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Astronomer, outreach coordinator and producer of the monthly news segment of the Jodcast.
Rigel
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- March 4, 2010
- 02:31 AM
- 47 views
In the News this month: emission from methane in the atmosphere of an extrasolar planet
In just fifteen years, have been discovered around stars other than the Sun using a variety of techniques. Even without the ability to directly image these other worlds, some of their properties can be determined. Most extra solar planets found so far are massive orbiting close to their parent stars, since these are the types of planets that the detection methods are most sensitive to. As develop and improve, astronomers are finding out more and more about these other worlds, including the co........ Read more »
Swain, M., Deroo, P., Griffith, C., Tinetti, G., Thatte, A., Vasisht, G., Chen, P., Bouwman, J., Crossfield, I., Angerhausen, D.... (2010) A ground-based near-infrared emission spectrum of the exoplanet HD 189733b. Nature, 463(7281), 637-639. DOI: 10.1038/nature08775
- March 4, 2010
- 01:58 AM
- 48 views
In the News this month: the molecular content of early galaxies
A long-standing question in the study of is whether the process was more efficient in the early universe than it is today. Stars form through the collapse of clouds of cold gas. As the collapse progresses, the of the cloud gets denser and hotter until begins and a star is born. In the local universe, however, cold molecular gas is relatively rare so star formation occurs slowly; the Milky Way forms new stars at a rate of only a few per year. More distant galaxies formed stars at a much higher........ Read more »
Tacconi, L., Genzel, R., Neri, R., Cox, P., Cooper, M., Shapiro, K., Bolatto, A., Bouché, N., Bournaud, F., Burkert, A.... (2010) High molecular gas fractions in normal massive star-forming galaxies in the young Universe. Nature, 463(7282), 781-784. DOI: 10.1038/nature08773
- March 4, 2010
- 01:16 AM
- 45 views
In the News this month: the explosion mechanism behind type Ia supernovae
Supernova explosions are initially by the chemical signatures in their optical spectra. While some are caused by the catastrophic collapse of stars more than eight times as massive as the Sun, others are thought to be caused by , stars like the Sun which have already evolved off the main sequence and shrunk in size. Called Type Ia supernovae, such explosions are thought to have a fixed brightness, allowing them to be used as to measure distances to galaxies and test cosmological models of the ........ Read more »
Gilfanov, M., & Bogdán, A. (2010) An upper limit on the contribution of accreting white dwarfs to the type Ia supernova rate. Nature, 463(7283), 924-925. DOI: 10.1038/nature08685
- February 2, 2010
- 12:02 AM
- 95 views
In the news this month: the coolest brown dwarf yet
An international team, led by astronomers at the University of Hertfordshire have discovered what may be the coolest sub-stellar body ever found outside our own solar system. Using the United Kingdom Infrared Telescope (UKIRT) in Hawaii, the , smaller than other stars but larger than gas giant planets such as Jupiter. The object, known as SDSS1416+13B, is only visible in infra-red light and is in a wide orbit around a somewhat brighter and warmer known as SDSS1416+13A. This discovery is "the fo........ Read more »
Ben Burningham, S. K. Leggett, P. W. Lucas, D. J. Pinfield, R. L. Smart, A. C. Day-Jones, H. R. A. Jones, D. Murray, E. Nickson, M. Tamura.... (2010) The discovery of a very cool binary system. MNRAS. arXiv: 1001.4393v1
- February 1, 2010
- 11:50 PM
- 81 views
In the news this month: coronal loops imaged around another star
Most of our knowledge of the processes and morphology of stellar coronae comes from observing our nearest star, the Sun. Coronal loops are associated with sunspot groups which affect the streams of charged particles leaving the Sun as the solar wind, so an understanding of the processes in these loops has implications for space weather predictions which can impact on satellite operations and the safety of astronauts.Studying the same processes in other stars is difficult due to the distances inv........ Read more »
Peterson, W., Mutel, R., Güdel, M., & Goss, W. (2010) A large coronal loop in the Algol system. Nature, 463(7278), 207-209. DOI: 10.1038/nature08643
- February 1, 2010
- 11:18 PM
- 96 views
In the news this month: Chandra tells tails of extragalactic star formation
