Astronomy, Facts and figure, Knowledge

Astronomy,Knowledge,Space

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it one of the most massive stars known. This star is the brightest object located just above the gas front in the featured image. Close inspection of images taken with the Hubble Space Telescope, however, have shown that Pismis 24-1 derives its brilliant luminosity not from a single star but from three at least. Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. Toward the bottom of the image, stars are still forming in the associated emission neb

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ula NGC 6357. Appearing perhaps like a Gothic cathedral, energetic stars near the center appear to be breaking out and illuminating a spectacular cocoon.

Prof.Rajeev Tripathi

Astronomy

Conservation of Energy

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Astronomy

Watch “INTRODUCTION by Prof. Rajeev Tripathi” on YouTube

INTRODUCTION by Prof. Rajeev Tripathi: https://youtu.be/uvzL25ncRH8

Astronomy

Watch “INTRODUCTION by Prof. Rajeev Tripathi” on YouTube

INTRODUCTION by Prof. Rajeev Tripathi: http://youtu.be/uvzL25ncRH8

Astronomy

Astronomy

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What strange world is this? Earth. In the foreground of the featured image are the Pinnacles, unusual rock spires in Nambung National Park in Western Australia. Made of ancient sea shells (limestone), how these human-sized picturesque spires formed remains unknown. In the background, just past the end of the central Pinnacle, is a bright crescent Moon. The eerie glow around the Moon is mostly zodiacal light, sunlight reflected by dust grains orbiting between the planets in the Solar System. Arching across the top is the central band of our Milky Way Galaxy. Many famous stars and nebula are also visible in the background night sky. The featured 29-panel panorama was taken and composed last September after detailed planning that involved the Moon, the rock spires, and their corresponding shadows. Even so, the strong zodiacal light was a pleasant surprise.

Astronomy

Astronomy

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In this #cosmic snapshot, the spectacularly #symmetrical wings of #Hen 2-437 show up in a #magnificent icy blue hue. Hen 2-437 is a planetary nebula, one of around 3,000 such objects known to reside within the Milky Way.

Located within the faint northern #constellation of Vulpecula (The Fox), Hen 2-437 was first identified in 1946 by Rudolph Minkowski, who later also discovered the famous and equally #beautiful M2-9 (otherwise known as the Twin Jet Nebula). Hen 2-437 was added to a catalog of planetary nebula over two decades later by astronomer and NASA astronaut Karl Gordon Henize.

Planetary #nebulae such as Hen 2-437 form when an aging low-mass star — such as the sun — reaches the final stages of life. The star swells to become a red #giant, before casting off its #gaseous outer layers into space. The star itself then slowly shrinks to form a white dwarf, while the expelled gas is slowly compressed and pushed outwards by #stellar winds. As shown by its remarkably beautiful appearance, Hen 2-437 is a bipolar #nebula — the material ejected by the dying star has streamed out into #space to create the two #icy blue lobes pictured here.

Astronomy

Tutorial

https://plus.google.com/116952840782221197540/posts/cxGpTD2ub9D?_utm_source=1-2-2

Astronomy

Astronomy

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#Massive #stars lie within NGC 6357, an expansive emission nebula complex some 6,500 light-years away toward the #tail of the constellation Scorpius. In fact, positioned near center in this ground-based close-up of NGC 6357, star cluster Pismis 24 includes some of the most massive stars known in the #galaxy, stars with nearly 100 times the mass of the Sun. The nebula’s bright central region also contains dusty pillars of molecular gas, likely hiding massive protostars from the prying eyes of optical #instruments. Intricate shapes in the nebula are carved as interstellar winds and energetic radiation from the young and newly forming massive stars clear out the natal gas and dust and power the nebular glow. Enhancing the #nebula’s cavernous appearance, narrowband image data was included in this composite color image in a #Hubble palette scheme. #Emission from sulfur, hydrogen, and oxygen atoms is shown in red green and #blue hues. The alluring telescopic view spans about 50 light-years at the estimated distance of NGC 6357.

Astronomy

Astronomy

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The subject of this #NASA/ESA Hubble Space Telescope image is known as NGC 3597. It is the product of a #collision between two good-sized galaxies, and is slowly evolving to become a giant elliptical #galaxy. This type of galaxy has grown more and more common as the #universe has evolved, with initially small galaxies merging and progressively building up into larger galactic structures over time.

NGC 3597 is located approximately 150 million light-years away in the constellation of Crater (The Cup). #Astronomers study NGC 3597 to learn more about how elliptical galaxies form ‘” many ellipticals began their lives far earlier in the history of the #universe. Older ellipticals are nicknamed ‘red and dead’ by astronomers because these bloated galaxies are not anymore producing new, bluer stars, and are thus packed full of old and redder #stellar populations.

Before infirmity sets in, some freshly formed #elliptical galaxies experience a final flush of youth, as is the case with NGC 3597. Galaxies smashing together pool their available gas and #dust, triggering new rounds of star birth. Some of this material ends up in dense pockets initially called proto-globular clusters, dozens of which festoon NGC 3597. These pockets will go on to collapse and form fully-fledged globular #clusters, large spheres that orbit the centers of galaxies like satellites, packed tightly full of millions of stars.

#Hubble #Space #Telescope

Posted by Stephen Hawking/Prof.Rajeev Tripathi

Astronomy, Facts and figure, Knowledge, Science

Astronomy

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Cosmic dust clouds ripple across this infrared portrait of our Milky Way’s satellite galaxy, the Large Magellanic Cloud. In fact, the remarkable composite image from the Herschel Space Observatory and the Spitzer Space Telescope show that dust clouds fill this neighboring dwarf galaxy, much like dust along the plane of the Milky Way itself. The dust temperatures tend to trace star forming activity. Spitzer data in blue hues indicate warm dust heated by young stars. Herschel’s instruments contributed the image data shown in red and green, revealing dust emission from cooler and intermediate regions where star formation is just beginning or has stopped. Dominated by dust emission, the Large Magellanic Cloud’s infrared appearance is different from views in optical images. But this galaxy’s well-known Tarantula Nebula still stands out, easily seen here as the brightest region to the left of center. A mere 160,000 light-years distant, the Large Cloud of Magellan is about 30,000 light-years across.

Posted by Stephen Hawking/Prof.Rajeev Tripathi