Page 28 - ARUBA TODAY

A28 SCIENCE
Friday 6 april 2018
The center of the Milky Way is teeming with black holes

By SETH BORENSTEIN they emit large amount of
WASHINGTON (AP) — The x-rays as the star's outer lay-
center of our galaxy is er is sucked into the black
teeming with black holes, hole. Those x-rays are what
sort of like a Times Square astronomers observe.
for strange super gravity When astronomers look at
objects, astronomers dis- closer binary black hole sys-
covered. tems they could then see
For decades, scientists the- the ratio between what's
orized that circling in the visible and what's too faint
center of galaxies, includ- to be observed from far
ing ours, were lots of stellar away. Using that ratio,
black holes , collapsed gi- Hailey figures that even
ant stars where the grav- though they only spotted a
ity is so strong even light dozen there must be 300 to
doesn't get out. But they 500 binary black hole sys-
hadn't seen evidence of tems.
them in the Milky Way core But binary black hole sys-
until now. tems are likely only 5 per-
Astronomers poring over This illustration provided by Columbia University shows the supermassive black hole Sagittarius cent of all black holes, so
A, located at the center of the Milky Way Galaxy, surrounded by a cloud of dust and gas within
old x-ray observations have which are 12 smaller black holes, and a closeup of one of the systems. that means there are really
found signs of a dozen Associated Press thousands of them, Hailey
black holes in the inner said.
circle of the Milky Way. people like to study it." trillion kilometers) of the su- Loeb, who wasn't part of There are good reasons
And since most black holes The stellar black holes are permassive black hole at the study, praised the find- the Milky Way's black holes
can't even be spotted that in addition to — and essen- the center. So there's still a ing as exciting but confirm- tend to be in the center of
way, they calculate that tially circling — the already lot of empty space and gas ing what scientists had long the galaxy, Hailey said.
there are likely thousands of known supermassive black amid all those black holes. expected. First, their mass tends to
them there. They estimate hole, called Sagittarius A , But if you took the equiva- The newly confirmed black pull them to the center. But
it could be about 10,000, that's parked at the center lent space around Earth holes are about 10 times mostly the center of the
maybe more, according of the Milky Way. there would be zero black the mass of our sun, as op- galaxy is the perfect "hot
to a study in Wednesday's In the rest of the massive holes, not thousands, Hai- posed to the central super- house" for black hole for-
journal Nature . Milky Way, scientists have ley said. massive black hole, which mation, with lots of dust and
"There's lots of action going only spotted about five Earth is in spiral arm around has the mass of 4 million gas. Hailey said it is "sort of
on there," said study lead dozen black holes so far, 3,000 light years away from suns. Also the ones spot- like a little farm where you
author Chuck Hailey, a Co- Hailey said. the center of the galaxy. (A ted are only the type that have all the right conditions
lumbia University astrophys- The newly discovered light year is 5.9 trillion miles, are binary , where a black to produce and hold on to
icist. "The galactic center is black holes are within or 9.5 trillion kilometers.) hole has partnered with a large number of black
a strange place. That's why about 19.2 trillion miles (30.9 Harvard astronomer Avi another star and together holes."q
SpaceX capsule reaches space

station with food, experiments

By The Associated Press post for this capsule, refur- rocket. SpaceX wants to
A SpaceX capsule carry- bished following a visit two reduce launch costs by
ing food, experiments and years ago. It will remain at- recycling rocket parts. It
other goods for NASA has tached to the space sta- combined a recycled cap-
arrived at the International tion for about a month, re- sule and a recycled rocket
Space Station after a two- turning to Earth in May. once before.q
day journey. The space station is cur-
The Dragon capsule and its rently home to astronauts
6,000-pound shipment was from the U.S., Russia and
captured by the space sta- Japan.

In this image provided by NASA, the Dragon capsule arrives tion's robot arm Wednes- The supply capsule
at the International Space Station on Wednesday, April 4, 2018 day. launched Monday from
with food and experiments. It's the second trip to the Cape Canaveral, Florida,
Associated Press 250-mile-high orbiting out- aboard a used Falcon