SoylentNews

First Runaway Yellow Supergiant Star Discovered

posted by janrinok on Thursday March 29 2018, @07:44PM   
from the look-out-Hollywood-Blvd dept.

takyon writes:

Astronomers spy runaway star in Small Magellanic Cloud

Astronomers at Lowell Observatory in Flagstaff, Arizona, said on March 27, 2018. that they've discovered a rare runaway star in the Small Magellanic Cloud, a small satellite galaxy of our Milky Way. The star is speeding across its little galaxy at 300,000 miles per hour (500,000 km/hour). At that speed, it would take about half a minute to travel from Los Angeles to New York. The runaway star is designated J01020100-7122208, and it's believed to have once been one of two stars orbiting around each other. Astronomers think that, when the companion star exploded as a supernova, the tremendous release of energy flung J01020100-7122208 into space at its high speed.

The star is the first runaway yellow supergiant star ever discovered, and only the second evolved runaway star to be found in another galaxy. A paper about its discovery has been accepted for publication in the peer-reviewed Astronomical Journal and is currently published online via Arxiv. A statement from Lowell Observatory said:

After ten million years of traveling through space, the star evolved into a yellow supergiant, the object that we see today. Its journey took it 1.6 degrees across the sky, about three times the diameter of the full moon. The star will continue speeding through space until it too blows up as a supernova, likely in another three million years or so. When that happens, heavier elements will be created, and the resulting supernova remnant may form new stars or even planets on the outer edge of the Small Magellanic Cloud.

These stars typically only spend thousands or tens of thousands of years in the yellow supergiant phase before becoming red supergiants.

---

Original Submission

• Re:The article (Score: 3, Informative) by martyb on Friday March 30 2018, @01:01AM

  by martyb (76) on Friday March 30 2018, @01:01AM (#660253) Journal

  corey wrote [soylentnews.org]:

  The article is so dumbed down, especially the LA to NYC analogy.

  That speed is not much in space, and everything is relative too. Our solar system (and sun) are moving at estimated 250 km/s (quick, tell me how long it'd take if I was going that fast from one American city to another so I can understand) as the galaxy spins. Now I guess the LMC is non spiral but still.

  Maybe the star is moving at a different velocity angle than other stars in the area. That'd be useful to know.

  Yes, the article does appear to be "dumbed down" to be much more accessible to the average reader. Conveniently, they also provided a link to a copy of the actual journal article on Arxiv [arxiv.org]:

  Neugent et al. (2010) conducted a radial velocity study of yellow stars seen in the direction of the Small Magellanic Cloud (SMC) in order to identify its yellow supergiant (YSG) population. As shown in Figure 1, the observed radial velocities are either clustered around 0 km s⁻¹ (as expected for foreground yellow dwarfs), or around the SMC’s heliocentric radial velocity of 158 km s⁻¹ (Richter et al. 1987) as indicated by the black line and expected for SMC yellow supergiants. One star, J01020100-7122208, however, has a heliocentric radial velocity of around 300 km s⁻¹, 140 km s⁻¹ greater than expected. Neugent et al. (2010) don’t explicitly comment on this star; at the time we believed it to be a likely short-period binary. However, we have now completed additional observations that rule out this explanation. Instead, this star is the first runaway YSG discovered and the second evolved runaway star discovered in another galaxy.

  In short, it is moving at 140 km/s above and beyond its expected radial velocity.

  --
  Wit is intellect, dancing.

  Parent

  Starting Score:	1		point
  Moderation		+1
  Informative=1, Total=1
  Extra 'Informative' Modifier		0
  Karma-Bonus Modifier		+1
  Total Score:		3