circle in just a little
above a day, while others have very elongated orbits, the
closest distance to their parent star being more than ten times
smaller than the farthest.
In this sense, the exoplanets discovered until now were very
different from what astronomers previously thought should exist,
taking the Solar System as a role model. When they started their
observing campaigns, the scientists were indeed looking for giant
planets in nearly circular orbits that are rather far from their
star. The new discoveries meant they had to reconsider their
ideas about the formation of planets and introduce new
mechanisms, such as 'orbital migration'.
The discovery announced today of a planet that seems to follow
the earliest expectations is thus a relief for the astronomers
as it shows that the Solar System must not be unique in its
characteristics. What's more the newly found exoplanet is also
most probably the smallest found orbiting a normal star, with
a mass of only 5 times the mass of the Earth.
"This planet is actually the first and only planet that has been
discovered so far that is in agreement with the theories for how
our Solar System formed ", said Uffe Gråe Jørgensen (Niels Bohr
Institute, Copenhagen, Denmark), member of the team.
Fitting the Picture
ESO PR Photo 03a/06
Artist's Impression of the Newly Found Exoplanet
The new planet, designated by the unglamorous identifier of
OGLE-2005-BLG-390Lb, orbits a red dwarf star five times less
massive than the Sun. Such red dwarfs are the most common stars
of our Galaxy: in the close vicinity of the Sun for example,
there are more than 10 times more red dwarfs than solar-like
stars. Finding planets around such stars is thus an important
step for a complete census of alien worlds.
The favoured theoretical explanation for the formation of
planetary systems proposes that solid 'planetesimals' accumulate
to build up planetary cores, which then accrete nebular gas --
to form giant planets -- if they are sufficiently massive.
Around red dwarfs, this model favours the formation of Earth-
to Neptune-mass planets being between 1 and 10 times the Earth-
Sun distance away from their host. The newly found exoplanet
fits thus perfectly into this picture.
OGLE-2005-BLG-390Lb is about 3 times further away from its host
star than the Earth is from the Sun. It is thus at the same
location as the main asteroid belt in the Solar System. Given
the lower mass of the parent star, however, the planet takes
10 years to accomplish a full circle (asteroids do that in
about 5 years).
The relatively cool and faint parent star and large orbit implies
that the likely surface temperature of the planet is 220 degrees
Centigrade below zero, too cold for liquid water. It is likely
to have a thin atmosphere, like the Earth, but its rocky surface
is probably deeply buried beneath frozen oceans. It may therefore
more closely resemble a more massive version of Pluto, rather
than the rocky inner planets like Earth and Venus.
Einstein's Prediction
Most of the exoplanets detected so far have been found by
an indirect method -- the measurement of stellar velocity
variations. It is based on the gravitational pull of the
orbiting planet that causes the central star to move a little
back and forth; the heavier the planet, the greater is the
associated change in the star's velocity. Certainly the best
instrument for this kind of research is the HARPS spectrograph
(High Accuracy Radial Velocity Planet Searcher), on the 3.6-m
telescope at the ESO La Silla Observatory. HARPS can measure
such stellar motions with an unrivalled accuracy of about 1
metre per second (m/s), cf. ESO PR 06/03 and was therefore able
to find several exoplanets, including the first discovered rocky
planet, having a mass of 13 times the mass of the Earth.
The newly discovered planet on the other hand is one of the
few to have been discovered by the microlensing technique.
The light from a distant star is affected by the gravity of the
objects it passes on its way to us. This effect was predicted
by Albert Einstein early last century and observationally
confirmed in 1919 when a solar eclipse allowed the study of
stars close to the line of sight of the Sun. Accurate positional
measurements showed that the light from those remote stars was
bent by the Sun's gravitational field.
However, the light may not only be deflected, it can also be
amplified. In that case, the intervening object works like a
giant 'magnifying lens' that concentrates the light from the
distant source.
