Stellar Nurseries Research Articles

Coronae in theCoronet: a very deep X-ray look into a stellar nursery

Aims. To study the X-ray properties of young stellar objects (YSOs), we analyze an exceptionally sensitive Chandra dataset of the Coronet cluster in the CrA star-forming region, achieving a limiting luminosity of L X,min ∼ 5 × 10 26 erg/s for lightly absorbed sources. This dataset represents one of the most sensitive X-ray observations ever obtained of a star-forming region. Methods. The X-ray data are used to investigate the membership status of tentative members of the region, to derive plasma temperatures and X-ray luminosities of the YSOs, and to investigate variability on the timescale of several years. Results. 46 of the 92 X-ray sources in the merged Chandra image can be identified with optical or near/mid-infrared counterparts. X-ray emission is detected from all of the previously known optically visible late-type (spectral types G to M) stellar cluster members, from five of the eight brown dwarf candidates, and from nine embedded objects (protostars) with class 0, class I, or flat-spectrum spectral-energy distributions (SEDs) in the field of view. While the Herbig Ae/Be stars TY CrA and R CrA, a close companion of the B9e star HD 176386, and the FOe star T CrA are detected, no X-ray emission is found from any of the Herbig-Haro (HH) objects or the protostellar cores without infrared source. We find indications for diffuse X-ray emission near R CrA / IRS 7. Conclusions. The observed X-ray properties of the Coronet YSOs are consistent with coronal activity; soft spectral components hinting towards X-ray emission from accretion shocks were not found. The X-ray emission of the AeBe stars TY CrA and HD 176386 probably originates from close late-type companions. The Ae star R CrA shows a peculiar X-ray spectrum and an extremely hot plasma temperature. Finally, we discuss the differences of the X-ray properties of YSOs in different evolutionary stages.

A long time ago, in a galaxy not so far away

Vast stellar nurseries, clouds that dwarf the Solar System and lurking swarms of black holes. Jeff Kanipe probes the unfolding mysteries at the heart of the Milky Way. Astronomers are now pretty sure that there is a massive black hole at the centre of our Galaxy. In a News Feature, Jeff Kanipe reports on the many observational and theoretical strands that are coming together to give a detailed picture of the area around Sagittarius A*, nearest known object to the Galactic Centre. See the roll-fold facing page 600 for the full picture.

A Surprising Stellar Nursery

CAMBRIDGE, MASSACHUSETTS-- By sharpening their view of the Milky Way9s core, astronomers have deduced that stars can arise close to the giant black hole there. (Read more.)

Astronomical observations from Antarctica trace large-scale magnetic fields in stellar nurseries

Astronomical observations from Antarctica trace large-scale magnetic fields in stellar nurseries

Peering into a disrupted stellar nursery

Science NewsVolume 167, Issue 24 p. 372-372 This Week Peering into a disrupted stellar nursery Ron Cowen, Ron CowenSearch for more papers by this author Ron Cowen, Ron CowenSearch for more papers by this author First published: 25 September 2009 https://doi.org/10.1002/scin.5591672405Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume167, Issue2411 June 2005Pages 372-372 RelatedInformation

Life, the universe, and everything

The author Douglas Adams once described the Earth as an “insignificant little blue-green planet” orbiting a “small unregarded yellow sun”. 1 Adams D The hitchhiker's guide to the galaxy. Pan Macmillan, London, UK1979 Google Scholar Our star is not essentially spectacular, but it is also not particularly unique. There are many spiral galaxies similar to the Milky Way, all with a range of different star types, including many similar to our own. The creation of such stars can be seen by looking further and further out at star-forming regions (nebulae). One spectacular star-forming region is the Orion nebula. Easily visible to the naked eye as a fuzzy spot in the Orion constellation, the nebula is roughly 1500 light years from us, and the closest stellar nursery. Near impenetrable at visible wavelengths due to the clouds of gas and dust from which the young stars are forming, the nebula's energetic heart can be viewed easily at X-ray wavelengths.

The Orion Nebula: where stars are born

The glowing cloud in Orion's sword, the Orion Nebula, is a thing of beauty in the night sky; it is also the closest centre of massive star formation - a stellar nursery that reproduces the conditions in which our own Sun formed some 4.5 billion years ago. The study of the Orion Nebula, focused upon by ever more powerful telescopes from Galileo's time to our own, clarifies how stars are formed, and how we have come to understand the process. C. Robert O'Dell has spent a lifetime studying Orion and in this book he explains what the Nebula is, how it shines, its role in giving birth to star and the insights it affords into how common (or rare) planet formation might be. An account of astronomy's extended engagement with one remarkable celestial object, this book also tells the story of astronomy over the last four centuries. To help readers appreciate the Nebula and its secrets, O'Dell unfolds his tale chronologically, as astrophysical knowledge developed, and our knowledge of the Nebula and the night sky improved. Because he served as chief scientist for the Hubble Space Telescope, O'Dell conveys a sense of continuity with his professional ancestors as he describes the construction of the world's most powerful observatory. The result is a rare insider's view of this observatory - and, from that perspective, an intimate observer's understanding of one of the sky's most instructive and magnificent objects.

