ROYAL ASTRONOMICAL SOCIETY PRESS INFORMATION NOTE
16th April 2009
EMBARGOED UNTIL 0001 BST, 23RD APRIL 2009
Ref.: RAS PN 09/36 (NAM 23)

Issued by:

Dr Robert Massey
Press and Policy Officer
Royal Astronomical Society
Burlington House
Piccadilly
London W1J 0BQ
Tel: +44 (0)20 7734 3307 / 4582
Mob: +44 (0)794 124 8035
E-mail: rm@ras.org.uk

and

Anita Heward
Press Officer
Royal Astronomical Society
Mob: +44 (0)7756 034 243
E-mail: anitaheward@btopenworld.com

RAS website: http://www.ras.org.uk

EWASS meeting press room (20th – 23rd April only)
Tel:
+44 (0)1707 285530
+44 (0)1707 285640
+44 (0)1707 285781
+44 (0)1707 285587

EWASS home page: http://www.jenam2009.eu (map of campus at http://www.star.herts.ac.uk/ewass)

EWASS press page: http://www.star.herts.ac.uk/ewass/press
Username: ewass
Password: astro@uh

RAS PN 09/36 (NAM 23, EMBARGOED): SHADOW OF A FORMING STAR

A team of astronomers from the Instituto Astrofisica Canarias (IAC) have found an interesting shadow cast by a forming star system. Team member Dr Basmah Riaz, an ER fellow for the Marie Curie CONSTELLATION network, will present the results of their work on Thursday 23rd April in a poster at the European Week of Astronomy and Space Science conference at the University of Hertfordshire.

In March 2008 the scientists observed the young star (protostar) system 2M171123 in the B59 molecular cloud, with the Cerro Tololo Inter-American Observatory (CTIO) 4-m telescope in Chile. They found an odd feature in their image – a shadowed dark lane just to the west of the protostar with a thickness of about 54 billion kilometres (360 times the distance from the Earth to the Sun).

Silhouetted images of young star systems and the disks that often surround them (some of which will go on to form planets) are common. But interestingly, in this case the shadow is offset from the protostar, and the offset has been confirmed by comparing the position of this system in the CTIO observations by another at infrared wavelengths from the NASA Spitzer Space Telescope.

Explaining their result, the team suggests a scenario in which the protostar casts its shadow onto a nearby background cloud of material. A scattering cloud that lies offset from the star acts as a screen onto which its shadow is projected. The team has also confirmed that this is not an edge-on disk, but a system viewed at an intermediate inclination.

This is thus an interesting new observation of an offset shadowed lane among young stellar objects. In the future the team plan to obtain images of the system at higher resolution and look out for any variability in the shadowed lane over time.

CONTACTS

Dr Basmah Riaz
Instituto Astrofisica Canarias
C/ Via Lactea, s/n
E38205
La Laguna (Tenerife)
Spain
Tel: +34 922-605-741
E-mail: basmah@iac.es

Helene Murphy
Media & PR Officer
University of Hertfordshire
Tel: +44 (0)1707 28 4095
E-mail: h.1.murphy@herts.ac.uk

IMAGE

An image of the result can be found at http://www.iac.es/galeria/nlodieu/zoomCTIO3.jpg

Figure caption: A false color image of 2M171123 taken with the CTIO 4-m telescope. The label ‘a’ marks the protostar 2M171123 and the label ‘b’ represents its probable shadow. At the distance of 424 light years to the system, each side of the image frame corresponds to about 3 million million million (trillion) km.

NOTES FOR EDITORS

The CONSTELLATION network

As well as Dr Riaz, other members of the team include Dr. E. L. Martin (IAC), Dr. H. Bouy (IAC) and R. Tata (University of Central Florida, USA).

THE EUROPEAN WEEK OF ASTRONOMY AND SPACE SCIENCE

More than 1000 astronomers and space scientists will gather at the University of Hertfordshire for the European Week of Astronomy and Space Science (EWASS), incorporating the 2009 Royal Astronomical Society National Astronomy Meeting (RAS NAM 2009) and the European Astronomical Society Joint Meeting (JENAM 2009). The meeting runs from 20th to 23rd April 2009.

EWASS is held in conjunction with the UK Solar Physics (UKSP) and Magnetosphere Ionosphere and Solar-Terrestrial Physics (MIST) meetings. The conference includes scientific sessions organised by the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) and the European Space Agency (ESA).

EWASS is principally sponsored by the Royal Astronomical Society (RAS), the Science and Technology Facilities Council (STFC) and the University of Hertfordshire, Hatfield.

THE ROYAL ASTRONOMICAL SOCIETY

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.