Effects of gravitational optics in space were first observed in
1979. When produced by extended, very heavy clusters of galaxies,
they may appear as large, spectacular arcs and well-separated
multiple images, cf. ESO PR Photos 46d/98 and 46f/98. Less
massive lenses, however, produce images with extensions that
are too small to be distinguished directly.
Microlensing
Such 'microlensing' effects occur when a compact body (usually
a Milky Way star moving in its galactic orbit) passes almost
directly between the observer and a luminous background object
(usually also a star). One then sees that the brightness of
that object rises and falls as the lens passes across the line-
of-sight. The observed light intensity is described by a so-
called "light curve", cf. PR Photo 16a/01. Normally, the lensing
object is a faint low-mass star, one of the most common objects
in the Milky Way.
In most cases, these low-mass stars are too faint to be directly
observed. This is especially so in crowded sky fields in which
there are many much brighter stars -- including the luminous
giant stars that are monitored for microlensing effects. However,
the gravity of a low-mass star is strong enough to produce a
lensing effect if the geometrical alignment is sufficiently
precise. This happens rarely, but by looking at a large number
of background stars, it has been possible to detect a fair
number of microlensing events during the past few years.
International collaborations like the Optical Gravitational
Lensing Experiment (OGLE) and the Microlensing Observations in
Astrophysics (MOA) collaboration scan the skies continuously for
such microlensing events which typically last from a few weeks
to some months. When a star is found to brighten in a way that
looks like what is expected from microlensing, they send
electronic alerts to other dedicated teams like Probing Lensing
Anomalies NETwork (PLANET) and Microlensing Planet Search Project
(MPS) who then intensively monitor the possible lensing events.
One of the main goals of these research programmes is to search
for "dark matter". Indeed, microlensing effects are excellent
tools for learning more about this mysterious component of the
Universe, as they provide information about lensing objects
that otherwise are too faint to be observed.
However, microlensing events may also provide very useful
information about the background object (the "source"), the
light of which is amplified and magnified .
"The probability that a given star undergoes a microlensing
event at a given time is only about one in a million", explained
Andrzej Udalski (Warsaw University Observatory, Poland), leader
of the Polish-American OGLE team. "However, with more than 100
million stars being routinely monitored by OGLE each night with
the Warsaw 1.3m telecope at Las Campanas Observatory (Chile),
we can provide the scientific community with about 120 ongoing
events and nearly 1000 events per year."
Finding a Planet with PLANET
"With this method, we let the gravity of a dim, intervening star
act as a giant natural telescope for us, magnifying a more
distant star, which then temporarily looks brighter", explained
team member Andrew Williams (Perth Observatory, Australia). "A
small 'defect' in the brightening reveals the existence of a
planet around the lens star. We don't see the planet, or even
the star that it's orbiting, we just see the effect of their
gravity."
Such an intervening star causes a characteristic brightening that
lasts about a month. Any planets orbiting this star can produce
an additional signal, lasting days for giant planets down to
hours for Earth-mass planets.
ESO PR Photo 03b/06
Light Curve of OGLE-2005-BLG-390
In order to be able to catch and characterize these planets,
nearly-continuous round-the-clock high-precision monitoring of
ongoing microlensing events is required. This is achieved by
the PLANET network of 1m-class telescopes consisting of the ESO
1.54m Danish at La Silla (Chile), the Canopus Observatory 1.0m
(Hobart, Tasmania, Australia), the Perth 0.6m (Bickley, Western
Australia), the Boyden 1.5m (South Africa), and the SAAO 1.0m
(Sutherland, South Africa). Since 2005, PLANET operates a common
campaign with RoboNet, a UK operated network of 2m fully robotic
telescopes currently comprising the Liverpool Telescope (Roque
de Los Muchachos, La Palma, Spain) and the Faulkes Telescope
North (Haleakala, Hawaii, USA).
The OGLE serach team discovered the event OGLE-2005-BLG-390 on
11 July 2005, triggering the PLANET telescopes to start taking
data. A light curve consistent with a single lens star peaking
at an amplification of about 3 on 31 July 2005 was observed,
until 10 August when PLANET member Pascal Fouqué, observing at
the Danish 1.54m at ESO La Silla, noticed a planetary deviation.
