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In 1968 Shirley Chisholm became the first Black woman elected to the United States Congress. In 1972 she launched a campaign for the Democratic presidential nomination, breaking another political barrier.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
 Size comparison of WASP-18b with Jupiter. | |
| Discovery[1] | |
|---|---|
| Discovered by | Hellier et al. (SuperWASP) |
| Discovery date | August 27, 2009 |
| Transit (including secondary eclipses) | |
| Orbital characteristics[2] | |
| 0.02041+0.00015 −0.00014 au (3,053,000 km) | |
| Eccentricity | 0.0051+0.0070 −0.0037[3] |
| 0.941452379(16) days (22.6 hours) | |
| Inclination | 84.08°±0.17° |
| −85°+72° −96°[3] | |
| Semi-amplitude | 1,814.73(70) m/s[4] |
| Star | WASP-18 |
| Physical characteristics | |
| 1.1926±0.0077 RJ[2] | |
| Mass | 10.20±0.35 MJ[3] |
Mean density | 6.6+1.2 −1.1 g/cm3[3] |
| Albedo | Geometric: 0.027±0.011[2] |
| Temperature | 3,061 ± 29 K (2,787.8 ± 29.0 °C; 5,050.1 ± 52.2 °F)[2] |
WASP-18b is an exoplanet that is notable for having an orbital period of less than one day. It has a mass equal to 10 Jupiter masses,[1] just below the boundary line between planets and brown dwarfs (about 13 Jupiter masses). Due to tidal deceleration, it is expected to spiral toward and eventually merge with its host star, WASP-18, in less than a million years.[1] The planet is approximately 3.1 million km (1.9 million mi; 0.021 AU) from its star, which is about 400 light-years (120 parsecs) from Earth. A team led by Coel Hellier, a professor of astrophysics at Keele University in England, discovered the exoplanet in 2009.[1]
Scientists at Keele and at the University of Maryland are working to understand whether the discovery of this planet so shortly before its expected demise (with less than 0.1% of its lifetime remaining) was fortuitous, or whether tidal dissipation by WASP-18 is actually much less efficient than astrophysicists typically assume.[1][5] Observations made over the next decade should yield a measurement of the rate at which WASP-18b's orbit is decaying.[6] The closest example of a similar situation in the Solar System is Mars' moon Phobos. Phobos orbits Mars at a distance of only about 9,000 km (5,600 mi), 40 times closer than the Moon is to the Earth[7] and is expected to be destroyed in about eleven million years.[8]
A study in 2012, utilizing the Rossiter–McLaughlin effect, determined that the planetary orbit is well aligned with the equatorial plane of the star, with a misalignment equal to 13±7°.[9]
The planet's dayside temperature, as measured in 2020, is 3,029 ± 50 K (2,755.8 ± 50.0 °C; 4,992.5 ± 90.0 °F).[10] A 2023 study found an average dayside temperature of 2,781+25
−13 K (2,508 °C; 4,546 °F).[11] It has been theorized that highly irradiated ultra-hot Jupiters like WASP-18b have large variations in atmospheric temperature and chemistry as a function of longitude, latitude and altitude. WASP-18b was observed with the Near Infrared Imager and Slitless Spectrograph instruments on JWST creating a resolved atmosphere in multiple dimensions. Mapping confirmed theoretical models revealing a weaker longitudinal temperature gradient. It also indicated the importance of hydrogen dissociation and/or nightside clouds role in shaping thermal emission on the global scale.[8]
A 2017 study detected carbon monoxide in the planet's atmosphere, without signs of water vapor.[12][13] However, in 2023, the James Webb Space Telescope detected water vapor in the planet's atmosphere.[11][14]
There are two thermally distinct identified regions on the planets atmosphere. The first is the "hotspot" surrounding the substellar point. near the dayside limbs. The hotspot region shows a strongly inverted thermal structure due to the presence of optical absorbers and a water abundance marginally lower than average. The second region is a "ring" near the dayside limb. This region shows colder temperatures and poorly constrained chemical abundances.[8]
Media related to WASP-18b at Wikimedia Commons
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
WASP-18b is an exoplanet that is notable for having an orbital period of less than one day. It has a mass equal to 10 Jupiter masses, just below the boundary line between planets and brown dwarfs (about 13 Jupiter masses). Due to tidal deceleration, it is expected to spiral toward and eventually merge with its host star, WASP-18, in less than a million years. The planet is approximately 3.1 million km (1.9 million mi; 0.021 AU) from its star, which is about 400 light-years (120 parsecs) from Earth. A team led by Coel Hellier, a professor of astrophysics at Keele University in England, discovered the exoplanet in 2009. Scientists at Keele and at the University of Maryland are working to understand whether the discovery of this planet so shortly before its expected demise (with less than 0.1% of its lifetime remaining) was fortuitous, or whether tidal dissipation by WASP-18 is actually much less efficient than astrophysicists typically assume. Observations made over the next decade should yield a measurement of the rate at which WASP-18b's orbit is decaying. The closest example of a similar situation in the Solar System is Mars' moon Phobos. Phobos orbits Mars at a distance of only about 9,000 km (5,600 mi), 40 times closer than the Moon is to the Earth and is expected to be destroyed in about eleven million years. A study in 2012, utilizing the Rossiter–McLaughlin effect, determined that the planetary orbit is well aligned with the equatorial plane of the star, with a misalignment equal to 13±7°.
WASP-33b is an extrasolar planet orbiting the star HD 15082. It was the first transiting planet discovered to orbit a Delta Scuti variable star. With a semimajor axis of 0.026 AU (3.9 million km; 2.4 million mi) and a mass likely greater than Jupiter's, it belongs to the hot Jupiter class of planets.
WASP-43b, formally named Astrolábos, is a transiting planet in orbit around the young, active, and low-mass star WASP-43 in the constellation Sextans. The planet is a hot Jupiter with a mass twice that of Jupiter, but with a roughly equal radius. WASP-43b was flagged as a candidate by the SuperWASP program, before they conducted follow-ups using instruments at La Silla Observatory in Chile, which confirmed its existence and provided orbital and physical characteristics. The planet's discovery was published on April 14, 2011. WASP-43b has an orbital period of approximately 0.8 days (19.2 hours), which at the time of discovery was the third-shortest known, surpassed only by WASP-19b and WASP-47e. At the time of its discovery, the size of WASP-43b's orbit was the smallest known for a hot Jupiter, probably due to its host star's low mass.
WASP-18 is a magnitude 9 star located 400 light-years (120 parsecs) away in the Phoenix constellation of the Southern Hemisphere. It has a mass of 1.29 solar masses. The star, although similar to the Sun in terms of overall contents of heavy elements, is depleted in carbon. The carbon to oxygen molar ratio of 0.23±0.05 for WASP-18 is well below the solar ratio of 0.55. There is a red dwarf companion star at a separation of 3,519 AU.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Joe Louis.
