Andrew Yee
November 26th 05, 04:54 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-2005/pr-29-05.html
--------------------------------------------------------------
Contacts
Fabien Malbet
Laboratoire d'Astrophysique de Grenoble (LAOG), France
Phone: +33 (0) 47 663 58 33
Armando Domiciano de Souza
Phone: +33 (0) 49 207 65 75
For immediate release: 24 November 2005
ESO Press Release 29/05
Sharp Vision Reveals Intimacy of Stars
AMBER instrument on VLTI Probes Environment of Stars
Using the newly installed AMBER instrument on ESO's Very Large
Telescope Interferometer, which combines the light from two
or three 8.2-m Unit Telescopes thereby amounting to observe
with a telescope of 40 to 90 metres in diameter, two
international teams of astronomers observed with unprecedented
detail the environment of two stars. One is a young, still-
forming star and the new results provide useful information
on the conditions leading to the creation of planets. The
other is on the contrary a star entering the latest stages of
its life. The astronomers found, in both cases, evidence for
a surrounding disc.
ESO PR Photo 36a/05
The Young Stellar Object MWC 297 (Artist's View)
A first group of astronomers [1], led by Fabien Malbet from
the Laboratoire d'Astrophysique de Grenoble, France, studied
the young 10-solar mass stellar object MWC 297, which is
still in the very early stage of its life [2].
"This scientific breakthrough opens the doors to an especially
detailed scrutiny of the very close environment of young stars
and will bring us invaluable knowledge on how planets form",
says Malbet.
It is amazing to see the amount of details the astronomers
could achieve while observing an object located more than
800 light-years away and hidden by a large amount of gas and
dust. They found the object to be surrounded by a proto-
planetary disc extending to about the size of our Solar
System, but truncated in his inner part until about half
the distance between the Earth and the Sun. Moreover, the
scientists found the object to be surrounded by an outflowing
wind, the velocity of which increased by a factor 9, from
about 70 km/s near the disc to 600 km/s in the polar regions
[3].
"The reason why the inner part of the disc should be truncated
is not clear", adds Malbet. "This raises new questions on the
physics of the environment of intermediate mass young stars."
The astronomers now plan to perform observations with AMBER [4]
with three telescopes to measure departure from symmetry of the
material around MWC 297.
ESO PR Photo 36b/05
The B[e] Supergiant CPD -57o2874 (Artist's View)
Another international team of astronomers [5] has just done
this kind of observations to study the surroundings of a star
entering the last stages of its life. In a world premiere,
they combined with AMBER the light of three 8.2-m Unit
Telescopes of the VLT, gaining unsurpassed knowledge on a
B[e] supergiant, a star that is more luminous than our Sun
by more than a factor 10,000. This supergiant star is located
ten times further away than MCW 297 at more than 8,000 light-
years.
The astronomers made the observations to investigate the
crucial questions concerning the origin, geometry, and
physical structure of the envelope surrounding the star.
These unique observations have allowed the scientists to
see structures on scale as small as 1.8 thousandths of an
arcsecond -- that is the same as distinguishing between the
headlights of a car from about 230,000 km away, or slightly
less than 2/3 of the distance from the Earth to the Moon!
Armando Domiciano de Souza, from the MPI für Radioastronomie
in Bonn (Germany) and his colleagues made also use of the
MIDI instrument on the VLTI [6], using two Unit Telescopes.
Using their full dataset, they found the circumstellar
envelope around the supergiant to be non-spherical, most
probably because the star is also surrounded by an
equatorial disc made of hot dust and a strong polar wind.
"These observations are really opening the doors for a
new era of understanding of these complex and intriguing
objects", says Domiciano de Souza.
"Such results could be achieved only due to the spectral
resolution as well as spatial resolution that AMBER offers.
There isn't any similar instrument in the world," concludes
Fabien Malbet, who is also the AMBER Project Scientist.
More information
The results presented in this press release are described
in two papers to be published in the leading research
journal, Astronomy and Astrophysics and are available, as
PDF file, from the publisher web site: "Disk and wind
interaction in the young stellar object MWC 297 spatially
resolved with VLT/AMBER" by F. Malbet et al., "VLTI/AMBER
and VLTI/MIDI spectro-interferometric observations of the
B[e] supergiant CPD -57o 2874" by A. Domiciano de Souza et
al.
Press releases on the MCW 297 results are also published in
French by the CNRS, in Italian by INAF, and in German by
the Max-Planck Institute.
Notes
[1]: The team of astronomers having conducted the study of
MCW 297 with AMBER and ISAAC is composed of : F. Malbet ,
M. Benisty , W.J. De Wit, E. Tatulli, and J.-P. Berger
(Laboratoire d'Astrophysique de Grenoble - LAOG, France),
S. Kraus, K.-H. Hofmann, T. Preibisch, and G. Weigelt (Max-
Planck Institut für Radioastronomie, Bonn, Germany), A.
