ISS above London is back

August 31, 2010 21:21 by scibuff

After a short stay in Amsterdam my photo equipment is back in London snapping photos of ISS fly-overs whenever the weather permits. Here’s a stacked composite of the International Space Station (ISS) pass over London at 20:30 UTC tonight.

ISS fly over London

ISS fly over London with 2 minutes worth of star trails from the "zodiac" constellation of Ophiuchus. The bright star to the right of the ISS trail is Arcturus - Canon 450D, 20x5s f/4.5 ISO 400

Click on the the photo to see more details and star trails.

Sky chart for ISS fly over London

Sky chart for ISS fly over London - Tuesday, August 31, 2010 - 20:31:57 - 20:35:56 UTC - Source: Heavens-Above.com

For more information about (visible) passes of ISS, and satellites, not only in London but for any place on Earth, visit the heavens above website. You can also follow @twisst, @abovelondon and @abovesf (if you’re in the San Francisco area) on twitter.

ISS groundtrack

The ground track of ISS with its current position - The dashed part of the orbit path shows where the satellite is in the earth's shadow, and the full part is where it is sunlit - Source: Heavens-Above.com

Rosette Baby Boom

April 12, 2010 14:48 by scibuff

The latest image of the Rosette Nebula taken by the Herschel Space Observatory reveals previously unseen stars with up to ten times the mass of our Sun. The image is a combination of three different wavelength from the infrared part of spectrum: at 70 microns (blue), 160 microns (green) and 250 microns (red. The raw data was acquired by Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE).

The Rosette molecular cloud, seen by Herschel

Infrared image of the Rosette molecular cloud in a three-colour composite made with observations from Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE) - Credit: ESA/PACS & SPIRE Consortium/HOBYS Key Programme Consortia

The Rosette Nebula is located about 5,200 light years from Earth and is associated with a larger cloud that contains enough dust and gas to make the equivalent of 10,000 Sun-like stars. The Herschel image shows half of the nebula and most of the Rosette cloud. The massive stars powering the nebula lie to the right of the image but are invisible at these wavelengths. Each color represents a different temperature of dust, from –263ºC (only 10ºC above absolute zero) in the red emission to –233ºC in the blue.

The small spots near the center and in the redder regions of the image are lower mass protostars, similar in mass to the Sun. The bright smudges are dusty cocoons hiding massive protostars. These will eventually become stars containing around ten times the mass of the Sun and will significantly influence the formation of the next generation of stars.  The understanding of the formation of high-mass stars in our Galaxy is important because they feed so much light and other forms of energy into their parent cloud they can often trigger the formation of the next generation of stars.

Source: ESA

Filaments of cold dust stretching through our Galaxy

March 17, 2010 13:06 by scibuff

Giant filaments of cold dust stretching through our Galaxy are revealed in a new image from ESA’s Planck satellite. Analysing these structures could help to determine the forces that shape our Galaxy and trigger star formation.

Planck sees tapestry of cold dust

The image spans about 50° of the sky. It is a three-colour combination constructed from Planck’s two highest frequency channels (557 and 857 GHz, corresponding to wavelengths of 540 and 350 micrometres), and an image at the shorter wavelength of 100 micrometres made by the IRAS satellite. This combination visualises dust temperature very effectively: red corresponds to temperatures as cold as 10° above absolute zero, and white to those of a few tens of degrees. Overall, the image shows local dust structures within 500 light-years of the Sun - Credit: ESA/HFI Consortium/IRAS

The image shows the filamentary structure of dust in the solar neighborhood – within about 500 light-years of the Sun. The local filaments are connected to the Milky Way, which is the pink horizontal feature near the bottom of the image.

What makes these structures have these particular shapes is not well understood,” says Jan Tauber, ESA Project Scientist for Planck. The denser parts are called molecular clouds while the more diffuse parts are ‘cirrus’. They consist of both dust and gas, although the gas does not show up directly in this image.

There are many forces at work in the Galaxy to help shape the molecular clouds and cirrus into these filamentary patterns. For example, on large scales the Galaxy rotates, creating spiral patterns of stars, dust, and gas. Gravity exerts an important influence, pulling on the dust and gas. Radiation and particle jets from stars push the dust and gas around, and magnetic fields also play a role, although to what extent is presently unclear.

Bright spots in the image are dense clumps of matter where star formation may take place. As the clumps shrink, they become denser and better at shielding their interiors from light and other radiation. This allows them to cool more easily and collapse faster.

ESA’s Herschel space telescope can be used to study such regions in detail, but only Planck can find them all over the sky. Launched together in May 2009, Planck and Herschel are both studying the coolest components of the Universe. Planck looks at large structures, while Herschel can make detailed observations of smaller structures, such as nearby star-forming regions.

Source: ESA

For latest updates from the Herschel/Planck mission follow ESAHerschel and HerschelPlanck on twitter.

Phobos Flyby Images

March 15, 2010 11:45 by scibuff

ESA’s Mars Express spacecraft, while executing a series of 12 flybys of Mars’ largest moon Phobos, passed the moon’s surface at an altitude of 67km on March 3 at 20:55 GMT. The close approach enabled scientists to gain valuable data an learn more about the mysterious moon.

