HATNet Project
A network of automated telescopes detecting transiting exoplanets.
The HATNet project operates six small, fully robotic telescopes known as "HAT" instruments. Its primary aim is to find and study planets beyond our solar system by watching for transits, when a planet crosses in front of its star. The network also tracks bright variable stars. The Center for Astrophysics | Harvard & Smithsonian oversees the project.
The name HAT stands for Hungarian-made Automated Telescope, a nod to its origins with a small team from the Hungarian Astronomical Association. Development began in 1999, and the system has been running continuously since May 2001.
The first prototype, HAT-1, used a 180 mm focal length, 65 mm aperture Nikon telephoto lens paired with a Kodak KAF-0401E chip (512 × 768 pixels, each 9 μm). It was tested at Budapest’s Konkoly Observatory from 2000 to 2001. In January 2001, HAT-1 was moved to the Steward Observatory on Kitt Peak, Arizona, but the trip severely damaged the equipment.
Later telescopes switched to Canon 11 cm diameter f/1.8L lenses, giving a wide 8°×8° field of view. These fully automated units use 2K x 2K CCD sensors. One such instrument operates at the Wise Observatory. A single Linux PC controls each HAT telescope without human oversight, and data is stored in a MySQL database.
Starting in 2009, the HAT-South network added three new sites in Australia, Namibia, and Chile, each with a completely different design. Every site has eight Takahashi Epsilon astrographs (180 mm diameter, f/2.8) mounted in two groups of four, working in parallel with overlapping fields. These use Apogee 4k*4k CCDs. Processing relies on Xenomai-based industrial PCs with 10 TB of storage.
The HAT-1 prototype was built during the undergraduate and early graduate studies of Gáspár Bakos (Eötvös Loránd University, now at Princeton), working at Konkoly Observatory under Dr. Géza Kovács. József Lázár, István Papp, and Pál Sári also played key roles in its development. As of February 2020, over one hundred people had contributed to the project’s seventy published or submitted planet-discovery papers. Bakos, Papp, Lázár, and Sári have been involved in every HAT planet discovery.
- Start year
- 1999
- Fully operational since
- May 2001
- Number of telescopes
- 6
- Total planets discovered
- 134
- Northern planets
- 63
- Southern planets
- 71
- Maintained by
- Center for Astrophysics | Harvard & Smithsonian
Lore & Background
The HAT acronym stands for Hungarian-made Automated Telescope, because it was developed by a small group of Hungarians who met through the Hungarian Astronomical Association. The project started in 1999 and has been fully operational since May 2001. The prototype instrument, HAT-1, was built from a 180 mm focal length and 65 mm aperture Nikon telephoto lens and a Kodak KAF-0401E chip of 512 × 768, 9 μm pixels. Its test period was from 2000 to 2001 at the Konkoly Observatory in Budapest. HAT-1 was transported from Budapest to the Steward Observatory, Kitt Peak, Arizona, USA, in January 2001, but the transportation caused serious damage to the equipment. Later built telescopes use Canon 11 cm diameter f/1.8L lenses for a wide-field of 8°×8°, with 2K x 2K CCD sensors. One HAT instrument operates at the Wise Observatory. HAT is controlled by a single Linux PC without human supervision, and data are stored in a MySQL database.
From 2009, three other locations joined the HATNet with telescopes of completely new design, deployed to Australia, Namibia and Chile. Each system has eight (2*4) joint-mounted, quasi-parallel Takahashi Epsilon (180 mm diameter, f/2.8) astrographs with Apogee 4k*4k CCDs with overlapping fields of view. The processing computers are Xenomai-based industrial PCs with 10 TB of storage. HAT-1 was developed during the undergraduate and first-year graduate studies of Gáspár Bakos at Konkoly Observatory under the supervision of Dr. Géza Kovács, with József Lázár, István Papp and Pál Sári also playing important roles. More than 100 people have contributed to the seventy planet discovery papers published or submitted by the project as of Feb 2020.
Reader's Guide
The HATNet project is notable for its extensive discovery of extrasolar planets using the transit method, having found 134 planets as of the article's data. Sixty-three were found by the northern HATNet project and seventy-one by the southern HATSouth project. A handful of these planets were independently discovered by other groups, particularly the WASP survey. In addition to transiting planets, radial velocity follow-up observations revealed a few additional planetary companions, including HAT-P-13c, which was the first outer planetary or brown-dwarf companion confirmed with a well-characterised orbit for a system with a transiting planet. The project's legacy includes a large collaborative effort: more than 100 people contributed to seventy planet discovery papers as of Feb 2020, with key contributors such as Gáspár Bakos, István Papp, József Lázár, and Pál Sári having contributed to all HAT planet discoveries. The network is maintained by the Center for Astrophysics | Harvard & Smithsonian, and a subset of HATNet light curves are available at the NASA Exoplanet Archive.
Did You Know?
- The prototype HAT-1 was built from a Nikon telephoto lens and a Kodak CCD chip.
- HATNet has discovered 134 extrasolar planets as of the article's data.
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