An OGLE point from the same night showed the same trend, while
the last half of the planetary deviation, lasting about a day,
had been covered by images from Perth Observatory. The MOA
collaboration was later able to identify the source star on
its images and confirmed the deviation.
Distant but Common
The fact that the newly found exoplanet was discovered through
the microlensing technique explains why it is also the farthest
found. The OGLE indeed monitors the region towards the Centre
of the Milky Way were many stars are present, increasing the
odds of an event. The parent star lies thus close to the Centre
and is therefore more than 20 000 light-years away. On the other
hand, to find exoplanet with the radial velocity technique, one
need the stars to be bright -- and hence rather close -- to be
able to study them into detail.
OGLE 2005-BLG-390Lb is only the third extra-solar planet
resulting so far from microlensing searches. The other two
microlensing planets, detected in events OGLE 2003-BLG-235/MOA
2003-BLG-053 and OGLE 2005-BLG-071 have masses of a few times
that of Jupiter. Thus Jupiter- or Saturn-like gas giant planets,
which are much easier to detect than less massive rocky/icy
planets, appear to be rare around red dwarfs. Since microlensing
relies on the gravity of the lens star, rather than on its light,
these are favoured due to their large abundance and constituted
the parent star for all three detected planets. The discovery of
a rocky/icy planet already as the third one detected through
microlensing is a strong hint that, in contrast to massive gas
giants, these objects are quite common, in qualitative agreement
with the prediction from theoretical models.
The microlensing technique is most probably the only method
currently capable of detecting planets similar to Earth. "The
search for a second Earth is the driving force behind our
research and this discovery constitutes a major leap forward
since it is the most Earth-like planet we know of so far",
said co-author Daniel Kubas, from ESO.
High resolution images and their captions are available on this
page.
This press release is also accompanied by Broadcast quality material,
http://www.eso.org/outreach/press-rel/pr-2006/vid-03-06.html
ESO Media Contacts are on the Public Affairs Dept. Contact page.
National contacts for the media:
Belgium: Dr. Rodrigo Alvarez, +32-2-474 70 50
Finland: Ms. Terhi Loukiainen, +358 9 7748 8385
Denmark: Dr. Michael Linden-Vørnle, +45-33-18 19 97
France: Dr. Daniel Kunth, +33-1-44 32 80 85
Germany: Dr. Jakob Staude, +49-6221-528229
Italy: Prof. Massimo Capaccioli, +39-081-55 75 511
The Netherlands: Ms. Marieke Baan, +31-20-525 74 80
Portugal: Prof. Teresa Lago, +351-22-089 833
Sweden: Dr. Jesper Sollerman, +46-8-55 37 85 54
Switzerland: Dr. Martin Steinacher, +41-31-324 23 82
United Kingdom: Mr. Peter Barratt, +44-1793-44 20 25
--------------------------------------------------------------
ESO Press Information is available on the WWW at
http://www.eso.org/outreach/press-rel/
--------------------------------------------------------------
(c) ESO Education & Public Relations Department
Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany
--------------------------------------------------------------
--------------------------------------------------------------
Text with all links and the photos are available on the ESO
Website at URL:
http://www.eso.org/outreach/press-rel/pr-2006/pr-03-06_p2.html
--------------------------------------------------------------
Contacts
Jean-Philippe Beaulieu
Institut d'Astrophysique de Paris, France
Phone: +33-1-4432-8119
Pascal Fouqué
Observatoire Midi-Pyrénées, France
Phone: +33-5-6133-2786
Martin Dominik
University of St Andrews, UK
Phone: +44-1334-463066
Uffe G. Jørgensen
Niels Bohr Institutet Astronomisk Observatorium, Denmark
Phone: +45-35-32-5998
Daniel Kubas
ESO, Chile
David P. Bennett
University of Notre Dame, USA
Phone: +1-574-631-8298
Andrew Williams
Perth Observatory, Australia
Phone: +61-8-9293-8255
Andrzej Udalski
Warsaw University Observatory, Poland
Phone: +48-22-553 05 07
Joachim Wambsganss
Zentrum für Astronomie der Universitüt Heidelberg, Germany
Phone: +49-6221-54-1800
Under Embargo till 25 January, 2006, 19:00 CET
ESO Science Release 03/06
It's Far, It's Small, It's Cool: It's an Icy Exoplanet!
