Astronomers In finding the Fringe of Our Galaxy

The Andromeda Galaxy captured by the NASA Galaxy Evolution Mapper in 2012.

The Andromeda Galaxy captured by way of the NASA Galaxy Evolution Mapper in 2012.
Symbol: NASA/JPL-Caltech

Within the quest to search out the outer limits of our galaxy, astronomers have came upon over 200 stars that shape the Milky Manner’s edge, probably the most far away of which is over 1,000,000 light-years away—just about midway to the Andromeda galaxy.

The 208 stars the researchers recognized are referred to as RR Lyrae stars, which might be stars with a brightness that may trade as seen from Earth. Those stars are normally outdated and brighten and dim at common periods, which is a mechanism that permits scientists to calculate how some distance away they’re. Via calculating the gap to those RR Lyrae stars, the staff discovered that the farthest of the bunch was once positioned about midway between the Milky Manner and the Andromeda galaxy, considered one of our cosmic next-door neighbors.

“This find out about is redefining what constitutes the outer limits of our galaxy,” stated Raja GuhaThakurta in a press unlock. GuhaThakurta is professor and chair of astronomy and astrophysics on the College of California Santa Cruz. “Our galaxy and Andromeda are each so large, there’s hardly ever any house between the 2 galaxies.”

Image for article titled Astronomers Find the Edge of Our Galaxy

Representation: NASA, ESA, AND A. FEILD (STSCI)

The Milky Manner galaxy is composed of a couple of other portions, the main of which is a skinny, spiral disk about 100,000 light-years throughout. Our house sun device sits on probably the most hands of this disk. An interior and outer halo encompass the disk, and those halos include one of the most oldest stars in our galaxy.

Previous studies have placed the edge of the outer halo at 1 million light-years from the Milky Way’s center, but based on the new work, the edge of this halo should be about 1.04 million light-years from the galactic center. Yuting Feng, a doctoral student at the university working with GuhaThakurta, led the study and is presenting the findings this week on the American Astronomical Society assembly in Seattle.

“We had been in a position to make use of those variable stars as dependable tracers to pin down the distances,” stated Yuting Feng, a doctoral scholar on the college operating with GuhaThakurta. “Our observations ascertain the theoretical estimates of the dimensions of the halo, in order that’s a very powerful end result.”

House is huge and lonely—however we will be able to really feel just a little cozier realizing that our galactic neighbor is nearer than we concept.

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