Herschel Space Observatory investigates gas and dust
in forming and mature planetary systems
The Herschel Space Observatory,
with its 3.5 meter-sized mirror, represents the largest space-based
telescope in the history. It was launched into space in May 2009 and
is now conducting observations in the far-infrared, probing
the coldest dusty and gaseous regions in the Universe.
Herschel observations cover a diversity of objects, ranging from
planets in the Solar System to distant galaxies.
The Astrophysical Institute and the University Observatory Jena
participates in two Open-Time Key Programs of the Herschel mission:
("GAS in Planetary Systems", Jena Co-I: Alexander Krivov)
("DUst around NEarby Stars", Jena Co-Is: Alexander Krivov,
Torsten Loehne, and Harald Mutschke).
The first project, GASPS, aims at detecting and measuring the gas component
in protoplanetary, transitional, and debris disks around stars,
which represent successive evolutionary stages of circumstellar disks.
Dense, gas- and dust-rich protoplanetary disks are envoronments is which planets are formed
around the stars. Debris disks are much more tenous relics of
planet formation; many of them encompass orbits of planets that have formed
The figure on the left shows the oxygen spectral line at 63 microns
in disks of four stars with the ages approximately in the range
from 6 to 12 Myr, which is about the time around which most
protoplanetary disks are believed to lose their primordial gas.
These four sources have brought three unambiguous detections aroung younger objects
and one non-detection around the oldest object (HD 181327).
The second project, DUNES, provides an unbiased search for dusty debris
disks around more than a hundred nearby, solar-type stars. The observed dust
in these disks is thought to be sustained by collisions amongst numerious invisible
small bodies that are left-overs of planetary formation processes.
These bodies are located on the outskirts of the systems and represent
analogs of our Solar System's Kuiper Belt.
The right figure presents a massive, large Kuiper Belt analog of
a nearby star q1 Eridani. It has a radius of about 80 astronomical units
and is about 1000 times more massive than the Kuiper Belt of the Solar System.
The system is known to contain one close-in planet orbiting well inside the debris
ring; more distant planets are expected.
The first scientific results of the Herschel mission have been
recently published in a
special issue of the international journal "Astronomy and Astrophysics".
Six papers in that volume are based on the GASPS and DUNES results and are co-authoured
by Jena astronomers.
More about our research on circumstellar disks
Dr. Torsten Loehne
(Tel.: 03641 / 947531, E-Mail: tloehne[at]astro.uni-jena.de)
Prof. Alexander Krivov
(Tel.: 03641 / 947530, E-Mail: krivov[at]astro.uni-jena.de)