Unveiling the hidden universe: Infrared observatory clears up dusty tales

p eek in any apartment window, it's said, and you'll discover a unique story. The same is true of the heavens, except that skywatchers face a special challenge. The windows through which they view the cosmos are often clouded by dust. An observer peering through a telescope in visible or ultraviolet light misses much of the drama in the universe, from a stellar nursery teeming with newborns to the fireworks generated by the collision of two galaxies. Infrared telescopes can penetrate this dust, revealing much more of the story. They can also record emissions from heavenly bodies too cool to radiate light at shorter wavelengths and higher energies. For 28 months, the European Space Agency's Infrared Space Observatory (ISO) has scanned the heavens from its vantage point in Earth's orbit. The mission, which ended in early April, generated remarkable new views of several familiar objects. It also examined the composition of these bodies by analyzing the intensity of light at wavelengths from 3 to 240 micrometers. Such a feat isn't possible with ground-based telescopes, which are hampered by water vapor and other molecules in Earth's atmosphere that both emit and absorb infrared light. ISO scientists presented a roundup of the observatory's discoveries last month at a press briefing in London. Some of the most intriguing finds came relatively late in the mission, when the observatory examined a region of Orion, the nearest birthplace of massive stars.

Radio Emission fromROSAT‐discovered Young Stars in and around Taurus‐Auriga

An 8.4 GHz VLA survey of 91 recently discovered lithium-rich late-type stars from the ROSAT All-Sky Survey and pointed observations is presented. These objects lie in the vicinity of the Taurus-Auriga star-forming region (d 140 pc); however, some are dispersed nearly 30° from known active star-forming cloud cores. This sample represents a spatially complete, flux-limited population of X-ray-bright young stars both within and away from the primary Tau-Aur stellar nurseries. Of the 91 sources, 29 are detected in this radio survey with a sensitivity limit of ~0.15 mJy. If they are at the distance of the star-forming clouds, we find that 32% of widely distributed young stars with LX ≥ 5 × 1028 ergs s-1 have radio luminosity densities in excess of 3.5 × 1015 ergs s-1 Hz-1. This detection rate, the ranges of radio and X-ray luminosities, and the LR/LX ratios are consistent with known young weak-lined T Tauri stars (ages ~106 yr) that reside within the Taurus molecular clouds, but they are considerably higher than a zero-age main-sequence population such as the Pleiades (age 7 × 107 yr). The radio properties thus support the pre-main-sequence classification of the stars. They fitted well among other active young stars on the empirical LR versus LX diagram, implying that solar-type gyrosynchrotron activity is the radio emission mechanism.

On "A New Stellar Nursery in the Southern Cross" [Astron.J.112,693(1996)

view Abstract Citations (13) References (27) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On "A New Stellar Nursery in the Southern Cross" [Astron.J.112,693(1996)] Feigelson, Eric D. ; Lawson, Warrick A. Abstract We report spectroscopic observations of the optical counterparts of ROSAT sources proposed by Park & Finley (1996) to be weak-lined T Tauri (WTT) stars in a new star-forming cloud in Crux. We confirm that most are young late-type stars without significant lithium depletion, but do not concur with Park & Finley that they were formed in an uncataloged cloud associated with a ridge seen in IRAS maps. We discuss several possible origins of these stars. Although they may be field ZAMS stars or have formed in the nearby Coalsack, they are most likely representative of the G- and K-type population in the Sco-Cen OB association. At an age of =~ 11 Myr, the Crux ROSAT stars are likely to be examples of intermediate-aged magnetically-active WTT stars which are deficient from most T Tauri star samples. Publication: The Astronomical Journal Pub Date: June 1997 DOI: 10.1086/118424 Bibcode: 1997AJ....113.2130F full text sources ADS | data products SIMBAD (6)

Brown Dwarfs: A Possible Missing Link Between Stars and Planets

Brown dwarfs are objects with masses between that of stars and planets. Postulated some three decades ago, they remained elusive until recently. Unlike stars, these objects have no sustained energy source and cool as they age. One such cool brown dwarf has been discovered as a companion to a nearby star. The spectrum of this object is similar to that of Jupiter. Single brown dwarfs have been detected in stellar nurseries. Ongoing and planned efforts, from both ground and space, will enable astronomers to decisively determine the population of these elusive and dim objects.

Dazzling images from Hubble Space Telescope

The National Aeronautics & Space Administration last week released a gallery of spectacular images from the revamped Hubble Space Telescope. In the upper left photo, a giant ring of gas surrounds the area where supernova 1987A exploded. In the spectrographic images, each color represents a different element: oxygen (single green ring), nitrogen and hydrogen (triple orange rings), and sulfur (double red rings). The brightness of the component rings is correlated with the concentration of the gases. The spectrographic data in the far left image record the characteristic motion of stars and gas in the center of the galaxy as they are hurled around a black hole 300 million times the mass of the sun. The bottom photos show the Orion nebula, a huge cloud of dust and molecules that houses a stellar nursery. The left-hand portion of the image shows a portion of the nebula in visible light. The right-hand ...

A New Stellar Nursery in the Southern Cross

A New Stellar Nursery in the Southern Cross

New Hubble Camera Finds Many Protoplanetary Disks in Orion Nebula

The Orion nebula, a glowing gas cloud studded with brilliant young stars, was discovered in the sword of Orion by Nicolas Fabri de Peiresc just one year after Galileo first looked at the night sky through a telescope. Ever since then, astronomers have hastened to train every new kind of instrument on this spectacular stellar nursery. So that's what NASA did last December, just after the second‐generation Wide Field‐Planetary Camera was put aboard the Hubble Space Telescope by visiting astronauts. (See PHYSICS TODAY, March, page 42.) Outfitted with corrective optics designed to compensate for the much‐lamented flaw in Hubble's primary mirror, the new camera was promptly pointed at a portion of the Orion nebula that its predecessor had imaged two years earlier.

Hubble looks at a stellar nursery

Hubble looks at a stellar nursery

Peering into Orion Nebula's Stellar Nursery

Peering into Orion Nebula's Stellar Nursery