Star formation is usually thought of as occurring mainly in the spiral arms of galaxies. In close encounters or collisions between galaxies, the orbits of these stars around the galactic disk can be disrupted, resulting in some stars being thrown out into intergalactic space. But new results from the Chandra X-ray Observatory suggest that, at least in some cases, stars can form outside the normal boundaries of galactic disks.A team led by Ming Sun at the University of Virginia used the orbiting ........ Read more »
Sun, M., Donahue, M., Roediger, E., Nulsen, P., Voit, G., Sarazin, C., Forman, W., & Jones, C. (2010) SPECTACULAR X-RAY TAILS, INTRACLUSTER STAR FORMATION, AND ULXs IN A3627. The Astrophysical Journal, 708(2), 946-964. DOI: 10.1088/0004-637X/708/2/946
- January 27, 2010
- 01:21 PM
- 126 views
Doctor Who and the Silver Spiral
Far across the universe, something big was about to happen. The explosion would outshine an entire galaxy and be visible billions of kilometres away. Its light would travel across the universe for millions of years but, aside from a few astronomers, it would go unnoticed on the Earth.With a grating, wheezing noise, a small blue box flickered into existence."So, where are we?""Have a look..." the Doctor replied, tapping a control, "but... don't step outside."The door of the TARDIS clicked open, a........ Read more »
Paragi, Z., Taylor, G., Kouveliotou, C., Granot, J., Ramirez-Ruiz, E., Bietenholz, M., van der Horst, A., Pidopryhora, Y., van Langevelde, H., Garrett, M.... (2010) A mildly relativistic radio jet from the otherwise normal type Ic supernova 2007gr. Nature, 463(7280), 516-518. DOI: 10.1038/nature08713
Crockett, R., Maund, J., Smartt, S., Mattila, S., Pastorello, A., Smoker, J., Stephens, A., Fynbo, J., Eldridge, J., Danziger, I.... (2008) The Birth Place of the Type Ic Supernova 2007gr. The Astrophysical Journal, 672(2). DOI: 10.1086/527299
Soderberg, A., Chakraborti, S., Pignata, G., Chevalier, R., Chandra, P., Ray, A., Wieringa, M., Copete, A., Chaplin, V., Connaughton, V.... (2010) A relativistic type Ibc supernova without a detected γ-ray burst. Nature, 463(7280), 513-515. DOI: 10.1038/nature08714
- January 3, 2010
- 08:48 PM
- 155 views
In the News this month: first observational evidence of a new type of supernova
Stars the size and mass of our Sun end their lives by first expanding as , then shrinking to . Stars heavier than this however, come to a much more violent end.; For stars with masses between about 10 and 100 times that of the Sun, they continue in the core, until they run out of hydrogen. They then begin to fuse the helium nuclei together to form heavier elements such as carbon, nitrogen and oxygen. This carries on through the elements until iron, at which point the to form either a neutron s........ Read more »
Gal-Yam, A., Mazzali, P., Ofek, E., Nugent, P., Kulkarni, S., Kasliwal, M., Quimby, R., Filippenko, A., Cenko, S., Chornock, R.... (2009) Supernova 2007bi as a pair-instability explosion. Nature, 462(7273), 624-627. DOI: 10.1038/nature08579
- January 3, 2010
- 09:03 AM
- 171 views
In the News this month: the role of magnetic fields in GRBs
are highly energetic explosions which release enormous amounts of energy in just a few seconds. So-called because they were first discovered through their intense gamma-ray emission, these explosions can be seen across the visible universe. The exact nature of the jets which give rise to this emission is however, not certain. Different jet models predict very different properties of the magnetic fields present in the out-flowing material. Some models suggest that weak are present only locally ........ Read more »
Steele, I., Mundell, C., Smith, R., Kobayashi, S., & Guidorzi, C. (2009) Ten per cent polarized optical emission from GRB 090102. Nature, 462(7274), 767-769. DOI: 10.1038/nature08590
- January 3, 2010
- 08:27 AM
- 143 views
In the News this month: stellar canibalism in globular clusters
contain some of the oldest known stars.; Formed billions of years ago in the halos of what eventually become the galaxies we see today, globular clusters are roughly spherical collections of stars bound together by their own gravity. Our own Milky Way contains many such clusters, several of which were catalogued by in the 18th Century.While most of the stars in globular clusters have ages of 12 to 13 billion years, some of them appear to be much younger. Most stars in globular clusters are red........ Read more »
Ferraro, F., Beccari, G., Dalessandro, E., Lanzoni, B., Sills, A., Rood, R., Pecci, F., Karakas, A., Miocchi, P., & Bovinelli, S. (2009) Two distinct sequences of blue straggler stars in the globular cluster M 30. Nature, 462(7276), 1028-1031. DOI: 10.1038/nature08607
Mathieu, R., & Geller, A. (2009) A binary star fraction of 76 per cent and unusual orbit parameters for the blue stragglers of NGC 188. Nature, 462(7276), 1032-1035. DOI: 10.1038/nature08568
- December 2, 2009
- 09:03 AM
- 181 views
