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APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 4:10 am
by APOD Robot
Image NGC 1333: Stellar Nursery in Perseus

Explanation: NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud. This striking close-up spans about two full moons on the sky or just over 15 light-years at the estimated distance of NGC 1333. It shows details of the dusty region along with telltale hints of contrasty red emission from Herbig-Haro objects, jets and shocked glowing gas emanating from recently formed stars. In fact, NGC 1333 contains hundreds of stars less than a million years old, most still hidden from optical telescopes by the pervasive stardust. The chaotic environment may be similar to one in which our own Sun formed over 4.5 billion years ago.

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Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 9:30 am
by Agent Buchwald
Christ, it looks like the howling face of some demon dog! :ohno:

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 9:46 am
by starsurfer
Agent Buchwald wrote: Wed Mar 27, 2019 9:30 am Christ, it looks like the howling face of some demon dog! :ohno:
It looks like a reflection nebula with Herbig Haro objects? :?:

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 11:35 am
by orin stepanek
Oh I can see the dog shape! It is a beautiful picture though! 8-) Makes a beautiful PC wallpaper! :D It'll be a background for tomorrow! :? I love all the color in it!

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 12:47 pm
by HellCat
Really? "Contrasty" ?

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 1:33 pm
by Chris Peterson
HellCat wrote: Wed Mar 27, 2019 12:47 pm Really? "Contrasty" ?
Seems pretty descriptive to me. You have another adjective you prefer?

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 4:09 pm
by MarkBour
As I read the caption today, I wondered what the two prominent stars were in the image, particularly the one at the center of the reflection region. I thought perhaps that was Algol. Dear fellow starship asterisk travellers, I'm wondering how you would go about answering such a question, and what tools you would use?

I tried playing around with SIMBAD. As I've noted, it's an amazing resource, but I surely could use some instruction in its proper use (and maybe an entire astronomy course to understand what it lists). I'm now guessing that the two stars in the image are not bright enough in Earth's skies to be famous and named. The best I can tell, the object at the center of the blue reflection nebula here is "BD +30 549" and rather than just calling it a star, they call it a "young stellar object". Algol is evidently quite far away from the field of view for today's APOD and is much brighter (viewed from Earth) than these objects.

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 11:23 pm
by Ann
MarkBour wrote: Wed Mar 27, 2019 4:09 pm As I read the caption today, I wondered what the two prominent stars were in the image, particularly the one at the center of the reflection region. I thought perhaps that was Algol. Dear fellow starship asterisk travellers, I'm wondering how you would go about answering such a question, and what tools you would use?

I tried playing around with SIMBAD. As I've noted, it's an amazing resource, but I surely could use some instruction in its proper use (and maybe an entire astronomy course to understand what it lists). I'm now guessing that the two stars in the image are not bright enough in Earth's skies to be famous and named. The best I can tell, the object at the center of the blue reflection nebula here is "BD +30 549" and rather than just calling it a star, they call it a "young stellar object". Algol is evidently quite far away from the field of view for today's APOD and is much brighter (viewed from Earth) than these objects.
I would, as always, use my software Guide.

Then I would click "n" for "NGC object" and fill in "1333". This would take me to NGC 1333. My software shows me a small nebula, and as I zoom in, I can see a tiny star inside the brightest part of the nebula. It is a faint 10th magnitude star, very faint. The graphics of the nebula provided by my software shows more stars in there, but only this one star is "clickable". I click it to find out more about the star.

I always check for an HD designation for every star I look up, but in this case there is none. The star does have a Hipparcos and a Tycho designation, HIP 16243 or TYC 2343 624. I use the Hipparcos designation to check the star in Simbad. According to Simbad, the star is indeed BD+30 549. Simbad described it as a "Young Stellar Object", which is certainly true. There is an accompanying DSS picture of the star, which shows it sitting in a blue reflection nebula. Check. The probable spectral class of BD+30 549 is given by Simbad as B8:p C ~. All I get out of that is that the star probably is of late spectral type B.

Simbad tells us several things about this star, like its coordinates. I always use the ICRS coordinates, because they are the ones I can use in my software to get to an object by filling in the right ascension and declination coordinates. The coordinates given for this star shows that it is in the northern hemisphere (because of the + sign in the declination). More specifically, the star is in Perseus, although close to the borders of Taurus and Aries. (And I figured that out by checking my software, not by computing the star's position from the coordinates in Simbad.)

The proper motion of a star indicates the intrinsic motion of the star, how it moves across the sky from our point of view. Check out this 2 MB picture to see the proper motion of the famous double star 61 Cygni.

The radial velocity of a star is how it moves along our line of sight. (Or more specifically, I think it indicates if the star appears to move towards us or away from us, in relation to our own motion in our orbit around the Galaxy.)

The parallax of a star is how it appears to move "back and forth" as the Earth moves from one point in its orbit around the Sun to an "opposite point" six months later. Proxima Centauri, the most nearby star after the Sun, shows the largest parallax of all stars in the sky. Its parallax is 771.64 ± 2.60 milliarcseconds. This parallax is so large that we can say with confidence that Proxima Centauri is located 4.227 ± 0.014 light-years from us.

But BD+30 549? Its parallax is only 3.3836 [± 0.0831] milliarcseconds. I guess that is a Hubble or possibly Gaia parallax, because there is no way that Hipparcos could measure it so precisely. I leave it to you to figure out how far away that makes BD+30 549!

The "fluxes" shows how bright the star is in different wavelengths, from ultraviolet to infrared. The "magnitude" of a star, unless otherwise stated, usually refers to the star's V magnitude, its magnitude in yellow-green light.

