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 Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

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: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

Construction of practical quantum computers radically simplified

05.12.2016 | Information Technology

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>