Time domain astronomy

Last updated

Time domain astronomy is the study of how astronomical objects change with time. Though the study may be said to begin with Galileo's Letters on Sunspots , the term now refers especially to variable objects beyond the Solar System. This may be due to movement or changes in the object itself. Common targets included are supernovae, novas, flare stars, blazars and active galactic nuclei. Visible light time domain studies include HAT-South, the Large Synoptic Survey Telescope, PanSTARRS, SkyMapper, the Wide Angle Search for Planets and the Catalina Real-time Transient Survey.

In radio astronomy the LOFAR is looking for radio transients. Radio time domain studies have long included pulsars and scintillation. Cherenkov Telescope Array, eROSITA, AGILE, Fermi, HAWC, INTEGRAL, MAXI, Swift Gamma-Ray Burst Mission and Space Variable Objects Monitor will look for transients in X-ray and gamma rays. Gamma ray bursts are a well known high energy electromagnetic transient. [1]

Time domain astronomy uses robotic telescopes, automatic classification of transient events, and rapid notification of interested people. Blink comparators have long been used to detect differences between two photographic plates, and image subtraction became more used when digital photography eased the normalization of pairs of images. [2] Time domain work involves storing and transferring a huge amount of data. This includes data mining techniques, classification, and the handling of heterogeneous data. [3]

Historically time domain astronomy has come to include appearance of comets, and cepheid variable. [2] Old astronomical plates exposed from the 1880s through the early 1990s held by the Harvard College Observatory are being digitized by the DASCH project. [4]

Other causes of time variability are asteroids, eclipses, microlensing, planetary transits, and variable stars. [2]

Related Research Articles

Amateur astronomy Hobby of watching the sky and stars

Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, double stars sunspots, or occultations of stars by the Moon or asteroids, or by discovering transient astronomical events, such as comets, galactic novae or supernovae in other galaxies.

X-ray astronomy Branch of astronomy that uses X-ray observation

X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray observation and detection from astronomical objects. X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites. X-ray astronomy is the space science related to a type of space telescope that can see farther than standard light-absorption telescopes, such as the Mauna Kea Observatories, via x-ray radiation.

European Southern Observatory Intergovernmental organization and observatory in Chile

The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is a 16-nation intergovernmental research organisation for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs about 730 staff members and receives annual member state contributions of approximately €162 million. Its observatories are located in northern Chile.

Palomar Observatory Astronomical observatory in Southern California

Palomar Observatory is an astronomical observatory in San Diego County, California, United States, 145 kilometers (90 mi) southeast of Los Angeles, California, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech), located in Pasadena, California. Research time at the observatory is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory (JPL) and Cornell University.

Observational astronomy

Observational astronomy is a division of astronomy that is concerned with recording data about the observable universe, in contrast with theoretical astronomy, which is mainly concerned with calculating the measurable implications of physical models. It is the practice and study of observing celestial objects with the use of telescopes and other astronomical instruments.

La Silla Observatory

La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are located at the site and are partly maintained by ESO. The observatory is one of the largest in the Southern Hemisphere and was the first in Chile to be used by ESO.

Astronomical survey General map or image of a region of the sky with no specific observational target.

An astronomical survey is a general map or image of a region of the sky that lacks a specific observational target. Alternatively, an astronomical survey may comprise a set of many images or spectra of objects that share a common type or feature. Surveys are often restricted to one band of the electromagnetic spectrum due to instrumental limitations, although multiwavelength surveys can be made by using multiple detectors, each sensitive to a different bandwidth.

Konkoly Observatory

Konkoly Observatory is an astronomical observatory owned and operated by the Hungarian Academy of Sciences, located in Budapest, Hungary. It was founded in 1871 by Hungarian astronomer Miklós Konkoly-Thege (1842–1916) as a private observatory, and was donated to the state in 1899. Konkoly Observatory, officially known as MTA CSFK Konkoly Thege Miklós Csillagászati Intézete in Hungarian, is the largest astronomical research institute in Hungary, and hosts the largest telescopes in the country.

Pan-STARRS Multi-telescope astronomical survey

The Panoramic Survey Telescope and Rapid Response System located at Haleakala Observatory, Hawaii, US, consists of astronomical cameras, telescopes and a computing facility that is surveying the sky for moving or variable objects on a continual basis, and also producing accurate astrometry and photometry of already-detected objects. In January 2019 the second Pan-STARRS data release was announced. At 1.6 petabytes, it is the largest volume of astronomical data ever released.

