Dust and gas from Comet 9P/Tempel 1 seen by ESA OGS (Forwarded)

ESA News
http://www.esa.int

5 July 2005

Dust and gas from Comet 9P/Tempel 1 seen by ESA OGS

Dust and gas are seen in these images of Comet 9P/Tempel 1, as observed
with the 1-metre ESA Optical Ground Station (OGS) telescope, located at
the Observatorio del Teide on Tenerife, Canary Islands.

Two different filters have been used in different visible light
observations to study different aspects of the comet's nature. Red
'broadband' filters allowed the detection of dust, while blue
'narrowband' filters, filtering only carbon gaseous compounds, allow the
observations to concentrate mainly on the gas emissions of the comet.

The first set of images here were taken with a broadband red filter,
four days before and about 15 hours after the impact respectively. The
images were exposed for 10 minutes and show the dust coma of the comet.
The dust brightness has increased by 50 percent.

A strong jet has recently appeared as a direct result of the impact,
pointing north-north-east. The overall coma is very asymmetric in
appearance. All structures must have been created by the outburst
triggered by the impact.

The second set of images of Tempel 1 from the OGS telescope use a
narrowband filter (C2 emission band). They show the coma gas mixed with
smaller-sized dust particles than observed in the broadband red filtered
image.

The observations were taken two days before and about 16 hours after the
impact respectively. Also here the coma brightness has increased by 50
percent. Again the same strong jet is visible.

In the third set of images, Tempel 1 is seen about 16 hours after the
impact. The two images show the refection of blue (BC filter) and red
(RC filter) light from the dust cloud surrounding the comet nucleus.

These reflections show different dust particle sizes, with blue
particles being smaller than red particles. It is clear that the jet
structure of the smaller dust particles points towards the north (BC
image), whereas the jet composed of larger dust particles (RC image) is
rotated by about 45 degrees towards the north-east.

This means that the direction in which the dust particles were ejected
from the comet nucleus after impact seems to depend on the particle size.

These images introduce ESA's OGS telescope to the network of Earth-based
observatories already taking part in the one of world's largest
astronomical observation campaigns - looking at results of the 4 July
comet impact event.

For more information:

Rita Schulz, Principal Investigator for OGS observations
ESA-ESTEC (The Netherlands)
E-mail: rita.schulz @ esa.int

More about...

* Rosetta special: ESA views Deep Impact
http://www.esa.int/SPECIALS/Rosetta/index.html
* Rosetta factsheet
http://www.esa.int/esaSC/SEMJUZS1VED_index_0.html
* XMM-Newton factsheet
http://www.esa.int/esaSC/SEM14YS1VED_index_0.html
* Hubble factsheet
http://www.esa.int/esaSC/SEMB5E1A6BD_index_0.html

Related articles

* Life of a comet
http://www.esa.int/SPECIALS/Rosetta/SEM3NV0PGQD_0.html
* Preparing for impact
http://www.esa.int/esaCP/SEM8PE0DU8E_index_0.html
* Tempel 1: Biography of a comet
http://www.esa.int/SPECIALS/Rosetta/SEMIUG0DU8E_0.html
* Rosetta monitors Deep Impact
http://www.esa.int/esaCP/SEMCOZ1DU8E_index_0.html
* XMM-Newton to observe Deep Impact
http://www.esa.int/esaCP/SEMSZC2DU8E_index_0.html
* Hubble sees outburst from Deep Impact comet
http://www.esa.int/esaCP/SEMSBN5DIAE_index_0.html
* ESA observes Deep Impact from Earth
http://www.esa.int/SPECIALS/Rosetta/SEMNRO5DIAE_0.html

Related links

* Watch NASA TV
http://www.nasa.gov/multimedia/nasatv/index_040705.html
* NASA Deep Impact
http://www.nasa.gov/mission_pages/de...ain/index.html
* ESO Deep Impact news
http://www.eso.org/outreach/press-re.../pr-15-05.html
* Arianespace
http://www.arianespace.com
* DLR
http://www.dlr.de
* Astrium Space
http://www.astrium-space.com/

IMAGE CAPTIONS:

[Image 1:
http://www.esa.int/esaCP/SEMQR06DIAE_index_1.html]
Dust from Comet 9P/Tempel 1 seen with the ESA OGS (red filter)

Comet 9P/Tempel 1 observed with the 1-metre ESA Optical Ground Station
(OGS) telescope, Tenerife, Canary Islands. The images here were taken
with a broadband red filter, four days before and about 15 hours after
the impact respectively, and show the dust coma of the comet.

Credits: ESA

[Image 2:
http://www.esa.int/esaCP/SEMQR06DIAE...html#subhead2]
Coma gas from Comet 9P/Tempel 1 seen with the ESA OGS telescope
(narrowband filter)

Comet 9P/Tempel 1 observed with the 1-metre ESA Optical Ground Station
(OGS) telescope, Tenerife, Canary Islands. The images here were taken a
narrowband filter (C2 emission band) showing the coma gas mixed with
smaller-sized dust particles than observed in the broadband red image,
two days before and about 16 hours after the impact respectively.

Credits: ESA

[Image 3:
http://www.esa.int/esaCP/SEMQR06DIAE...html#subhead4]
Dust from Comet 9P/Tempel 1 seen with ESA OGS (blue/red filters)

Comet 9P/Tempel 1 observed with the 1-metre ESA Optical Ground Station
(OGS) telescope about 16 hours after the impact with the comet nucleus.
The two images show the reflection of blue and red light from the dust
cloud surrounding the comet nucleus. These reflections show different
dust particle sizes, with blue particles being smaller than red particles.

Credits: ESA