Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble zooms in on heart of mystery comet

16.11.2007
Astronomers have used Hubble’s powerful resolution to study Comet Holmes’ core for clues about how the comet brightened. The orbiting observatory’s Wide Field Planetary Camera 2 (WFPC2) monitored the comet for several days, snapping images on 29 Oct., 31 Oct. and 4 Nov. Hubble’s crisp “eye” can see details as small as 54 kilometres across, providing the sharpest view yet of the source of the spectacular brightening.

The Hubble image at right, taken on 4 Nov., shows the heart of the comet. The central portion of the image has been specially processed to highlight variations in the dust distribution near the nucleus. About twice as much dust lies along the east-west direction (the horizontal direction) as along the north-south direction (the vertical direction), giving the comet a “bow tie” appearance.

The composite colour image at left, taken Nov. 1 by the amateur astronomer Alan Dyer, shows the complex structure of the entire coma, consisting of concentric shells of dust and a faint tail emanating from the comet’s right side.

The nucleus — the small solid body that is the source of the comet’s activity — is still swaddled in bright dust, even 12 days after the spectacular outburst. “Most of what Hubble sees is sunlight scattered from microscopic particles,” explained Hal Weaver of The Johns Hopkins University Applied Physics Laboratory of Laurel, Maryland in the USA, who led the Hubble investigation. “But we may finally be starting to detect the emergence of the nucleus itself in this final Hubble image.”

Hubble first observed Comet 17P/Holmes on June 15, 1999, when there was virtually no dusty shroud around the nucleus. Although Hubble cannot resolve the nucleus, astronomers inferred its size by measuring its brightness. Astronomers deduced that the nucleus’s diameter was approximately 3.4 kilometres, about the distance between the Arc de Triomphe and the Louvre glass pyramid in Paris. They hope to use the new Hubble images to determine the size of the comet’s nucleus to see how much of it was blasted away during the outburst.

Hubble’s two earlier snapshots of Comet Holmes also showed some interesting features. On 29 Oct. the telescope spied three “spurs” of dust emanating from the nucleus while the Hubble images taken on 31 Oct. revealed an outburst of dust just west of the nucleus.

The Hubble images however do not show any large fragments near the nucleus of Comet Holmes, unlike the case of Comet 73P/Schwassmann-Wachmann 3 (SW3). In the spring of 2006 Hubble observations revealed a multitude of “mini-comets” ejected by SW3 after the comet increased dramatically in brightness. Ground-based images of Comet Holmes show a large, spherically symmetrical cloud of dust that is offset from the nucleus, suggesting that a large fragment broke off and subsequently disintegrated into tiny dust particles after moving away from the main nucleus. Unfortunately, the huge amount of dust near the comet’s nucleus and the relatively large distance from Earth (240 million kilometres, or 1.6 astronomical units for Holmes versus 15 million kilometres, 0.1 astronomical units for SW3), conspire to make detecting fragments near Holmes nearly impossible right now, unless the fragments are nearly as large as the nucleus itself.

Lars Christensen | alfa
Further information:
http://www.spacetelescope.org/news/html/heic0718.html

More articles from Physics and Astronomy:

nachricht Extremely close look at electron advances frontiers in particle physics
18.10.2018 | National Science Foundation

nachricht Blue phosphorus -- mapped and measured for the first time
16.10.2018 | Helmholtz-Zentrum Berlin für Materialien und Energie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Goodbye, silicon? On the way to new electronic materials with metal-organic networks

Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz (Germany) together with scientists from Dresden, Leipzig, Sofia (Bulgaria) and Madrid (Spain) have now developed and characterized a novel, metal-organic material which displays electrical properties mimicking those of highly crystalline silicon. The material which can easily be fabricated at room temperature could serve as a replacement for expensive conventional inorganic materials used in optoelectronics.

Silicon, a so called semiconductor, is currently widely employed for the development of components such as solar cells, LEDs or computer chips. High purity...

Im Focus: Storage & Transport of highly volatile Gases made safer & cheaper by the use of “Kinetic Trapping"

Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles

Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...

Im Focus: Disrupting crystalline order to restore superfluidity

When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.

We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...

Im Focus: Micro energy harvesters for the Internet of Things

Fraunhofer IWS Dresden scientists print electronic layers with polymer ink

Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...

Im Focus: Dynamik einzelner Proteine

Neue Messmethode erlaubt es Forschenden, die Bewegung von Molekülen lange und genau zu verfolgen

Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Conference to pave the way for new therapies

17.10.2018 | Event News

Berlin5GWeek: Private industrial networks and temporary 5G connectivity islands

16.10.2018 | Event News

5th International Conference on Cellular Materials (CellMAT), Scientific Programme online

02.10.2018 | Event News

 
Latest News

RUDN chemist tested a new nanocatalyst for obtaining hydrogen

18.10.2018 | Life Sciences

Massive organism is crashing on our watch

18.10.2018 | Earth Sciences

Electrical enhancement: Engineers speed up electrons in semiconductors

18.10.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>