Distant Planet Brings Astronomers Closer To Home
Since the discovery ten years ago of the first planet orbiting
a normal star other than the Sun, 170 of these 'exoplanets' are
now known, belonging to 147 planetary systems. These exoplanets
come in very different masses -- from below the mass of Neptune
to several times the mass of the largest of the planets in our
Solar System, Jupiter -- and properties: some indeed are very
close to their host star, completing a circle in just a little
above a day, while others have very elongated orbits, the
closest distance to their parent star being more than ten times
smaller than the farthest.
In this sense, the exoplanets discovered until now were very
different from what astronomers previously thought should exist,
taking the Solar System as a role model. When they started their
observing campaigns, the scientists were indeed looking for giant
planets in nearly circular orbits that are rather far from their
star. The new discoveries meant they had to reconsider their
ideas about the formation of planets and introduce new
mechanisms, such as 'orbital migration'.
The discovery announced today of a planet that seems to follow
the earliest expectations is thus a relief for the astronomers
as it shows that the Solar System must not be unique in its
characteristics. What's more the newly found exoplanet is also
most probably the smallest found orbiting a normal star, with
a mass of only 5 times the mass of the Earth.
"This planet is actually the first and only planet that has been
discovered so far that is in agreement with the theories for how
our Solar System formed ", said Uffe Gråe Jørgensen (Niels Bohr
Institute, Copenhagen, Denmark), member of the team.
Fitting the Picture
ESO PR Photo 03a/06
Artist's Impression of the Newly Found Exoplanet
The new planet, designated by the unglamorous identifier of
OGLE-2005-BLG-390Lb, orbits a red dwarf star five times less
massive than the Sun. Such red dwarfs are the most common stars
of our Galaxy: in the close vicinity of the Sun for example,
there are more than 10 times more red dwarfs than solar-like
stars. Finding planets around such stars is thus an important
step for a complete census of alien worlds.
The favoured theoretical explanation for the formation of
planetary systems proposes that solid 'planetesimals' accumulate
to build up planetary cores, which then accrete nebular gas --
to form giant planets -- if they are sufficiently massive.
Around red dwarfs, this model favours the formation of Earth-
to Neptune-mass planets being between 1 and 10 times the Earth-
Sun distance away from their host. The newly found exoplanet
fits thus perfectly into this picture.
OGLE-2005-BLG-390Lb is about 3 times further away from its host
star than the Earth is from the Sun. It is thus at the same
location as the main asteroid belt in the Solar System. Given
the lower mass of the parent star, however, the planet takes
10 years to accomplish a full circle (asteroids do that in
about 5 years).
The relatively cool and faint parent star and large orbit implies
that the likely surface temperature of the planet is 220 degrees
Centigrade below zero, too cold for liquid water. It is likely
to have a thin atmosphere, like the Earth, but its rocky surface
is probably deeply buried beneath frozen oceans. It may therefore
more closely resemble a more massive version of Pluto, rather
than the rocky inner planets like Earth and Venus.
Einstein's Prediction
Most of the exoplanets detected so far have been found by
an indirect method -- the measurement of stellar velocity
variations. It is based on the gravitational pull of the
orbiting planet that causes the central star to move a little
back and forth; the heavier the planet, the greater is the
associated change in the star's velocity. Certainly the best
instrument for this kind of research is the HARPS spectrograph
(High Accuracy Radial Velocity Planet Searcher), on the 3.6-m
telescope at the ESO La Silla Observatory. HARPS can measure
such stellar motions with an unrivalled accuracy of about 1
metre per second (m/s), cf. ESO PR 06/03 and was therefore able
to find several exoplanets, including the first discovered rocky
planet, having a mass of 13 times the mass of the Earth.
