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ApJ. The Most Distant Stars in the Milky Way
Posted: Sat Jul 12, 2014 7:12 pm
by MargaritaMc
http://iopscience.iop.org/2041-8205/790/1/L5/
The Astrophysical Journal Letters Volume 790 Number 1
John J. Bochanski et al. 2014 ApJ 790 L5 doi:10.1088/2041-8205/790/1/L5
THE MOST DISTANT STARS IN THE MILKY WAY
Abstract:
We report on the discovery of the most distant Milky Way (MW) stars known to date: ULAS J001535.72+015549.6 and ULAS J074417.48+253233.0. These stars were selected as M giant candidates based on their infrared and optical colors and lack of proper motions. We spectroscopically confirmed them as outer halo giants using the MMT/Red Channel spectrograph. Both stars have large estimated distances, with ULAS J001535.72+015549.6 at 274 ± 74 kpc and ULAS J074417.48+253233.0 at 238 ± 64 kpc, making them the first MW stars discovered beyond 200 kpc. ULAS J001535.72+015549.6 and ULAS J074417.48+253233.0 are both moving away from the Galactic center at 52 ± 10 km s–1 and 24 ± 10 km s–1, respectively. Using their distances and kinematics, we considered possible origins such as: tidal stripping from a dwarf galaxy, ejection from the MW's disk, or membership in an undetected dwarf galaxy. These M giants, along with two inner halo giants that were also confirmed during this campaign, are the first to map largely unexplored regions of our Galaxy's outer halo.
http://www.haverford.edu/physics-astro/ ... press.html
The ApJ article is behind a mild (£5.00/$9.00) paywall.
But the lead author has written about this research in Sky and Telescope
http://www.skyandtelescope.com/astronom ... 070920142/
AJ: Hunting the Most Distant Stars in the Milky Way
Posted: Sat Jul 12, 2014 8:42 pm
by bystander
Here is a companion piece:
Hunting the Most Distant Stars in the Milky Way: Methods and Initial Results -John J. Bochanski
et al
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Sun Jul 13, 2014 1:42 pm
by BDanielMayfield
The journalist reporting this news could be accused of just a bit of bias, (since it was his very own research being reported) but it is an important finding and someone had to get the news out.
I've been reading John Bochanski's articles with pleasure on Sky and Telescopes' site since he started out as an intern reporter. Congratulations John
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Sun Jul 13, 2014 5:51 pm
by MargaritaMc
Yes, and he does "own up" in the opening paragraph!
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Sun Jul 13, 2014 6:07 pm
by Beyond
Sometimes... when one gets lost in a crowd... one has to toot one's own horn to keep track of where one is and let others know that you're in the vicinity. :toot: :toot:
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Mon Jul 14, 2014 12:12 am
by rstevenson
Wow! Those are some distant stars. The entire Milky Way galaxy is only about 30 kpc in diameter, and it's only about 8 kpc from here to the center of the MW. So these stars, being over 200 kpc away, are indeed in the outer halo.
Rob (feeling smaller and smaller...)
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Thu Jul 17, 2014 7:26 pm
by MargaritaMc
rstevenson wrote:Wow! Those are some distant stars. The entire Milky Way galaxy is only about 30 kpc in diameter, and it's only about 8 kpc from here to the center of the MW. So these stars, being over 200 kpc away, are indeed in the outer halo.
Rob (feeling smaller and smaller...)
I had to read the following several times to take in what was being said:
http://www.haverford.edu/physics-astro/ ... press.html
This simulated image demonstrates how small the Milky Way would look from the location of ULAS J0744+25, nearly 775,000 light years away. This star, along with ULAS J0015+01, are the most distant stars ever associated with our Galaxy, and are
about five times further away than the Large Magellanic Cloud, one of the Milky Way's closest galactic neighbors
That certainly is the lone star state...
Margarita (feeling even smaller...)
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Thu Jul 17, 2014 9:07 pm
by BMAONE23
The night sky of any planet orbiting this star would most certainly consist of just galaxies and be mostly black to the unaided eye
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Thu Jul 17, 2014 9:50 pm
by geckzilla
Must be excellent for studying the universe. No galaxy in your face obscuring a large portion of the sky.
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Fri Jul 18, 2014 3:10 pm
by rstevenson
Beings on any planet orbiting such a star would know, without the slightest doubt, that they're never going to visit another star system. We here, surrounded by billions of relatively close stars, can at least still dream of doing just that some day. It won't be easy, and it won't happen soon, but we're stubborn and clever monkeys, so I think we'll accomplish the task some day.
On the other hand, instead of what I imagine would be a state of terrible loneliness, perhaps they're absolutely convinced that they are special, unique, favoured by fate or Dog (they're all dyslexic), to not be in the hurly-burly of such a crowded thing as a galaxy.
Rob
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Tue Jul 22, 2014 5:07 pm
by bystander
MargaritaMc wrote:
...
The ApJ article is behind a mild (£5.00/$9.00) paywall
...
arXiv:1407.2610
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Tue Jul 29, 2014 11:55 am
by MargaritaMc
bystander wrote:MargaritaMc wrote:
...
The ApJ article is behind a mild (£5.00/$9.00) paywall
...
arXiv:1407.2610
Now why didn't I find that on Google scholar?! It must be your magic touch, bystander.
Many thanks.
M
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Tue Jul 29, 2014 6:32 pm
by bystander
MargaritaMc wrote:Now why didn't I find that on Google scholar?
I use
Google's Advanced Search Tool. I place a significant part of the paper's title into the
"this exact word or phrase" field and use
"adsabs.harvard.edu" and/or
"arxiv.org/abs" in the
"site or domain" field. I also use the tool to search the Asterisk*, using
"asterisk.apod.com" as the
"site or domain".
edit: There is also the SAO/NASA ADS query page and the arXiv.org search page
Re: ApJ. The Most Distant Stars in the Milky Way
Posted: Wed Jul 30, 2014 8:36 pm
by MargaritaMc
Thank you, bystander. I've made a note of that info and put it where I can refer to it quickly.
M