Meilland, O. Chesneau, and P. Stee (Laboratoire Gemini,
Observatoire de la Côte d'Azur, France), R. Petrov
(Laboratoire Universitaire d'Astrophysique de Nice - LUAN,
France), A. Isella and L. Testi (INAF-Osservatorio
Astrofisico di Arcetri, Italy), F. Millour (LAOG and LUAN),
and their colleagues.
[2]: If the lifetime of the Sun were scaled to that of a
human, the Sun would be starting his forties, whereas the
star MWC 297 would just be a 1-3 day old newborn. The B[e]
supergiant on the other hand would be almost 80 years old.
[3]: MWC 297 was observed during the second night of the
first commissioning run of the AMBER instrument on the
Kueyen-Melipal (47m) baseline of the VLTI. Additional
observations were made using the ISAAC near-infrared
spectrograph attached to Antu.
[4]: The Astronomical Multiple BEam Recombiner (AMBER) is
a near-infrared, multi-beam interferometric instrument,
combining simultaneously 3 telescopes. It was built in
collaboration with ESO by a consortium of French, German
and Italian institutes. It is offered to the users since
October 2005. For more information, see the AMBER homepage.
A press release about the First Light is available as ESO
Press Release 07/04.
[5]: The study of the B[e] supergiant, named CPD -57o 2874,
was made by A. Domiciano de Souza, T. Driebe, K.-H. Hofmann,
S. Kraus, K. Ohnaka, Th. Preibisch, and G. Weigelt (Max-
Planck-Institut für Radioastronomie, Bonn, Germany), O.
Chesneau and P. Stee (Observatoire de la Côte d'Azur,
Gemini, France), A. S. Miroshnichenko (MPfR, Bonn, Germany
and Dept. of Physics and Astronomy, University of North
Carolina at Greensboro, USA), R. G. Petrov (Lab. Univ.
d'Astrophysique de Nice, France), F. Lisi (INAF-Osservatorio
Astrof. Di Arcetri, Italy), F. Malbet (Laboratoire
d'Astrophysique de Grenoble, France), and A. Richichi (ESO,
Garching, Germany).
[6]: MIDI is the mid-infrared (8 to 13 microns) instrument
of the VLT interferometer. It combines two beams (either
from the 8.2-m Unit Telescopes or from the 1.8-m Auxiliary
Telescopes).
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-2005/pr-29-05.html
--------------------------------------------------------------
Contacts
Fabien Malbet
Laboratoire d'Astrophysique de Grenoble (LAOG), France
Phone: +33 (0) 47 663 58 33
Armando Domiciano de Souza
Phone: +33 (0) 49 207 65 75
For immediate release: 24 November 2005
ESO Press Release 29/05
Sharp Vision Reveals Intimacy of Stars
AMBER instrument on VLTI Probes Environment of Stars
Using the newly installed AMBER instrument on ESO's Very Large
Telescope Interferometer, which combines the light from two
or three 8.2-m Unit Telescopes thereby amounting to observe
with a telescope of 40 to 90 metres in diameter, two
international teams of astronomers observed with unprecedented
detail the environment of two stars. One is a young, still-
forming star and the new results provide useful information
on the conditions leading to the creation of planets. The
other is on the contrary a star entering the latest stages of
its life. The astronomers found, in both cases, evidence for
a surrounding disc.
ESO PR Photo 36a/05
The Young Stellar Object MWC 297 (Artist's View)
A first group of astronomers [1], led by Fabien Malbet from
the Laboratoire d'Astrophysique de Grenoble, France, studied
the young 10-solar mass stellar object MWC 297, which is
still in the very early stage of its life [2].
"This scientific breakthrough opens the doors to an especially
detailed scrutiny of the very close environment of young stars
and will bring us invaluable knowledge on how planets form",
says Malbet.
It is amazing to see the amount of details the astronomers
could achieve while observing an object located more than
800 light-years away and hidden by a large amount of gas and
dust. They found the object to be surrounded by a proto-
planetary disc extending to about the size of our Solar
System, but truncated in his inner part until about half
the distance between the Earth and the Sun. Moreover, the
scientists found the object to be surrounded by an outflowing
wind, the velocity of which increased by a factor 9, from
about 70 km/s near the disc to 600 km/s in the polar regions
[3].
"The reason why the inner part of the disc should be truncated
is not clear", adds Malbet. "This raises new questions on the
physics of the environment of intermediate mass young stars."
The astronomers now plan to perform observations with AMBER [4]
with three telescopes to measure departure from symmetry of the
material around MWC 297.
