The Livermore Optical Transient Imaging System, or LOTIS, is an automated

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...

designed to slew very rapidly to the location of

gamma-ray burst In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milli ...

s (GRBs), to enable the simultaneous measurement of optical counterparts. Since GRBs can occur anywhere in the sky, are often poorly localized, and fade very quickly, this implies very rapid slewing (less than 10 sec) and a wide

field of view The field of view (FoV) is the extent of the observable world that is seen at any given moment. In the case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation. Humans a ...

(greater than 15 degrees). To achieve the needed response time, LOTIS was fully automated and connected via Internet socket to the

Gamma-ray Burst Coordinates Network The gamma-ray burst coordinates network (GCN) is a system that distributes information about the location of a gamma-ray burst (GRB), called ''notices'', when a burst is detected by various spacecraft. The GCN also automatically receives and dist ...

. This network analyzes telemetry from satellite such as

HETE-2 High Energy Transient Explorer 2 (HETE-2; also known as Explorer 79) was a NASA astronomical satellite with international participation (mainly Japan and France). The satellite bus for the first HETE-1 was designed and built by AeroAstro, Inc ...

and

Swift Gamma-Ray Burst Mission Neil Gehrels Swift Observatory, previously called the Swift Gamma-Ray Burst Explorer, is a NASA three-telescope space observatory for studying gamma-ray bursts (GRBs) and monitoring the afterglow in X-ray, and UV/Visible light at the location o ...

and delivers GRB coordinate information in real-time. The optics were built from 4 commercial tele-photo lenses of 11 cm aperture, with custom 2048 X 2048 CCD cameras, and could view a 17.6 X 17.6 degree field. LOTIS started routine operation in October 1996, with a limiting magnitude M_v≈11.5 . In March 1998 it was upgraded with cooled cameras, resulting in a limiting sensitivity of M_v≈14. It was in operation until at least 2001, but never successfully detected the optical counterpart of a GRB, though it did set upper limits. By 2001, the 4 cameras had been co-aligned and two of them had added filters. In the idle time between GRB triggers, LOTIS systematically surveyed the entire available sky every night for new optical transients. LOTIS was succeeded by another robotic telescope with a larger mirror but smaller field of view, called Super-LOTIS.

Super-LOTIS

Super-LOTIS is the second incarnation of the Livermore Optical Transient Imaging System, located at the

Steward Observatory Steward Observatory is the research arm of the Department of Astronomy at the University of Arizona (UArizona). Its offices are located on the UArizona campus in Tucson, Arizona (US). Established in 1916, the first telescope and building were f ...

on Kitt Peak. It is an automated

designed to slew very rapidly to the location of

s (GRBs), to enable the simultaneous measurement of optical counterparts. GRBs can occur anywhere in the sky, fade very quickly, and were initially poorly localized, so the original LOTIS needed very rapid slewing (less than 10 sec) and an extremely wide

(greater than 15 degrees). However, this wide field of view meant it could not see faint sources, and only the brightest GRB afterglows could be studied. Later satellites such as

, and

BATSE The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with photon energy, energies from 20 kElectronvolt#Properties, eV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main tele ...

detector of the

Compton Gamma Ray Observatory The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with energies from 20 k eV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main telescopes in one spacecraft, covering X- ...

, delivered much more accurate GRB coordinates in real-time. This enabled the construction of Super-LOTIS, based upon a

Boller and Chivens Boller and Chivens was an American manufacturer of high-quality telescopes and spectrographs headquartered in South Pasadena, California. History Founded about 1946 by Harry Berthold Boller (1915-1997) and Clyde Cuthbertson Chivens (1915-2008). ...

0.6 meter telescope, with a much smaller field of view (originally 51' by 51'), but much deeper imaging. After a few years of operation in this mode (2000 to 2003), the

was launched in 2004 providing even smaller error boxes. The super-LOTIS optics were modified again, now with a 17' by 17' field of view at the secondary focus, and a simultaneous visible/NIR camera. To achieve the needed response time, Super-LOTIS is fully automated and connected via Internet socket to the

. It is still in operation as of 2012. Since GRB searches only occupy a small fraction of the possible observing time, Super-LOTIS is also used for supernova searches and general astronomy.

References

* {{cite journal , title=The Robotic Super-LOTIS Telescope: Results & Future Plans , author=Williams, GG , author2=Milne, PA , author3=Park, HS , author4=Barthelmy, SD , author5=Hartmann, DH , author6=Updike, A , author7=Hurley, K , name-list-style=amp , arxiv=0803.0021 , date=2008 , doi=10.1063/1.2943525 , journal=AIP Conference Proceedings , volume=1000 , pages=535–538 , s2cid=118333543 Robotic telescopes Gamma-ray astronomy Kitt Peak National Observatory Optical telescopes

Super-LOTIS

See also

References