Science 6.03.2020

1066 6 MARCH 2020 • VOL 367 ISSUE 6482 sciencemag.org SCIENCE

PHOTO: ATATÜRK UNIVERSITY ASTROPHYSICS RESEARCH AND APPLICATION CENTER/ANADOLU IMAGES

NEWS | IN DEPTH

I

nternational megaprojects that cost well

over $1 billion generate most of the ex-

citement in observational astronomy

today: the 39-meter Extremely Large

Telescope under construction in Chile,

for example, or the Thirty Meter Tele-

scope, controversial because of its proposed

location on Mauna Kea, a mountain sacred

to some Native Hawaiians.

But smaller telescopes still do cutting-

edge science as well. And Turkish scientists

are eagerly awaiting the completion of the

new Eastern Anatolia Observatory (DAG), a

4-meter optical and infrared telescope ex-

pected to come online next year. Its main

structure is scheduled to be shipped

to the site, a 3170-meter mountaintop

in northeastern Turkey, this month;

polishing and grinding of the primary

mirror is nearly done.

Despite its modest $34 million

price tag, DAG will be one of Asia’s

largest optical telescopes and Tur-

key’s largest science project. Its de-

velopers hope DAG will make Turkey

a regional astronomy hub and help

nurture its astronomy community.

“We are dreaming of using the instru-

ments on DAG,” says Ozgur Basturk,

an exoplanet scientist at Ankara Uni-

versity. “With a 4-meter telescope, we

can do much better and be more com-

petitive in our field.”

Turkey’s largest telescope today is a

1.5-meter reflector near the city of An-

talya on the Mediterranean coast. The new

facility will sit well above haze and humidity

and far from urban light pollution, and enjoy

288 clear nights per year on average. Its de-

sign and construction, financed by the Turk-

ish government, has involved scientists at

40 universities in the region, along with Eu-

ropean academic and industrial partners.

“It’s not a 40-meter telescope of course,”

says Laurent Jolissaint of the University of

Applied Sciences and Arts of Western Swit-

zerland, the project’s lead optical engineer,

“but we put everything into it. The optics

system is the same essentially as the very

newest systems.” DAG will be run by the

Astrophysics Research and Application Cen-

ter at Atatürk University in Erzurum, a city in

eastern Turkey.

Turkish scientists have little access to the

world’s largest telescopes. The European

Southern Observatory (ESO) in Chile, for in-

stance, prioritizes observing time for projects

led by scientists from the 16 nations that have

helped pay for the facility and contribute to

its €162 million annual budget. “In principle

anyone can apply to use these telescopes, but

the competition is very high, so the research

quality [of your proposals] should be high,”

says astronomer Sinan Alis of Istanbul Uni-

versity. “You have to somehow reach that

level to be able to compete.” In 2010, Turk-

ish astronomers began to lobby their govern-

ment to apply for ESO membership, but they

gave up a few years ago, their hopes dashed

by Turkey’s economic crisis. (Another devel-

oping country, Brazil, dropped its member-

ship bid last year because it could not afford

€270 million in fees over the next decade.)

Unable to make observations themselves,

many Turkish astronomers fall back on archi-

val data from large telescopes that have al-

ready been picked over by other astronomers,

who can take years to release them. Some

Turkish astronomers have struck up collabo-

rations with teams from ESO member coun-

tries, but even then, getting travel funded is

often difficult.

That’s why the new telescope will be such

a boon, Basturk says—for instance, for his

exoplanet research. DAG will allow him

to use one of the standard strategies for

hunting exoplanets: monitoring stars for

a wobbling motion that results from the

gravitational tug of an orbiting planet. But

like other premier telescopes, DAG will also

have a coronagraph, an instrument that

masks bright stars to remove their glare so

that dim planets orbiting them can be im-

aged directly. New technology will enable

the coronagraph to block multiple stars at

the same time, needed to hunt for exoplan-

ets in star systems that, unlike our own,

have two stars or more.

DAG’s large aperture will enable it to

capture light from distant, faint objects like

high redshift galaxies, allowing astronomers

to probe far back into the universe’s history.

That’s important for Alis, who hopes to use

DAG to follow up on data from the Spektr-

RG space observatory, a Russian-German sat-

ellite launched last year to map the x-ray sky

(Science, 14 June 2019, p. 1020). Many objects

can produce x-rays, from black holes

at the centers of galaxies to smaller

black holes or neutron stars consum-

ing mass from a companion star. “We

need to follow up with optical and in-

frared to see what they actually are,”

Alis said.

In an ironic twist, DAG officials

say astronomers from several Eu-

ropean countries have shown in-

terest in Turkey’s new observatory,

despite their access to ESO’s mega-

telescopes, drawn by the location—

there are few others in the Northern

Hemisphere at that longitude—and

affordable observation time. “We

envision DAG as an international

observatory,” says the project’s di-

rector, Cahit Yes ̧ilyaprak of Atatürk

University. “We do not have a prefer-

ence about the origin of the proposals, as

long as the best science cases are proposed

and conducted.”

But the biggest impact will be in Tur-

key itself. Designing the telescope has al-

ready pushed science in other fields. For

instance, dozens of optical, mechanical,

and computer engineers helped design the

telescope’s adaptive optics system, which

will sharpen its images, and its derotator,

a device that keeps the telescope trained on

the same spot as the Earth rotates. “These

are big deals for a developing country,”

Yes ̧ilyaprak says. And the telescope itself

will invigorate Turkish astronomy, Alis says.

“Once we have the telescope, the expertise

will pop up.” j

Umar Farooq is a journalist based in Istanbul.

A new telescope, under construction on a 3170-meter mountaintop

in eastern Turkey, is expected to come online next year.

By Umar Farooq

A S T R O N O M Y

New telescope promises boon for Turkish science

The 4-meter Eastern Anatolia Observatory aims to become an affordable regional hub

Published by AAAS