The newly discovered planet on the other hand is one of the
few to have been discovered by the microlensing technique.
The light from a distant star is affected by the gravity of the
objects it passes on its way to us. This effect was predicted
by Albert Einstein early last century and observationally
confirmed in 1919 when a solar eclipse allowed the study of
stars close to the line of sight of the Sun. Accurate positional
measurements showed that the light from those remote stars was
bent by the Sun's gravitational field.
However, the light may not only be deflected, it can also be
amplified. In that case, the intervening object works like a
giant 'magnifying lens' that concentrates the light from the
distant source.
Effects of gravitational optics in space were first observed in
1979. When produced by extended, very heavy clusters of galaxies,
they may appear as large, spectacular arcs and well-separated
multiple images, cf. ESO PR Photos 46d/98 and 46f/98. Less
massive lenses, however, produce images with extensions that
are too small to be distinguished directly.
Microlensing
Such 'microlensing' effects occur when a compact body (usually
a Milky Way star moving in its galactic orbit) passes almost
directly between the observer and a luminous background object
(usually also a star). One then sees that the brightness of
that object rises and falls as the lens passes across the line-
of-sight. The observed light intensity is described by a so-
called "light curve", cf. PR Photo 16a/01. Normally, the lensing
object is a faint low-mass star, one of the most common objects
in the Milky Way.
In most cases, these low-mass stars are too faint to be directly
observed. This is especially so in crowded sky fields in which
there are many much brighter stars -- including the luminous
giant stars that are monitored for microlensing effects. However,
the gravity of a low-mass star is strong enough to produce a
lensing effect if the geometrical alignment is sufficiently
precise. This happens rarely, but by looking at a large number
of background stars, it has been possible to detect a fair
number of microlensing events during the past few years.
International collaborations like the Optical Gravitational
Lensing Experiment (OGLE) and the Microlensing Observations in
Astrophysics (MOA) collaboration scan the skies continuously for
such microlensing events which typically last from a few weeks
to some months. When a star is found to brighten in a way that
looks like what is expected from microlensing, they send
electronic alerts to other dedicated teams like Probing Lensing
Anomalies NETwork (PLANET) and Microlensing Planet Search Project
(MPS) who then intensively monitor the possible lensing events.
One of the main goals of these research programmes is to search
for "dark matter". Indeed, microlensing effects are excellent
tools for learning more about this mysterious component of the
Universe, as they provide information about lensing objects
that otherwise are too faint to be observed.
However, microlensing events may also provide very useful
information about the background object (the "source"), the
light of which is amplified and magnified .
"The probability that a given star undergoes a microlensing
event at a given time is only about one in a million", explained
Andrzej Udalski (Warsaw University Observatory, Poland), leader
of the Polish-American OGLE team. "However, with more than 100
million stars being routinely monitored by OGLE each night with
the Warsaw 1.3m telecope at Las Campanas Observatory (Chile),
we can provide the scientific community with about 120 ongoing
events and nearly 1000 events per year."
Finding a Planet with PLANET
"With this method, we let the gravity of a dim, intervening star
act as a giant natural telescope for us, magnifying a more
distant star, which then temporarily looks brighter", explained
team member Andrew Williams (Perth Observatory, Australia). "A
small 'defect' in the brightening reveals the existence of a
planet around the lens star. We don't see the planet, or even
the star that it's orbiting, we just see the effect of their
gravity."
Such an intervening star causes a characteristic brightening that
lasts about a month. Any planets orbiting this star can produce
an additional signal, lasting days for giant planets down to
hours for Earth-mass planets.
