The Swift UVOT Photometric System
Encyclopedia
In astronomical photometry
, the Ultraviolet and Optical Telescope (UVOT) on the Swift Gamma-Ray Burst Mission
observes astronomical objects in its 17-by-17 arc minute field of view through one of several filters or grisms. The seven filters, which are similar to those on the XMM-Newton
-OM instrument, cover the near-ultraviolet and optical range. The brightness of an object observed in the three optical filters, called u, b, and v, can be converted into the more common Morgan-Johnson (see the UBV photometric system
) magnitudes.
The three ultraviolet filters probe a spectral region that is not observable from the ground.
Although the main mission is to chase gamma-ray bursts as soon as they occur, many other transient celestial sources and other objects in the field of view are being measured.
The filters, not being like any other Photometric system
in use from the ground or in space, give unique photometric measurements. Their response has been defined as the UVOT photometric system, as outlined by .
Photometry (astronomy)
Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation...
, the Ultraviolet and Optical Telescope (UVOT) on the Swift Gamma-Ray Burst Mission
Swift Gamma-Ray Burst Mission
The Swift Gamma-Ray Burst Mission consists of a robotic spacecraft called Swift, which was launched into orbit on 20 November 2004, 17:16:00 UTC on a Delta II 7320-10C expendable launch vehicle. Swift is managed by the NASA Goddard Space Flight Center, and was developed by an international...
observes astronomical objects in its 17-by-17 arc minute field of view through one of several filters or grisms. The seven filters, which are similar to those on the XMM-Newton
XMM-Newton
The XMM-Newton is an orbiting X-ray observatory launched by ESA in December 1999 on a Ariane 5 rocket...
-OM instrument, cover the near-ultraviolet and optical range. The brightness of an object observed in the three optical filters, called u, b, and v, can be converted into the more common Morgan-Johnson (see the UBV photometric system
UBV photometric system
UBV photometric system, also called the Johnson system , is a wide band photometric system for classifying stars according to their colors. It is the first known standardized photoelectric photometric system. The letters U, B, and V stand for ultraviolet, blue, and visual magnitudes, which are...
) magnitudes.
The three ultraviolet filters probe a spectral region that is not observable from the ground.
Although the main mission is to chase gamma-ray bursts as soon as they occur, many other transient celestial sources and other objects in the field of view are being measured.
The filters, not being like any other Photometric system
Photometric system
In astronomy, a Photometric system is a set of well-defined passbands , with a known sensitivity to incident radiation. The sensitivity usually depends on the optical system, detectors and filters used. For each photometric system a set of primary standard stars is provided.The first known...
in use from the ground or in space, give unique photometric measurements. Their response has been defined as the UVOT photometric system, as outlined by .