Outline of astronomy Overview of and topical guide to astronomy

The following outline is provided as an overview of and topical guide to astronomy:

Neil Gehrels

Cornelis A. "Neil" Gehrels was an American astrophysicist specializing in the field of gamma-ray astronomy. He was Chief of the Astroparticle Physics Laboratory at NASA's Goddard Space Flight Center from 1995 until his death, and was best known for his work developing the field from early balloon instruments to today's space observatories such as the NASA Swift mission, for which he was the Principal Investigator. He was leading the WFIRST wide-field infrared telescope forward toward a launch in the mid-2020s. He was a member of the National Academy of Sciences and the American Academy of Arts and Sciences.

A transient astronomical event, often shortened by astronomers to a transient, is an astronomical object or phenomenon whose duration may be from seconds to days, weeks, or even several years. This is in contrast to the timescale of the millions or billions of years during which the galaxies and their component stars in our universe have evolved. Singularly, the term is used for violent deep-sky events, such as supernovae, novae, dwarf nova outbursts, gamma-ray bursts, and tidal disruption events, as well as gravitational microlensing, transits, eclipses, and comets. These events are part of the broader topic of time domain astronomy.

The history of gamma-ray began with the serendipitous detection of a gamma-ray burst (GRB) on July 2, 1967, by the U.S. Vela satellites. After these satellites detected fifteen other GRBs, Ray Klebesadel of the Los Alamos National Laboratory published the first paper on the subject, Observations of Gamma-Ray Bursts of Cosmic Origin. As more and more research was done on these mysterious events, hundreds of models were developed in an attempt to explain their origins.

Australian Square Kilometre Array Pathfinder

The Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. It is operated by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and forms part of the Australia Telescope National Facility. Construction commenced in late 2009 and first light was in October 2012.

The Palomar Transient Factory, was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The project completed commissioning in summer 2009, and continued until December 2012. It has since been succeeded by the Intermediate Palomar Transient Factory (iPTF), which itself transitioned to the Zwicky Transient Facility in 2017/18. All three surveys are registered at the MPC under the same observatory code for their astrometric observations.

Joshua Simon Bloom is an American astrophysicist, full professor of astronomy at the University of California, Berkeley, and was the CTO and co-founder of the machine-learning company wise.io. He received a Bachelor of Arts in astronomy and astrophysics and physics from the Harvard College in 1996, an M.Phil from Cambridge University in 1997, and a PhD in astronomy from the California Institute of Technology in 2002. He was a Junior Fellow of the Harvard Society of Fellows from 2002 to 2005. His astronomy research focuses on gamma-ray bursts and other astrophysical transients such as supernovae and tidal disruption events. He is author of the book What Are Gamma-Ray Bursts? published by Princeton University Press in 2011.

Anna N. Żytkow is a Polish astrophysicist working at the Institute of Astronomy of the University of Cambridge. Żytkow and Kip Thorne proposed a model for what is called the Thorne–Żytkow object, which is a star within another star. Żytkow in 2014 was part of the team led by Emily M. Levesque which discovered the first candidate for such an object.


ULTRASAT is an astronomical mini-satellite whose unprecedentedly large field of view, 210 square degrees, will detect and monitor transient astronomical events in the near-ultraviolet spectral region. ULTRASAT will observe a large patch of sky, alternating every six months between the southern and northern hemisphere. The satellite will be launched into geosynchronous orbit in 2023. All ULTRASAT data will be transmitted to the ground in real time. Upon detection of a transient event, ULTRASAT will provide alerts within 20 minutes to other ground-based and space telescopes to be directed to the source for further observation of the event in other wavelength bands.

The Space Variable Objects Monitor (SVOM) is a planned small X-ray telescope satellite under development by China National Space Administration (CNSA) and the French Space Agency (CNES), to be launched in June 2022.


  1. "Multi-Messenger Time Domain Astronomy Conference" . Retrieved 5 May 2013.
  2. 1 2 3 Schmidt, Brian (28 September 2011). "Transient Studies have played a key role in the history of Astronomy" (PDF). Retrieved 5 May 2013.[ permanent dead link ]
  3. Graham, Matthew J.S.; G. Djorgovski; Ashish Mahabal; Ciro Donalek; Andrew Drake; Giuseppe Longo (August 2012). "Data challenges of time domain astronomy". Distributed and Parallel Databases. 30 (5–6): 371–384. arXiv: 1208.2480 . doi:10.1007/s10619-012-7101-7.
  4. Drout, Maria (12 November 2012). "A Big Step Backward for Time Domain Astronomy". astrobites. Retrieved 5 May 2013.