APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

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APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

Post by APOD Robot » Sat Mar 26, 2011 4:14 am

Image T Tauri and Hind's Variable Nebula

Explanation: The yellowish star near center in this remarkable telescopic skyview is T Tauri, prototype of the class of T Tauri variable stars. Nearby it is a dusty yellow cosmic cloud historically known as Hind's Variable Nebula (NGC 1555). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing region. T Tauri stars are now generally recognized as young (less than a few million years old), sun-like stars still in the early stages of formation. To further complicate the picture, infrared observations indicate that T Tauri itself is part of a multiple system and suggest that the associated Hind's Nebula may also contain a very young stellar object. The naturally colored image spans about 4 light-years at the estimated distance of T Tauri.

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orin stepanek
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Re: APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

Post by orin stepanek » Sat Mar 26, 2011 11:39 am

Awesome! :D Looks like the star is still hatching; as it is burning out the dust around itself! :!:
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T Tauri Tutorial

Post by neufer » Sat Mar 26, 2011 12:28 pm

Image
http://www.solstation.com/stars/sol.htm wrote:
<<After its birth some 4.6 billion years ago, the Sun had an extremely active magnetic field during its infancy, with gigantic dark star- or Sun-spots that sometimes covered its polar regions. Indeed, sometime after the tenuous gas of the Solar nebula began collapsing into the proto-Sun within its host molecular cloud, a strong magnetic field developed that was instrumental in transporting rotational energy away from its core region in bi-polar jets of gas so that centrifugal forces created by the nebula's collapse did not grow so much as to halt continuing gravitational contraction. Before Sol finished forming, around a tenth of the gas and dust around it may have been ejected by infalling through its accretion disk and then being blown out by bi-polar jets to produce two giant lobes of molecular gas, and bow shocks from the jets hitting the surrounding stellar nebula. Known as Herbig-Haro objects since their discovery in the early 1950s, these lobes typically extend a few light-years in length, have masses similar or larger than the developing star itself, and are moving apart at speeds of tens to a few hundred kilometers per second. Stretching for several light-years, such bi-polar jets may be driven at supersonic speeds by an intense magnetic field at the axis of rotation of an embryonic star less than a few hundred million years old.

The gas and dust moving outward carried angular momentum away from the developing Sun and allowed accretion to continue, but also churned up the surrounding nebula and so provided the necessary turbulence to slow down its collapse. Eventually, the supply of infalling matter ran out and shut down Sol's bi-polar jets. Subsequently, much of the surrounding gas and dust that remained around Sol was blown away, by the young star's radiation in T-Tauri winds after core nuclear fusion was turned on. >>
http://asterisk.apod.com/viewtopic.php? ... 87#p108787
http://asterisk.apod.com/viewtopic.php? ... 03#p120303
http://asterisk.apod.com/viewtopic.php? ... 81#p137381
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Re: APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

Post by mexhunter » Sat Mar 26, 2011 12:47 pm

This is a picture to be seen and admired it. Undoubtedly it is a very beautiful image.
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Re: APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

Post by NoelC » Sat Mar 26, 2011 2:04 pm

Nice, beautiful image! Really feels like you're out there watching.

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Re: APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

Post by jnorris886 » Sun Mar 27, 2011 8:03 pm

The difference between brightness variations between the star and the nebula is due to the significant distance between them. Assuming that the star is the light source for itself and the nebula, the time difference between the variations can be easily calculated by dividing the distance between them by the speed of light.

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Re: APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

Post by neufer » Sun Mar 27, 2011 8:11 pm

jnorris886 wrote:
The difference between brightness variations between the star and the nebula is due to the significant distance between them. Assuming that the star is the light source for itself and the nebula, the time difference between the variations can be easily calculated by dividing the distance between them by the speed of light.
That is a ballpark approximation which assumes that they are both the same distance from Earth.

Hind's Variable Nebula might be closer or further from Earth.
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Re: APOD: T Tauri and Hind's Variable Nebula (2011 Mar 26)

Post by NoelC » Mon Mar 28, 2011 1:35 am

That might be so, but do the brightness variations actually mirror one another?

-Noel