Another flyby close of Phobos occurred on 7 March 2010, and ESA has just released the photos. The images show Mars’ rocky moon in exquisite detail, with a resolution of just 4.4 meters per pixel. They show the proposed landing sites for the forthcoming Phobos-Grunt mission.

Phobos from up close

The High Resolution Stereo Camera (HRSC) onboard the ESA spacecraft Mars Express took this image of Phobos using the HRSC nadir channel on 7 March 2010, HRSC Orbit 7915. This image has additionally been enhanced photometrically for better bringing features in the less illuminated part. Resolution: about 4.4 meters per pixel - Credit: ESA/DLR/FU Berlin (G. Neukum)

In 2011 Russia will send a mission called Phobos–Grunt (meaning Phobos Soil) to land on the martian moon, collect a soil sample and return it to Earth for analysis.

For operational and landing safety reasons, the proposed landing sites were selected on the far side of Phobos. This region was imaged by the HRSC high-resolution camera of Mars Express during the July-August 2008 flybys of Phobos. But new HRSC images showing the vicinity of the landing area under different conditions, such as better illumination from the Sun, remain highly valuable for mission planners.

Phobos Grunt landing areas

The High Resolution Stereo Camera (HRSC) onboard the ESA spacecraft Mars Express took this image of the Phobos Grunt landing area using the HRSC nadir channel on 7 March 2010, HRSC Orbit 7915. The image resolution is 4.4m per pixel and the insert marks the proposed landing region and sites for Phobos-Grunt - Credit: ESA/DLR/FU Berlin (G. Neukum)

Source: ESA

Mars Express heading for closest flyby of Phobos

March 1, 2010 15:39 by scibuff

ESA’s Mars Express spacecraft, currently executing a series of 12 flybys of Mars’ largest moon Phobos, will pass the moon’s surface at an altitude of 67km on March 3 at 20:55 GMT. The close approach will enable scientists to gain valuable data an learn more about the mysterious moon.

Mars’ moon Phobos

This image was obtained by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express on 28 July 2008 (orbit 5870), at a distance of 351 km from the moon’s centre - Credit: ESA/ DLR/ FU Berlin (G. Neukum)

As the spacecraft approaches Phobos, it will be pulled slightly off of its orbit (by a few millimeters per second). Scientists on Earth will turn off all data signals from the spacecraft ensuring the only thing affecting the signal is gravitational tug by Phobos. Although incredible tiny (only one part in a trillion, that is 1 followed by 12 zeros), the changes will be revealed via the Doppler effect.

Animation revealing the graviational influance of Phobos on the orbit or Mars Express - Credit: MaRS team/Observatoire Royal de Belgique

This animation shows how the orbit of Mars Express has been influenced by the gravitational influence of Phobos during the spacecrafts fly-bys of the moon in Summer 2008. Since the orbital deviation strictly depends on the mass and shape of the moon, scientists could use this very deviation to determine the mass of Phobos with unprecedented accuracy (to about one billionth the mass of the Earth).

Magnificent VLT image of the giant stellar nursery surrounding NGC 3603

February 3, 2010 11:37 by scibuff

The European South Observatory (ESO) has released this magnificent image of the giant stellar nursery surrounding NGC 3603 taken at the Very Large Telescope (VLT) facility in Chile. NGC 3603 is an open cluster of stars situated in the Carina spiral arm of the Milky Way around 20,000 light-years away from our solar system. It was discovered by John Frederick William Herschel in 1834.

NGC 3603 starburst region

NGC 3603 is a starburst region: a cosmic factory where stars form frantically from the nebula’s extended clouds of gas and dust - Credit: ESA

[High-res version]

The central cluster of stars inside NGC 3603 harbors thousands of stars of all sorts: the majority have masses similar to or less than that of our Sun, but most spectacular are several of the very massive stars that are close to the end of their lives. One star in NGC 3603, namely Sher 25, was found to have thrown off matter in a pattern similar to that found for the supernova 1987A.

NGC 3603 was selected at the best target to investigate collective, massive star formation, in particular the coalescence of high- and low-mass stars in the violent environments of starburst regions. NGC 3603 is the only massive, galactic HII-region in which a central cluster of strongly UV-radiating stars of types “O” and “B” that ionize the nebula can be studied at visual and near-infrared wavelengths. Because of NGC3603′s location relative to Earth, the line-of-sight to the cluster is relatively free of interstellar dust that dims the near-infrared radiation due to matter interaction. Because enough infrared (IR) light reaches the Earth, the Infrared Spectrometer And Array Camera (ISAAC) at VLT can study the densest part of the cluster resolvable only in very sensitive IR instruments.

NGC 3603

These images of the NGC 3603 region were obtained in three near-IR filter bands (Js, H and Ks) with the ISAAC instrument at the ANTU telescope at the VLT at Paranal - Credit: ESO

[High-res version]

Previously, an international group of astronomers used the ESO Very Large Telescope to perform unique observations of an interstellar nebula in which stars are currently being born. Thanks to the excellent imaging properties of the first of the four 8.2-m VLT Unit Telescopes, ANTU, they were able to demonstrate, for the first time, the presence of large numbers of small and relatively light, new-born stars in NGC 3603.

Source – ESO: The Stars behind the Curtain & Lots of Small Stars Born in Starburst Region