Observing Infrastructure at the TÜBİTAK National Observatory (TUG)

The TÜBİTAK National Observatory (TUG) was founded near Antalya in 1997 as Türkiye's first national observatory. Since 2023 it has been part of the Türkiye National Observatories together with the Eastern Anatolia Observatory (DAG). This article summarises the site, its observing conditions and its active telescopes, based on information published by the institution.

Site

The campus lies south-west of Antalya on the Bakırlıtepe summit of the Beydağları range, a branch of the Taurus Mountains, at an altitude of 2,550 metres. The Saklıkent ski resort sits at the foot of the summit. The institution gives the coordinates as roughly 36° 49′ N and 30° 20′ E. About 50 km of road lead from Antalya to Saklıkent, followed by 6 km of mountain road; the institution estimates the whole trip at around an hour and a half.

Climate and sky quality

The temperature on Bakırlıtepe varies by 50–55 °C over the year. According to the institution, the mean temperature is +5 °C, with a low of −28 °C and a high of +22 °C. Mean humidity is around 50 per cent. Winds come mostly from the south-east; the average speed is 17 km/h, but winds of 150 km/h lasting for hours and gusts of up to 270 km/h are listed as the maximum values. Snow stays for about five months, with an average depth of 1.5 metres.

For observing quality, the institution gives a sky background brightness of 21.5 mag/arcsec², seeing of 0.86 arcseconds and about 200 clear nights per year. The averages it quotes for good observatories are 21.4–21.8 mag/arcsec², 0.6–1.0 arcseconds and 200–300 nights a year.

Campus and infrastructure

The institution describes the campus as ten main locations made up of telescope buildings, a security building and operations and service buildings, with a total indoor area of about 3,261 square metres. Water is pumped from the Saklıkent area through a 2,200-metre line, climbing 550 metres to tanks in the main building with a storage capacity of 100 tonnes. The contracted electrical capacity is 300 kVA, backed by two diesel generators and twenty uninterruptible power supplies of various ratings. Internet access runs over a 1 Gbit/s fibre line.

Active telescopes

The institution's history page lists three active telescopes at TUG, offering both photometry and spectroscopy in the visible band. Photometry measures the brightness of a celestial object and how it changes over time. Spectroscopy splits the light into its wavelengths and reveals an object's chemical make-up, temperature and motion.

RTT150

RTT150, a Russian–Turkish partnership, is the largest telescope on the campus with its 1.5-metre primary mirror. This Ritchey–Chrétien telescope weighs about 37 tonnes and sits on an equatorial mount; at its Cassegrain focus the focal ratio is f/7.7 and the focal length about 11.6 metres, and it also has an f/48 Coudé focus. The institution states that the telescope is used for high-resolution astrometric, photometric and spectroscopic work with advanced focal-plane detectors. The Cassegrain focus hosts TFOSC (TUG Faint Object Spectrograph and Camera), Wollaston-prism polarimetry, a multi-object spectroscopy (MOS) option and an EMCCD camera, while the Coudé focus carries spectrograph set-ups and DEFPOS, a dual-etalon Fabry–Perot optical spectrometer. The filter set includes Bessell and SDSS broadband filters as well as narrow-band filters such as Hα, Hβ, [O III] and [S II].

TUG100

TUG100 is a 1-metre Ritchey–Chrétien telescope on an equatorial mount, with a focal ratio of f/10 and a focal length of 10 metres. Its SI 1100 CCD camera uses a back-illuminated 4096 × 4037-pixel sensor cooled to −100 °C, giving 0.31″ per pixel and a field of view of about 21.5′ × 21.5′. The institution states that, thanks to this wide field, the telescope is used for photometry of crowded star fields, exoplanet research and projects on small bodies in the Solar System.

TUG060

TUG060 has a 60-centimetre primary mirror in a Ritchey–Chrétien layout, a focal length of 6 metres and a focal ratio of f/10. Its Andor iKon-L 936 camera provides a 15.6′ × 15.6′ field with a 2048 × 2048-pixel CCD, and a 12-slot filter wheel holds Bessell UBVRI, SDSS and neutral-density filters. According to the institution, photometry projects on long-period variable stars are carried out with this telescope, and atmospheric extinction and standard-system transformation coefficients determined on different dates are shared with users.

A division of labour

The three telescopes complement one another. RTT150, with its large mirror and spectrographs, suits detailed studies of faint objects; TUG100, with its wide field, suits following many stars in the same frame; and TUG060 suits programmes that need long-term monitoring. While the 4-metre telescope of DAG in Erzurum reaches into the infrared, TUG continues its observing services in the visible band.

References

• Antalya TUG Campus · Türkiye National Observatories (trgozlemevleri.gov.tr)
• RTT150 Telescope · Türkiye National Observatories (trgozlemevleri.gov.tr)
• TUG100 Telescope · Türkiye National Observatories (trgozlemevleri.gov.tr)
• TUG060 Telescope · Türkiye National Observatories (trgozlemevleri.gov.tr)
• History · Türkiye National Observatories (trgozlemevleri.gov.tr)

Last accessed: 24 September 2026.