Sagittarius Window Eclipsing Extrasolar Planet Search
Encyclopedia
The Sagittarius Window Eclipsing Extrasolar Planet Search, or SWEEPS, was a 2006 astronomical survey project using the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...

's Advanced Camera for Surveys - Wide Field Channel to monitor 180,000 stars for seven days to detect extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...

s via the transit method.

Area examined

The stars that were monitored in this astronomical survey were all located in the Sagittarius-I Window, a rare transparent
Transparency and translucency
In the field of optics, transparency is the physical property of allowing light to pass through a material; translucency only allows light to pass through diffusely. The opposite property is opacity...

 view to the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...

's central bulge stars in the Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 as our view to most of the galaxy's central stars is blocked by lanes of dust
Dark nebula
A dark nebula is a type of interstellar cloud that is so dense that it obscures the light from the background emission or reflection nebula or that it blocks out background stars . The extinction of the light is caused by interstellar dust grains located in the coldest, densest parts of larger...

. These stars in the galaxy's central bulge region are approximately 27,000 light years from Earth.

Planets discovered

Sixteen candidate planets were discovered with orbital periods ranging from 0.6 to 4.2 day
Day
A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...

s. Planets with orbital periods less than 1.2 days have not previously been detected, and have been dubbed "ultra-short period planets" (USPPs) by the search team. USPPs were discovered only around low-mass stars, suggesting that larger stars destroyed any planets orbiting so closely or that planets were unable to migrate as far inward around larger stars.

Planets were found with roughly the same frequency of occurrence as in the local neighborhood of Earth.

SWEEPS-4 and SWEEPS-11 orbited stars that were sufficiently visually distinct from their neighbors that followup observations using the radial velocity method were possible, allowing their masses to be determined.

This table is constructed from information obtained from the Extrasolar Planets Encyclopedia and SIMBAD
SIMBAD
SIMBAD is an astronomical database of objects beyond the Solar System...

 databases that reference the Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...

 article as their source.
Star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

Constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

Right
ascension
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...

Declination
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...

App.
mag.
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...

Distance (ly) Spectral
type
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...

Planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

Mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...


(MJ
Jupiter mass
Jupiter mass , is the unit of mass equal to the total mass of the planet Jupiter . Jupiter mass is used to describe masses of the gas giants, such as the outer planets and extrasolar planets. It is also used in describing brown dwarfs....

)
Radius
Radius
In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its...


(RJ)
Orbital
period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...


(d
Day
A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...

)
Semimajor
axis
(AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....

)
Orbital
eccentricity
Inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...


(°
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...

)
Discovery
year
SWEEPS J175853.29-291233.5 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
22.2 ~22000 SWEEPS-01 ? 1.01 1.56 0.025 ? 86+ 2006
SWEEPS J175853.38-291217.8 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
25.1 ~22000 SWEEPS-02 ? 1.37 0.912 0.015 ? 86+ 2006
SWEEPS J175853.57-291144.1 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
22.5 ~22000 SWEEPS-03 ? 0.87 1.27 0.021 ? 86+ 2006
SWEEPS J175853.92−291120.6  Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
18.8 ~22000 SWEEPS-04  <3.8 0.81 4.2 0.055 ? 87+ 2006
SWEEPS J175854.60-291128.2 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
23.9 ~22000 SWEEPS-05 ? 1.09 2.313 0.030 ? 87+ 2006
SWEEPS J175857.29-291253.4 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
19.5 ~22000 SWEEPS-06 ? 0.82 3.039 0.042 ? 86+ 2006
SWEEPS J175857.69-291114.5 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
21.5 ~22000 SWEEPS-07 ? 0.9 1.747 0.027 ? 86+ 2006
SWEEPS J175859.24-291328.7 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
21.7 ~22000 SWEEPS-08 ? 0.98 0.868 0.017 ? 84+ 2006
SWEEPS J175859.60-291211.8 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
22.5 ~22000 SWEEPS-09 ? 1.01 1.617 0.025 ? 86+ 2006
SWEEPS J175902.00-291323.7
SWEEPS-10
|- style="vertical-align: top;"SWEEPS-10 is, as of June 2007, the planet candidate with the shortest orbital period yet found. The planet orbits the star SWEEPS J175902.00−291323.7 located in the Galactic bulge at a distance of approximately 22000 light years from Earth...

 
Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
26.2 ~22000 SWEEPS-10
SWEEPS-10
|- style="vertical-align: top;"SWEEPS-10 is, as of June 2007, the planet candidate with the shortest orbital period yet found. The planet orbits the star SWEEPS J175902.00−291323.7 located in the Galactic bulge at a distance of approximately 22000 light years from Earth...

 
? 1.24 0.424 0.008 ? 84+ 2006
SWEEPS J175902.67−291153.5
SWEEPS-11
SWEEPS-11 is an extrasolar planet orbiting the star SWEEPS J175902.67−291153.5 in the constellation Sagittarius approximately 22000 light years away from the Solar System...

 
Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
19.83 ~22000 SWEEPS-11
SWEEPS-11
SWEEPS-11 is an extrasolar planet orbiting the star SWEEPS J175902.67−291153.5 in the constellation Sagittarius approximately 22000 light years away from the Solar System...

 
9.7 1.13 1.796 0.03 ? 84+ 2006
SWEEPS J175904.44-291317.1 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
21.8 ~22000 SWEEPS-12 ? 0.91 2.952 0.038 ? 87+ 2006
SWEEPS J175905.95-291305.6 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
21.38 ~22000 SWEEPS-13 ? 0.78 1.684 0.027 ? 86+ 2006
SWEEPS J175907.56-291039.8 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
22.38 ~22000 SWEEPS-14 ? 0.93 2.965 0.037 ? 87+ 2006
SWEEPS J175907.64-291023.7 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
25.66 ~22000 SWEEPS-15 ? 1.37 0.541 0.010 ? 84+ 2006
SWEEPS J175908.44-291140.6 Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

 
23.78 ~22000 SWEEPS-16 ? 1.4 0.969 0.017 ? 85+ 2006

See also

  • Optical Gravitational Lensing Experiment
    Optical Gravitational Lensing Experiment
    The Optical Gravitational Lensing Experiment or OGLE is a Polish astronomical project based at the University of Warsaw that is chiefly concerned with discovering dark matter using the microlensing technique. Since the project began in 1992, it has discovered several extrasolar planets as a side...

     or OGLE also examines the galactic bulge for planets.
  • Baade's Window
    Baade's Window
    Baade's Window is an area of the sky with relatively low amounts of interstellar "dust" along the line of sight from the Earth. This area is considered an observational "window" as the normally obscured Galactic Center of the Milky Way is visible in this direction. It is named for astronomer Walter...


External links

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