In the News this month: spectacular outflows in Orion
The constellation of Orion contains some massive complex regions of star formation, the most obvious of which is the , M42, located in Orion's sword. Through an optical telescope you can see a large glowing cloud of gas illuminated by a cluster of young, hot stars. But behind this cloud, hidden from view, lies another cluster of proto-stars, clumps of gas still collapsing under gravity in the process of forming stars. As ordinary light cannot penetrate through the gas, other parts of the el........ Read more »
L. D. Matthews, L. J. Greenhill, C. Goddi, C. J. Chandler, E. M. L. Humphreys, & M. Kunz. (2010) A Feature Movie of SiO Emission 20-100 AU from the Massive Young Stellar Object Orion Source I. Astrophysical Journal. arXiv: 0911.2473v1
- December 2, 2009
- 08:41 AM
- 183 views
In the News this month: a new way to search for exoplanets
are continuously being refined and are detecting ever smaller planets at greater and greater distances from their parent stars. But a team of astronomers have between planetary systems and lithium abundance that could provide a . Most methods of searching for planetary systems around other stars are best suited to finding large planets orbiting very close to their host stars. But what if there was a way to determine the likelihood of a particular star hosting planets, without actually detectin........ Read more »
Israelian, G., Mena, E., Santos, N., Sousa, S., Mayor, M., Udry, S., Cerdeña, C., Rebolo, R., & Randich, S. (2009) Enhanced lithium depletion in Sun-like stars with orbiting planets. Nature, 462(7270), 189-191. DOI: 10.1038/nature08483
- December 2, 2009
- 08:20 AM
- 165 views
In the News this month: mystery at the centre of Cas A
When massive stars explode as supernovae, they leave behind a dense, compact object: either a neutron star or a black hole depending on the mass of the original star. They also produce an expanding shell of debris known as a supernova remnant. Many of these shells are known in the Milky Way, but compact objects are not detected in all of them. One object in particular, the remnant known as has been expanding since its progenitor star exploded about 330 years ago, but for a long time no compact ........ Read more »
Ho, W., & Heinke, C. (2009) A neutron star with a carbon atmosphere in the Cassiopeia A supernova remnant. Nature, 462(7269), 71-73. DOI: 10.1038/nature08525
- October 31, 2009
- 06:13 AM
- 244 views
In the news this month... another impressive exoplanet haul from HARPS
2009 has been a good year for exoplanets, and one team of astronomers have discovered most of them. Since the first planet was found orbiting a star other than the Sun, many more have been discovered using increasingly sensitive instruments and sophisticated techniques. Because they are so faint compared to their parent stars, most planets are discovered through indirect methods. One of the most successful has been the which uses the principle of the Doppler effect to detect the tiny changes in........ Read more »
Mayor, M.; Pepe, F.; Queloz, D.; Bouchy, F.; Rupprecht, G.; Lo Curto, G.; Avila, G.; Benz, W.; Bertaux, J.-L.; Bonfils, X.; dall, Th.; Dekker, H.; Delabre, B.; Eckert, W.; Fleury, M.; Gilliotte, A.; Gojak, D.; Guzman, J. C.; Kohler, D.; Lizon, J.-L.; Long. (2003) Setting New Standards with HARPS. Messenger, 20-24. info:other/2003Msngr.114..20M
- October 31, 2009
- 05:31 AM
- 292 views
In the news this month... a record-breaking distant cluster
Look deep enough with a sensitive telescope and a seemingly empty patch of sky is full of galaxies. Look closely and you'll see that they are often gathered together in clusters. These massive collections of galaxies are the largest gravitationally bound objects in the universe, but it is uncertain how long ago these clusters formed. Now, using a variety of instruments, a team led by Stefano Andreon of the in Milan, Italy, has the most distant galaxy cluster ever found.The cluster, known as JK........ Read more »
Andreon, S., Maughan, B., Trinchieri, G., & Kurk, J. (2009) JKCS041: a colour-detected galaxy cluster at zphot~1.9 with deep potential well as confirmed by X-ray data. Astronomy and Astrophysics. DOI: 10.1051/0004-6361/200912299
- October 31, 2009
- 04:51 AM
- 246 views
In the news this month... shaping the heliosphere
Solar physicists thought they knew the shape of the Sun's heliosphere, but new results from the have revealed a huge ribbon of intense emission that was completely unexpected. The space between stars is not empty, but filled with a very tenuous gas known as the interstellar medium. As the Sun moves through this gas it emits a fast moving plasma know as the solar wind. These charged particles spread out spherically creating the , a cavity in the interstellar medium swept out by the solar wind.La........ Read more »