ESO PR Photo 36b/05
The B[e] Supergiant CPD -57o2874 (Artist's View)
Another international team of astronomers [5] has just done
this kind of observations to study the surroundings of a star
entering the last stages of its life. In a world premiere,
they combined with AMBER the light of three 8.2-m Unit
Telescopes of the VLT, gaining unsurpassed knowledge on a
B[e] supergiant, a star that is more luminous than our Sun
by more than a factor 10,000. This supergiant star is located
ten times further away than MCW 297 at more than 8,000 light-
years.
The astronomers made the observations to investigate the
crucial questions concerning the origin, geometry, and
physical structure of the envelope surrounding the star.
These unique observations have allowed the scientists to
see structures on scale as small as 1.8 thousandths of an
arcsecond -- that is the same as distinguishing between the
headlights of a car from about 230,000 km away, or slightly
less than 2/3 of the distance from the Earth to the Moon!
Armando Domiciano de Souza, from the MPI für Radioastronomie
in Bonn (Germany) and his colleagues made also use of the
MIDI instrument on the VLTI [6], using two Unit Telescopes.
Using their full dataset, they found the circumstellar
envelope around the supergiant to be non-spherical, most
probably because the star is also surrounded by an
equatorial disc made of hot dust and a strong polar wind.
"These observations are really opening the doors for a
new era of understanding of these complex and intriguing
objects", says Domiciano de Souza.
"Such results could be achieved only due to the spectral
resolution as well as spatial resolution that AMBER offers.
There isn't any similar instrument in the world," concludes
Fabien Malbet, who is also the AMBER Project Scientist.
More information
The results presented in this press release are described
in two papers to be published in the leading research
journal, Astronomy and Astrophysics and are available, as
PDF file, from the publisher web site: "Disk and wind
interaction in the young stellar object MWC 297 spatially
resolved with VLT/AMBER" by F. Malbet et al., "VLTI/AMBER
and VLTI/MIDI spectro-interferometric observations of the
B[e] supergiant CPD -57o 2874" by A. Domiciano de Souza et
al.
Press releases on the MCW 297 results are also published in
French by the CNRS, in Italian by INAF, and in German by
the Max-Planck Institute.
Notes
[1]: The team of astronomers having conducted the study of
MCW 297 with AMBER and ISAAC is composed of : F. Malbet ,
M. Benisty , W.J. De Wit, E. Tatulli, and J.-P. Berger
(Laboratoire d'Astrophysique de Grenoble - LAOG, France),
S. Kraus, K.-H. Hofmann, T. Preibisch, and G. Weigelt (Max-
Planck Institut für Radioastronomie, Bonn, Germany), A.
Meilland, O. Chesneau, and P. Stee (Laboratoire Gemini,
Observatoire de la Côte d'Azur, France), R. Petrov
(Laboratoire Universitaire d'Astrophysique de Nice - LUAN,
France), A. Isella and L. Testi (INAF-Osservatorio
Astrofisico di Arcetri, Italy), F. Millour (LAOG and LUAN),
and their colleagues.
[2]: If the lifetime of the Sun were scaled to that of a
human, the Sun would be starting his forties, whereas the
star MWC 297 would just be a 1-3 day old newborn. The B[e]
supergiant on the other hand would be almost 80 years old.
[3]: MWC 297 was observed during the second night of the
first commissioning run of the AMBER instrument on the
Kueyen-Melipal (47m) baseline of the VLTI. Additional
observations were made using the ISAAC near-infrared
spectrograph attached to Antu.
[4]: The Astronomical Multiple BEam Recombiner (AMBER) is
a near-infrared, multi-beam interferometric instrument,
combining simultaneously 3 telescopes. It was built in
collaboration with ESO by a consortium of French, German
and Italian institutes. It is offered to the users since
October 2005. For more information, see the AMBER homepage.
A press release about the First Light is available as ESO
Press Release 07/04.
[5]: The study of the B[e] supergiant, named CPD -57o 2874,
was made by A. Domiciano de Souza, T. Driebe, K.-H. Hofmann,
S. Kraus, K. Ohnaka, Th. Preibisch, and G. Weigelt (Max-
Planck-Institut für Radioastronomie, Bonn, Germany), O.
Chesneau and P. Stee (Observatoire de la Côte d'Azur,
Gemini, France), A. S. Miroshnichenko (MPfR, Bonn, Germany
and Dept. of Physics and Astronomy, University of North
Carolina at Greensboro, USA), R. G. Petrov (Lab. Univ.
d'Astrophysique de Nice, France), F. Lisi (INAF-Osservatorio
Astrof. Di Arcetri, Italy), F. Malbet (Laboratoire
d'Astrophysique de Grenoble, France), and A. Richichi (ESO,
Garching, Germany).
[6]: MIDI is the mid-infrared (8 to 13 microns) instrument
of the VLT interferometer. It combines two beams (either
from the 8.2-m Unit Telescopes or from the 1.8-m Auxiliary
Telescopes).
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
--------------------------------------------------------------