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Milky Way’s Most Distant Stars Spotted

This simulated image demonstrates how small the Milky Way would look from the location of ULAS J0744+25, nearly 775,000 light years away, about five times further away than the Large Magellanic Cloud.  Credits: Visualization Software:  Uniview by SCISS Data: SOHO (ESA & NASA), John Bochanski (Haverford College) and Jackie Faherty (American Museum of Natural History and Carnegie Institute's Department of Terrestrial Magnetism)
A simulated image demonstrates how small the Milky Way would look from the star ULAS J0744+25. Image courtesy Visualization Software: Uniview by SCISS Data: SOHO (ESA & NASA), John Bochanski (Haverford College), and Jackie Faherty (American Museum of Natural History and Carnegie Institute’s Department of Terrestrial Magnetism)

Like a boat floating in a vast, empty ocean, a newly discovered star now holds the record as the most distant one in our Milky Way galaxy.

Galaxies are islands of stars spread throughout space, essentially, separated by voids littered with relatively few stars. The newly spotted Milky Way star, dubbed ULAS J0015+01, is a distant red giant that resides a jaw-dropping 900,000 light-years away. The most remarkable thing about the star is that it is still within the gravitational grasp of our own galaxy.

It was spotted along with another cool stellar old-timer named ULAS J0744+25, which is some 775,000  light-years away, by a team led by John Bochanski of Haverford College in Haverford, Pennsylvania.

The two stars are more than 50 percent farther from the sun than any known star in the Milky Way, or about five times more distant than the Large Magellanic Cloud, a dwarf galaxy that circles our galaxy. In fact, the two stars lie about one third of the distance to the Andromeda galaxy, the Milky Way’s sister spiral in the Local Group of nearby galaxies.

“The distances to these two stars are almost too large to comprehend,” says Bochanski. “To put it in perspective, when the light from ULAS J0015+01 left the star, our early human ancestors were just starting to make fires here on Earth.”

The feeble light from both red giants were picked up by the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey.

It’s a pretty lonely place beyond the Milky Way’s halo. Only seven stars having been cataloged to date that lie beyond the 400,000 light-year halo of stars that cocoon our galaxy.

But beyond the extreme records, these distant stars interest astronomers because they call the Milky Way’s extended halo their home. As far-flung outliers from the galaxy, they may shed light on its origin and evolution. Current theories point to our galaxy colliding with many smaller dwarf galaxies in the distant past, resulting in small smatterings of stars thrown out into intergalactic space. Both ULAS J0744+25 and ULAS J0015+01 may in fact be all that is left over of one such ancient collision.

See for Yourself

Okay, so while these stars are only visible with world-class telescopes, what about the most distant star visible to the naked eye?

If we are talking in terms of the brightest, most distant star then that would be Deneb, the lead star in the summertime constellation Cygnus. Despite having an estimated average distance of 1,400 light-years away, Deneb shines as one of the brightest stars in the heavens.

This sky-chart shows the location of Deneb, the lead star in the constellation Cygnus. Credit: SkySafari
This sky chart shows the location of Deneb, the lead star in the constellation Cygnus. Credit: SkySafari

It is easy to find at this time of the year for those in the Northern Hemisphere, since it lies overhead during late nights and pins down one of the corners of the Summer Triangle stellar pattern.

But the record as the farthest star we can see with the naked eye would probably have to go to Rho Cassiopeiae—at an astounding 8,000 light-years from Earth. That is 472,000 trillion miles (760,000 trillion kilometers) away.

This skychart shows the constellation Cassiopeia in the northeast evening sky, home to Rho Cass - the most distant star the unaided human eye can see.  Credit: SkySfari
This sky chart shows the constellation Cassiopeia in the northeast evening sky, home to Rho Cass, the most distant star the unaided human eye can see. Credit: SkySfari

Shining at magnitude +4.5,  it is just visible as a very faint star from the countryside or darker suburbs. The star glints from within the W- or M-shaped (depending on season) constellation Cassiopeia, the Queen. It can be seen throughout the year from mid-northern latitude locations, always in the general vicinity of the North Star.

The reason we can actually see Rho Cass is because it is classified as a hypergiant star, one that has a diameter some 500 times wider than our own sun, which it outshines 10,000 times more brightly. Astronomers believe this makes for an explosive combination and so computer models are suggesting that this stellar monster may explode as a supernovae anytime.

So, try and catch it while you can.

Follow Andrew Fazekas, the Night Sky Guy, on Twitter and Facebook.

 

Comments

  1. david
    malaysia
    August 17, 12:43 am

    is there any possibilites that galaxy will crash????

  2. david
    jamica
    August 17, 12:41 am

    is this galaxy will crash each other?because each of them as their own gravity force….so is there any possiblites that galaxys will crash???

  3. sammy
    namibia
    July 19, 9:43 am

    wow amazing

  4. Carl Gayfield
    46545
    July 18, 4:16 pm

    I thought Venus was our closest neigbor, Then Mercury followed by Mars.

  5. Bob Az
    Phoenix
    July 18, 3:12 pm

    TO THE MODERATOR: I clicked “submit” accidentally. Please finish my comment with “… the Local Group, our galaxy cluster that includes the MW and Andromeda.”

  6. Bob Az
    Phoenix AZ
    July 18, 3:10 pm

    @Chris: Yes, more distant individual stars are visible in galaxies millions of light years away, but these stars are special because they’re in the outermost domain of the Milky Way. They’re unlikely to have been formed there (they’re not in the relatively dense disk nor the original MW halo) so an explanation is needed. Thus the hypothesis of being detritus from an earlier collision between the MW and one of the many irregular dwarf galaxies that are part of the Local Group, our galaxy cluster that includes the MW and Andromeda.

  7. kevan hubbard
    United Kingdom
    July 18, 9:52 am

    But are they in our galaxy or rouge cast out stars?bit like the question is tristain de China Africa or Sth america?

  8. varadharaj
    July 17, 11:18 pm

    can we see it from south india

  9. Bo Ray
    Biloxi, MS
    July 17, 5:47 pm

    The article says “computer models are suggesting that this stellar monster may explode as a supernovae anytime”. It’s mind boggling to think that if and when we see it explode it actually happened 8000 years in the past. For all we know it exploded when the Egyptians were building the pyramids and we won’t know anything about it for another 5000 years!

  10. louis
    malta
    July 17, 5:39 pm

    I wonder could ever humans get out of the galaxy,ok thats impossible,but 1 second no worry the galaxy is us after all,nothing is far away really…………

  11. Patrick
    Santiago, Chile
    July 17, 4:06 pm

    What a shame!. We live in the southern hemisphere. Isn´t there any information of this kind for us?.
    Thanks.

  12. Terry
    atlanta
    July 14, 9:38 am

    According to Perry Como, you can catch a falling star and put it in your pocket!

  13. AM
    Pa
    July 12, 9:12 pm

    Thank you for the knowledge. I never saw the stars in this way. Exciting! Also, you took care of a question I have been waiting to be answered.

  14. Chris
    July 11, 2:41 pm

    Aren’t there quite a few galaxies that can be seen with the naked eye? I understand that we can’t distinguish the light from any one star from any other (outside the Milky Way, with the naked eye), but the light we see from a galaxy is actually light from stars — stars that are more distant than Rho Cassiopeiae. Just a thought…