McComas, D., Allegrini, F., Bochsler, P., Bzowski, M., Christian, E., Crew, G., DeMajistre, R., Fahr, H., Fichtner, H., Frisch, P.... (2009) Global Observations of the Interstellar Interaction from the Interstellar Boundary Explorer (IBEX). Science. DOI: 10.1126/science.1180906
Funsten, H., Allegrini, F., Crew, G., DeMajistre, R., Frisch, P., Fuselier, S., Gruntman, M., Janzen, P., McComas, D., Mobius, E.... (2009) Structures and Spectral Variations of the Outer Heliosphere in IBEX Energetic Neutral Atom Maps. Science. DOI: 10.1126/science.1180927
Mobius, E., Bochsler, P., Bzowski, M., Crew, G., Funsten, H., Fuselier, S., Ghielmetti, A., Heirtzler, D., Izmodenov, V., Kubiak, M.... (2009) Direct Observations of Interstellar H, He, and O by the Interstellar Boundary Explorer. Science. DOI: 10.1126/science.1180971
Fuselier, S., Allegrini, F., Funsten, H., Ghielmetti, A., Heirtzler, D., Kucharek, H., Lennartsson, O., McComas, D., Mobius, E., Moore, T.... (2009) Width and Variation of the ENA Flux Ribbon Observed by the Interstellar Boundary Explorer. Science. DOI: 10.1126/science.1180981
Schwadron, N., Bzowski, M., Crew, G., Gruntman, M., Fahr, H., Fichtner, H., Frisch, P., Funsten, H., Fuselier, S., Heerikhuisen, J.... (2009) Comparison of Interstellar Boundary Explorer Observations with 3-D Global Heliospheric Models. Science. DOI: 10.1126/science.1180986
Krimigis, S., Mitchell, D., Roelof, E., Hsieh, K., & McComas, D. (2009) Imaging the Interaction of the Heliosphere with the Interstellar Medium from Saturn with Cassini. Science. DOI: 10.1126/science.1181079
- October 5, 2009
- 07:06 AM
- 355 views
In the News this month: first results from a panoramic survey of the Andromeda galaxy
Edwin Hubble's original classification of galaxies into various types based on their visible shapes and structures has been a feature of extra-galactic astronomy since the 1920s. The scheme, originally thought to depict an evolutionary sequence, has two major groups: spiral galaxies with a small central bulge, spiral arms and possibly a central bar, and elliptical galaxies that are more spherical in structure with no spiral arms or disk. There are however, many galaxies which do not fit into thi........ Read more »
McConnachie, A., Irwin, M., Ibata, R., Dubinski, J., Widrow, L., Martin, N., Côté, P., Dotter, A., Navarro, J., Ferguson, A.... (2009) The remnants of galaxy formation from a panoramic survey of the region around M31. Nature, 461(7260), 66-69. DOI: 10.1038/nature08327
- October 5, 2009
- 06:50 AM
- 324 views
In the News this month: discovery of water on the Moon
It is thought that the Moon was formed about four and a half billion years ago by the collision of a Mars-sized object with the Earth. The heat from the impact and subsequent accretion of material created a magma ocean which would have caused the loss of most of the volatile materials from the surface, so-called because they have low boiling points and evaporate easily. In a press conference at NASA on Thursday 24th September, results were announced from three separate spacecraft showing eviden........ Read more »
Sunshine, J., Farnham, T., Feaga, L., Groussin, O., Merlin, F., Milliken, R., & A'Hearn, M. (2009) Temporal and Spatial Variability of Lunar Hydration as Observed by the Deep Impact Spacecraft. Science. DOI: 10.1126/science.1179788
Pieters, C., Goswami, J., Clark, R., Annadurai, M., Boardman, J., Buratti, B., Combe, J., Dyar, M., Green, R., Head, J.... (2009) Character and Spatial Distribution of OH/H2O on the Surface of the Moon Seen by M3 on Chandrayaan-1. Science. DOI: 10.1126/science.1178658
Clark, R. (2009) Detection of Adsorbed Water and Hydroxyl on the Moon. Science. DOI: 10.1126/science.1178105
- October 5, 2009
- 06:21 AM
- 268 views
In the News this month: first evidence of a solid exoplanet
Using various techniques, astronomers have, over the last decade, discovered many hundreds of planets outside our own solar system. Most of these techniques are indirect because planets are much fainter than the stars they orbit, and so are very hard to detect directly. Because their effects are easier to spot, larger planets are easier to find, but smaller and smaller planets are being discovered as techniques and technology improve. One of the smallest exoplanets known to date is CoRoT-7b, a p........ Read more »
Queloz, D., Bouchy, F., Moutou, C., Hatzes, A., Hebrard, G., Alonso, R., Auvergne, M., Baglin, A., Barbieri, M., Barge, P.... (2009) The CoRoT-7 planetary system: two orbiting super-Earths. Astronomy and Astrophysics. DOI: 10.1051/0004-6361/200913096
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