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California Institute of Tehnology
Vision for Space Exploration

   
Novi izgled poznate ljepotice

Ova kompozitna slika uspoređuje dobro pozntu optičku sliku sjajne maglice Trifid (lijevo) s infracrvenim prikazom načinjenim NASA-inim Svemirskim teleskopom Spitzer (tri slike na desnoj strani). Maglica Trifid je divovski oblak plina i prašine u kojemu nastaju nove zvijezde, a koji se nalazi u zviježđu Strijelca, na udaljenosti od 5400 svjetlosnih godina.

Spitzerova slika lažnih boja otkriva jednu drugu stranu maglice Trifid. Na mjestu gdje na optičkoj slici tamne pruge prašine presjecaju maglicu u tri dijela, na Spitzerovim se slikama vide sjajne rađaonice zvijezda. Spitzer je u maglici Trifid otkrio ukupno 30 masivnih zvjezdanih zametaka i 120 manjih novorođenih zvijezda, i u tamnim prugama i u sjajnim oblacima. Te su zvijezde vidljive na svim Spitzerovim slikama, pretežno kao žute ili crvene točke. Zvjezdani embriji su zvijezde u nastanku, koje se svakog časa trebaju poroditi. Deset od trideset masivnih zametaka koje je otkrio Spitzer, nalaze se u četiri tamne jezgre - stelarnim "inkubatorima" u kojima se rađaju zvijezde. Koristeći podatke dobivene milimetarskim teleskopom španjolskog Instituta za radio-astronomiju, astronomi su već ranije bili uočili te jezgre, no smatrali su da one još nisu posve zrele za zvijezde. Spitzerove iznimno osjetljive infracrvene oči bile su u stanju prodrijeti u sve četiri jezgre kako bi otkrili zametke koji brzo rastu.

Pomnim pregledom Spitzerove slike načinjene njegovom IRAC-om (desno gore), astronomi su uspjeli izbrojiti pojedine embrije usađene u te jezgre. IRAC ima najveću prostornu razlučivost od svih Spitzerovih kamera. Spitzerova slika načinjena MIPS-om (desno dolje), s druge strane, posvećena je uočavanju hladnijih materijala. Na njoj se ističe razmjerno hladni materijal jezgre koji upada na rastuće embrije u Trifidu. Slika u sredini je kombinacija Spitzerovih podataka dobivenih obama instrumentima.

Drži se da su ti embriji začeti utjecajem jedne masivne zvijezde tipa O, koja se na sve četiri slike može vidjeti kao bijela mrljica u središtu maglice. Zvijezde tipa O su najmasivnije zvijezde, koje svoje kratke živote završavaju eksplozijom supernove. Male novorođene zvijezde su vjerojatno nastale u isto vrijeme kada i ta O-zvijezda, iz istog oblaka plina i prašine.

Slika snimljena Spitzerovom IRAC-om je trobojni kompozit nevidljive svjetlosti, koji prikazuje emisiju valnih duljina od 3,6 mikrona (plava boja), 4,5 mikrona (zelena boja) i 8 mikrona (crvena boja). Slika Spitzerovog MIPS-a prikazuje emisiju pri 24 mikrona. Spitzerova mozaična slika udružuje podatke s tih dviju slika, tako da je svjetlo pri 4,5 mikrona prikazano plavom bojom, ono pri 8,0 mikrona zelenom, a ono pri 24 mikrona crvenom bojom. Slika u vidljivoj svjetlosti je načinjena teleskopom Nacionalne optičke zvjezdarnice (NOAO) u Tucsonu (SAD).

ANIMACIJA
NASA/JPL-Caltech/R. Hurt (SSC-Caltech)



New Views of a Familiar Beauty

This image composite compares the well-known visible-light picture of the glowing Trifid Nebula (left panel) with infrared views from NASA's Spitzer Space Telescope (remaining three panels). The Trifid Nebula is a giant star-forming cloud of gas and dust located 5,400 light-years away in the constellation Sagittarius.

The false-color Spitzer images reveal a different side of the Trifid Nebula. Where dark lanes of dust are visible trisecting the nebula in the visible-light picture, bright regions of star-forming activity are seen in the Spitzer pictures. All together, Spitzer uncovered 30 massive embryonic stars and 120 smaller newborn stars throughout the Trifid Nebula, in both its dark lanes and luminous clouds. These stars are visible in all the Spitzer images, mainly as yellow or red spots. Embryonic stars are developing stars about to burst into existence. Ten of the 30 massive embryos discovered by Spitzer were found in four dark cores, or stellar "incubators," where stars are born. Astronomers using data from the Institute of Radioastronomy millimeter telescope in Spain had previously identified these cores but thought they were not quite ripe for stars. Spitzer's highly sensitive infrared eyes were able to penetrate all four cores to reveal rapidly growing embryos.

Astronomers can actually count the individual embryos tucked inside the cores by looking closely at the Spitzer image taken by its infrared array camera (top right). This instrument has the highest spatial resolution of Spitzer's imaging cameras. The Spitzer image from the multiband imaging photometer (bottom right), on the other hand, specializes in detecting cooler materials. Its view highlights the relatively cool core material falling onto the Trifid's growing embryos. The middle panel is a combination of Spitzer data from both of these instruments.

The embryos are thought to have been triggered by a massive "type O" star, which can be seen as a white spot at the center of the nebula in all four images. Type O stars are the most massive stars, ending their brief lives in explosive supernovas. The small newborn stars probably arose at the same time as the O star, and from the same original cloud of gas and dust.

The Spitzer infrared array camera image is a three-color composite of invisible light, showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 and 8.0 microns (red). The Spitzer multiband imaging photometer image shows 24-micron emissions. The Spitzer mosaic image combines data from these pictures, showing light of 4.5 microns (blue), 8.0 microns (green) and 24 microns (red). The visible-light image is from the National Optical Astronomy Observatory, Tucson, Ariz.

About the Object
Object Name: Messier 20 - Trifid Nebula
Object Type: Nebula
Position (J2000): RA: 18h02m23.4s Dec: -23d01m50.1s
Distance: 5,500 light-years or 1.67 kpc
Constellation: Sagittarius
About the Data
Image Credit:
NASA/JPL-Caltech/J.Rho(SSC/Caltech)
Instrument: IRAC, MIPS
Wavelength:
IRAC: 3.6, 4.5, 5.8, and 8.0 microns
MIPS: 24 microns
Exposure Date:
IRAC: 2004-03-31
MIPS: 2004-04-11
Exposure Time:
IRAC: 8 sec per sky position
MIPS: 48sec per sky position
Image Scale: about 20 x 25 arcmin
Orientation:
Release Date: 12 January 2005
Observers
J. Rho - Principal Investigator (Spitzer Science Center/Caltech)
W. T. Reach (Spitzer Science Center/Caltech)
B. Lefloch (Laboratoire d'Astrophysique, Observatoire de Grenoble)
G. Fazio (Harvard-Smithsonian Center for Astrophysics)