So much for Simbad and BD+30 549. Finally I decided I would check out Algol, again by using my software Guide, by writing "Algol" in the "Object name" box. Algol is a second magnitude star, more than eight magnitudes brighter in the sky than BD+30 549. But lo and behold, Algol and BD+30 549 belong to (sort of) the same spectral class, at least: Both are B8-type stars.

But of course, Algol and BD+30 549 are very, very different stars, for all of that. Algol is the famous "Algol variable", where a main sequence star has stolen huge amounts of mass from its swollen companion. As a result, the secondary star has become the primary, a "blue straggler" in all its glory, while the red giant has shrunk to a pitiful remainder of its former ruby splendour.

Ann

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Wed Mar 27, 2019 11:59 pm
by Nitpicker
Mark,

Stellarium is free software, and can be used in much the same way as Ann described her use of Guide.

This is what it looks like:
ngc1333.PNG
ngc1333a.PNG

Sibling green envy rivalry in Stellar Nursery

Posted: Thu Mar 28, 2019 5:17 pm
by neufer
http://www.spitzer.caltech.edu/images/1521-ssc2005-24a-Chaotic-Star-Birth wrote:


<<NGC 1333 epitomizes the beautiful chaos of a dense group of stars being born. Most of the visible light from the young stars in this region is obscured by the dense, dusty cloud in which they formed. With NASA's Spitzer Space Telescope, scientists can detect the infrared light from these objects. This allows a look through the dust to gain a more detailed understanding of how stars like our sun begin their lives. The young stars in NGC 1333 do not form a single cluster, but are split between two sub-groups. One group is to the north near the nebula shown as red in the image. The other group is south, where the features shown in yellow and green abound in the densest part of the natal gas cloud. With the sharp infrared eyes of Spitzer, scientists can detect and characterize the warm and dusty disks of material that surround forming stars.

The knotty yellow-green features located in the lower portion of the image are glowing shock fronts where jets of material, spewed from extremely young embryonic stars, are plowing into the cold, dense gas nearby. The sheer number of separate jets that appear in this region is unprecedented. This leads scientists to believe that by stirring up the cold gas, the jets may contribute to the eventual dispersal of the gas cloud, preventing more stars from forming in NGC 1333.

In contrast, the upper portion of the image is dominated by the infrared light from warm dust, shown as red.>>
https://en.wikipedia.org/wiki/NGC_1333 wrote: :arrow: <<In this image the NASA/ESA Hubble Space Telescope has captured the smoking gun of a newborn star, the Herbig–Haro objects numbered 7 to 11 (HH 7–11). These five objects, visible in blue in the top centre of the image, lie within NGC 1333, a reflection nebula full of gas and dust found about a thousand light-years away from Earth. Herbig-Haro objects like HH 7–11 are transient phenomena. Travelling away from the star that created them, at a speed of up to 70 kilometres per second they disappear into nothingness within a few tens of thousands of years. The young star that is the source of HH 7–11 is called SVS 13 and all five objects are moving away from SVS 13 toward the upper left. The current distance between HH 7 and SVS 13 is about 20,000 times the distance between Earth and the Sun. Herbig–Haro objects are formed when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds. The Herbig–Haro objects visible in this image are no exception to this and were formed when the jets from the newborn star SVS 13 collided with the surrounding clouds. These collisions created the five brilliant clumps of light within the reflection nebula.>>

https://apod.nasa.gov/apod/ap051124.html
https://apod.nasa.gov/apod/ap070521.html

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Tue Apr 02, 2019 2:15 pm
by neufer

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Mon Apr 08, 2019 5:53 pm
by HellCat
Chris Peterson wrote: Wed Mar 27, 2019 1:33 pm
HellCat wrote: Wed Mar 27, 2019 12:47 pm Really? "Contrasty" ?
Seems pretty descriptive to me. You have another adjective you prefer?
High contrast would be better. I try to respect the fact that all the other languages APoD gets translated into may not have the same range as modern English. Keeping things simpler is not only better writing, but better for communications in general.

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Mon Apr 08, 2019 8:13 pm
by geckzilla
HellCat wrote: Mon Apr 08, 2019 5:53 pm . . . may not have the same range as modern English . . .
I have a pretty hard time believing this

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Mon Apr 08, 2019 9:30 pm
by Chris Peterson
geckzilla wrote: Mon Apr 08, 2019 8:13 pm
HellCat wrote: Mon Apr 08, 2019 5:53 pm . . . may not have the same range as modern English . . .
I have a pretty hard time believing this
Well, English has, by far, the largest vocabulary of any language, and a more flexible and rich range of syntactical possibilities than most. But that doesn't mean it can't be effectively translated into other languages. "Contrasty" (which is a perfectly good English word, and carries a subtly different sense than "high contrast", especially with images) might not have a direct translation to a single word in some languages. But the concept can certainly be accurately expressed in any language by the use of several words.

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Mon Apr 08, 2019 9:57 pm
by geckzilla
Chris Peterson wrote: Mon Apr 08, 2019 9:30 pmBut the concept can certainly be accurately expressed in any language by the use of several words.
the whole thing could probably be more succinctly described as a kind of astronomical chiaroscuro, and we can thank the Italians for that one

Re: APOD: NGC 1333: Stellar Nursery in Perseus (2019 Mar 27)

Posted: Mon Apr 22, 2019 5:11 am
by MarkBour
Nitpicker wrote: Wed Mar 27, 2019 11:59 pm Mark,

Stellarium is free software, and can be used in much the same way as Ann described her use of Guide.

This is what it looks like:
ngc1333.PNG
ngc1333a.PNG
Thanks! I've played around with Stellarium a very little. I will definitely explore it some more. Or explore with it some more, that is.