ESO PR Photo 03b/06
Light Curve of OGLE-2005-BLG-390
In order to be able to catch and characterize these planets,
nearly-continuous round-the-clock high-precision monitoring of
ongoing microlensing events is required. This is achieved by
the PLANET network of 1m-class telescopes consisting of the ESO
1.54m Danish at La Silla (Chile), the Canopus Observatory 1.0m
(Hobart, Tasmania, Australia), the Perth 0.6m (Bickley, Western
Australia), the Boyden 1.5m (South Africa), and the SAAO 1.0m
(Sutherland, South Africa). Since 2005, PLANET operates a common
campaign with RoboNet, a UK operated network of 2m fully robotic
telescopes currently comprising the Liverpool Telescope (Roque
de Los Muchachos, La Palma, Spain) and the Faulkes Telescope
North (Haleakala, Hawaii, USA).
The OGLE serach team discovered the event OGLE-2005-BLG-390 on
11 July 2005, triggering the PLANET telescopes to start taking
data. A light curve consistent with a single lens star peaking
at an amplification of about 3 on 31 July 2005 was observed,
until 10 August when PLANET member Pascal Fouqué, observing at
the Danish 1.54m at ESO La Silla, noticed a planetary deviation.
An OGLE point from the same night showed the same trend, while
the last half of the planetary deviation, lasting about a day,
had been covered by images from Perth Observatory. The MOA
collaboration was later able to identify the source star on
its images and confirmed the deviation.
Distant but Common
The fact that the newly found exoplanet was discovered through
the microlensing technique explains why it is also the farthest
found. The OGLE indeed monitors the region towards the Centre
of the Milky Way were many stars are present, increasing the
odds of an event. The parent star lies thus close to the Centre
and is therefore more than 20 000 light-years away. On the other
hand, to find exoplanet with the radial velocity technique, one
need the stars to be bright -- and hence rather close -- to be
able to study them into detail.
OGLE 2005-BLG-390Lb is only the third extra-solar planet
resulting so far from microlensing searches. The other two
microlensing planets, detected in events OGLE 2003-BLG-235/MOA
2003-BLG-053 and OGLE 2005-BLG-071 have masses of a few times
that of Jupiter. Thus Jupiter- or Saturn-like gas giant planets,
which are much easier to detect than less massive rocky/icy
planets, appear to be rare around red dwarfs. Since microlensing
relies on the gravity of the lens star, rather than on its light,
these are favoured due to their large abundance and constituted
the parent star for all three detected planets. The discovery of
a rocky/icy planet already as the third one detected through
microlensing is a strong hint that, in contrast to massive gas
giants, these objects are quite common, in qualitative agreement
with the prediction from theoretical models.
The microlensing technique is most probably the only method
currently capable of detecting planets similar to Earth. "The
search for a second Earth is the driving force behind our
research and this discovery constitutes a major leap forward
since it is the most Earth-like planet we know of so far",
said co-author Daniel Kubas, from ESO.
High resolution images and their captions are available on this
page.
This press release is also accompanied by Broadcast quality material,
http://www.eso.org/outreach/press-rel/pr-2006/vid-03-06.html
ESO Media Contacts are on the Public Affairs Dept. Contact page.
National contacts for the media:
Belgium: Dr. Rodrigo Alvarez, +32-2-474 70 50
Finland: Ms. Terhi Loukiainen, +358 9 7748 8385
Denmark: Dr. Michael Linden-Vørnle, +45-33-18 19 97
France: Dr. Daniel Kunth, +33-1-44 32 80 85
Germany: Dr. Jakob Staude, +49-6221-528229
Italy: Prof. Massimo Capaccioli, +39-081-55 75 511
The Netherlands: Ms. Marieke Baan, +31-20-525 74 80
Portugal: Prof. Teresa Lago, +351-22-089 833
Sweden: Dr. Jesper Sollerman, +46-8-55 37 85 54
Switzerland: Dr. Martin Steinacher, +41-31-324 23 82
United Kingdom: Mr. Peter Barratt, +44-1793-44 20 25
--------------------------------------------------------------
ESO Press Information is available on the WWW at
http://www.eso.org/outreach/press-rel/
--------------------------------------------------------------
(c) ESO Education & Public Relations Department
Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany
--------------------------------------------------------------