* Astronomy

Members Login
Post Info TOPIC: NGC 602


L

Posts: 131433
Date:
NGC 602
Permalink  
 


NGC 602 (also ESO 29-SC43 and N90) is a magnitude +13.7 open star cluster and emission nebula located 200,000 light-years away in the Small Magellanic Cloud in the constellation Hydrus.
NGC 602 is a young cluster, whose age is estimated at 5 million years.

The cluster was discovered by Scottish astronomer James Dunlop using a homemade 9-foot 22.86 cm (9 inch) f/12 speculum Newtonian reflector at Paramatta, New South Wales, Australia, on the 1st August 1826.

Right Ascension 01h 29m 25.0s, Declination -73° 33' 30" 

Radiation and shock waves from the stars have pushed away much of the lighter surrounding gas and dust that compose the nebula known as N90, and this in turn has triggered new star formation in the ridges (or "elephant trunks") of the nebula. 
Read more



__________________


L

Posts: 131433
Date:
NGC 602a
Permalink  
 


A Confetti-Like Collection of Stars

738735main_ngc602_665.jpg

It's like a disco wonderland for stars. The tip of the "wing" of the Small Magellanic Cloudgalaxy is dazzling in pink and purples in a new view from NASA's Great Observatories. The Small Magellanic Cloud is a small galaxy about 200,000 light-years away from own Milky Way spiral galaxy. 
The colours represent wavelengths of light across a broad spectrum. X-rays from NASA's Chandra X-ray Observatory are shown in purple; visible-light from NASA's Hubble Space Telescope is coloured red, green and blue; and infrared observations from NASA's Spitzer Space Telescope are also represented in red. 

Read more



__________________


L

Posts: 131433
Date:
RE: NGC 602
Permalink  
 


Title: The clustered nature of star formation. Pre--main-sequence clusters in the star-forming region NGC 602/N90 in the Small Magellanic Cloud
Authors: Dimitrios A. Gouliermis, Stefan Schmeja, Andrew E. Dolphin, Mario Gennaro, Emanuele Tognelli, Pier Giorgio Prada Moroni

Located at the tip of the wing of the Small Magellanic Cloud (SMC), the star-forming region NGC602/N90 is characterised by the HII nebular ring N90 and the young cluster of pre--main-sequence (PMS) and early-type main sequence stars NGC602. We present a thorough cluster analysis of the stellar sample identified with HST/ACS camera in the region. We show that apart from the central cluster, low-mass PMS stars are congregated in thirteen additional small compact sub-clusters at the periphery of NGC602. We find that the spatial distribution of the PMS stars is bimodal, with an unusually large fraction (~60%) of the total population being clustered, while the remaining is diffusely distributed in the inter-cluster area. From the corresponding colour-magnitude diagrams we disentangle an age-difference of ~2.5Myr between NGC602 and the compact sub-clusters which appear younger. The diffuse PMS population appears to host stars as old as those in NGC602. Almost all detected PMS sub-clusters appear to be centrally concentrated. When the complete PMS stellar sample, including both clustered and diffused stars, is considered in our cluster analysis, it appears as a single centrally concentrated stellar agglomeration, covering the whole central area of the region. Considering also the hot massive stars of the system, we find evidence that this agglomeration is hierarchically structured. Based on our findings we propose a scenario, according to which the region NGC602/N90 experiences an active clustered star formation for the last ~5Myr. The central cluster NGC602 was formed first and rapidly started dissolving into its immediate ambient environment, possibly ejecting also massive stars found away from its center. Star formation continued in sub-clusters of a larger stellar agglomeration, introducing an age-spread of the order of 2.5Myr among the PMS populations.

Read more (6492kb, PDF)



__________________


L

Posts: 131433
Date:
Permalink  
 

Title: NGC 602 Environment, Kinematics and Origins
Authors: L. Nigra, J. S. Gallagher III, L. J. Smith, S. Stanimirovic, A. Nota, E. Sabbi

The young star cluster NGC 602 and its associated HII region, N90, formed in a relatively isolated and diffuse environment in the Wing of the Small Magellanic Cloud. Its isolation from other regions of massive star formation and the relatively simple surrounding HI shell structure allows us to constrain the processes that may have led to its formation and to study conditions leading to massive star formation. We use images from Hubble Space Telescope and high resolution echelle spectrographic data from the Anglo-Australian Telescope along with 21-cm neutral hydrogen (HI) spectrum survey data and the shell catalogue derived from it to establish a likely evolutionary scenario leading to the formation of NGC 602. We identify a distinct HI cloud component that is likely the progenitor cloud of the cluster and HII region which probably formed in blister fashion from the cloud's periphery. We also find that the past interaction of HI shells can explain the current location and radial velocity of the nebula. The surrounding Interstellar Medium is diffuse and dust-poor as demonstrated by a low visual optical depth throughout the nebula and an average HI density of the progenitor cloud estimated at 1 cm^-3. These conditions suggest that the NGC 602 star formation event was produced by compression and turbulence associated with HI shell interactions. It therefore represents a single star forming event in a low gas density region.
 
Read more ((3339kb, PDF)

__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard