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Topic Review

COROT-7b (previously named COROT-Exo-7b) is an exoplanet orbiting around the star COROT-7, in the constellation Monoceros, at 489 light years from Earth. It was first detected photometrically by the French-led COROT mission and reported in February 2009. Until the announcement of Kepler-10b in January 2011, it was the smallest exoplanet to have its diameter measured, at 1.58 times that of the Earth (which would give it a volume 3.95 times Earth's), and the first potential extrasolar terrestrial planet to be found. The planet has a very short orbital period, revolving around its host star in about 20 hours. Combination of the planet's diameter derived from transit data with the planet's mass derived from radial velocity measurements, meant that the density of CoRoT-7b was about the same as that of Earth and, therefore, that CoRoT-7b was made of rock like Earth and was not a gas giant like Jupiter. The radial velocity observations of CoRoT-7 also detected a second super-Earth, CoRoT-7c, which has a mass 8.4 times that of Earth and orbits every 3.7 days at a distance of 6.9 million km (4.3 million miles).

2.4K
19 Oct 2022

Biography

Wendy Laurel Freedman (born July 17, 1957) is a Canadian-American astronomer, best known for her measurement of the Hubble constant, and as director of the Carnegie Observatories in Pasadena, California, and Las Campanas, Chile. She is now the John & Marion Sullivan University Professor of Astronomy and Astrophysics at The University of Chicago.[1] Her principal research interests are in observa

2.4K
24 Nov 2022

Topic Review

Venus is the second-closest planet to the Sun, orbiting it every 224.7 Earth days. After Earth's Moon, it is the brightest object in the night sky, reaching an apparent magnitude of −4.6. As an inferior planet from Earth it never appears to venture far from the Sun, and its elongation reaches a maximum of 47.8°. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, and is often referred to as the Morning Star or as the Evening Star. A terrestrial planet, it is sometimes called Earth's "sister planet", as the two are similar in size and bulk composition. The planet is covered with an opaque layer of highly reflective clouds and its surface cannot be seen from space in visible light, making it a subject of great speculation until some of its secrets were revealed by planetary science in the 20th century. Venus has the densest atmosphere of the terrestrial planets, consisting mostly of carbon dioxide, and the atmospheric pressure at the planet's surface is 90 times that of the Earth. Venus' surface has been mapped in detail only in the last 20 years. It shows evidence of extensive volcanism, and some of its volcanoes may still be active today. In contrast to the constant crustal movement seen on Earth, Venus is thought to undergo periodic episodes of plate tectonics, in which the crust is subducted rapidly within a few million years separated by stable periods of a few hundred million years. The planet is named after Venus, the Roman goddess of love, and most of its surface features are named after famous and mythological women. The adjective Venusian is commonly used for items related to Venus, though the Latin adjective is the rarely used Venereal; the now-archaic Cytherean is still occasionally encountered.

2.3K
01 Nov 2022

Biography

Sir Fred Hoyle FRS (24 June 1915 – 20 August 2001)[1] was an English astronomer who formulated the theory of stellar nucleosynthesis. He also held controversial stances on other scientific matters—in particular his rejection of the "Big Bang" theory, a term coined by him on BBC radio, and his promotion of panspermia as the origin of life on Earth.[2][3][4] He also wrote science fiction nove

2.3K
17 Nov 2022

Topic Review

Orion Service Module

The Orion service module is the service module component of the Orion spacecraft, serving as its primary power and propulsion component until it is discarded at the end of each mission. In January 2013, NASA announced that the European Space Agency (ESA) will contribute the service module for Artemis 1, replacing the previous design. Based on ESA's Automated Transfer Vehicle (ATV), the new design is also known as the European service module (ESM). The service module supports the crew module from launch through separation prior to reentry. It provides in-space propulsion capability for orbital transfer, attitude control, and high altitude ascent aborts. It provides the water and oxygen needed for a habitable environment, generates and stores electrical power, and maintains the temperature of the vehicle's systems and components. This module can also transport unpressurized cargo and scientific payloads.

2.3K
28 Nov 2022

Topic Review

Andromeda, named after the mythical princess in Greek mythology, is one of the 88 constellations officially recognized by the International Astronomical Union (IAU). Located in the northern celestial hemisphere, Andromeda is renowned for hosting the Andromeda Galaxy (M31), the closest spiral galaxy to our own Milky Way, making it a captivating subject for both amateur stargazers and professional astronomers alike.

2.3K
29 Feb 2024

Topic Review

2020 XL5 is a near-Earth asteroid and Earth trojan discovered by the Pan-STARRS 1 survey at Haleakala Observatory, Hawaii on 12 December 2020. It oscillates around the Sun–Earth L4 Lagrangian point (leading 60°), one of the dynamically stable locations where the combined gravitational force acts through the Sun's and Earth's barycenter. Analysis of 2020 XL5's trojan orbit stability suggests it will remain around Earth's L4 point for at least four thousand years until gravitational perturbations from repeated close encounters with Venus destabilize its trojan configuration. With a diameter about 1.2 km (0.75 mi), 2020 XL5 is the second Earth trojan discovered and is the largest of its kind known, after 2010 TK7.

2.3K
18 Oct 2022

Topic Review

Leo, the Lion, is one of the zodiac constellations, known for its distinctive shape resembling a lion's mane and head. It is one of the oldest recognized constellations, dating back to ancient civilizations such as the Mesopotamians, Egyptians, and Greeks. Leo is home to several bright stars and notable deep-sky objects.

2.2K
15 Mar 2024

Topic Review

The Andromeda Galaxy

Star formation histories of galaxies are critically important for understanding the process of galaxy formation and the structure and contents of galaxies. Star formation can and has been studied in local galaxies for which the stellar populations are resolved and in more distant galaxies for which stars are unresolved, which are instead modeled as populations. Structural components of a galaxy can be resolved at much larger distances. The structural components include those long recognized, such as bulge, disk and halo. More recently recognized structures include separation of disks into thin and thick disk components and stellar streams, as well as recognition of significant numbers of dwarf companion galaxies. Stellar streams are the most recently recognized components of galaxies, mainly using observations of the Milky Way and the Andromeda Galaxy (M31).

2.2K
14 Aug 2023

Topic Review

Hydra, known as the Water Snake, is a prominent constellation located in the southern celestial hemisphere. It is the largest of the 88 modern constellations in terms of area and is best observed from the Southern Hemisphere during the months of February and March.

2.2K
15 Mar 2024

Topic Review

Cetus, known as the Whale, is a large constellation visible in the southern sky. In Greek mythology, Cetus represents the sea monster sent by Poseidon to terrorize the kingdom of Aethiopia, eventually slain by Perseus to rescue Andromeda. As one of the 88 recognized constellations, Cetus holds a special place in the realm of astronomy and mythology.

2.2K
08 Mar 2024

Topic Review

Standard and Alternative Cosmology

The Standard and The Alternative Cosmological Models, Distances Calculation to Galaxies without Hubble Constant For the alternative cosmological models considered in the extended version of this entry, the distances are calculated for galaxies without using the Hubble constant. This process is mentioned in the second narrative, and described in detail in the third narration. According to the third narrative, as the density of the relativistic mass of the universe decreases while the universe expands, new matter is created by a phase transition process which results in a continuously constant ordinary density of matter. While the universe develops on the basis of this postulate of the emergence of new matter, it is "assumed that matter arises as a result of such a phase transition of dark energy into both new dark and visible matter. It is somewhat irrelevant how we describe dark energy, calling it aether, or vice versa, the changing of aether into dark energy. It should be clear to everyone that this renaming does not change the essence of this phase transition phenomena. It should be noted that, unlike all well‐known geometric models of the Euclidean space of our existence, this phase transition of dark energy into matter would accordingly be a stereographic projection of a three‐dimensional surface on to a four‐dimensional globe.

2.2K
29 Oct 2020

Topic Review

Scorpius, known as "the Scorpion," is a striking constellation visible in the southern celestial hemisphere during the summer months. With its distinctive shape resembling a scorpion's curved tail, Scorpius is one of the most recognizable constellations in the night sky.

2.2K
15 Mar 2024

Topic Review

Volcanology of Venus

The surface of Venus is dominated by volcanic features and has more volcanoes than any other planet in the Solar System. It has a surface that is 90% basalt, and about 65% of the planet consists of a mosaic of volcanic lava plains, indicating that volcanism played a major role in shaping its surface. There are more than 1,000 volcanic structures and possible periodic resurfacing of Venus by floods of lava. The planet may have had a major global resurfacing event about 500 million years ago, from what scientists can tell from the density of impact craters on the surface. Venus has an atmosphere rich in carbon dioxide, with a density that is 90 times greater than Earth's atmosphere. Even though there are over 1,600 major volcanoes on Venus, none are known to be erupting at present and most are probably long extinct. However, radar sounding by the Magellan probe revealed evidence for comparatively recent volcanic activity at Venus's highest volcano Maat Mons, in the form of ash flows near the summit and on the northern flank. Although many lines of evidence suggest that Venus is likely to be volcanically active, present-day eruptions at Maat Mons have not been confirmed. Nevertheless, other more recent studies, in January 2020, suggests Venus is currently volcanically active.

2.2K
22 Nov 2022

Topic Review

Canis Minor, Latin for "Lesser Dog," is a small constellation in the northern celestial hemisphere. Named for one of the hunting dogs of Orion in Greek mythology, Canis Minor is characterized by its two brightest stars, Procyon and Gomeisa, which shine brightly in the night sky.

2.2K
29 Feb 2024

Topic Review

Phoenix, a constellation in the southern celestial hemisphere, is named after the mythical bird that cyclically regenerates or is reborn from its own ashes. The constellations Phoenix, Grus, Pavo and Tucana, are known as the Southern Birds.

2.2K
15 Mar 2024

Topic Review

Cepheus is a northern constellation named after the mythical king of Aethiopia in Greek mythology. Positioned in the celestial northern hemisphere, it is recognizable for its distinctive shape resembling a house with a peaked roof. Cepheus is home to several notable deep-sky objects, including the famous variable star Delta Cephei, which gave its name to a class of pulsating stars known as Cepheid variables.

2.2K
29 Feb 2024

Biography

Peter Goldreich

Peter Goldreich (born July 14, 1939) is an United States astrophysicist whose research focuses on celestial mechanics, planetary rings, helioseismology and neutron stars.[1] He is currently the Lee DuBridge Professor of Astrophysics and Planetary Physics at California Institute of Technology. Since 2005 he has also been a professor at the Institute for Advanced Study in Princeton, New Jersey.[2]

2.1K
18 Nov 2022

Topic Review

Auriga, an IAU-recognized constellation, lies in the northern celestial hemisphere. Notable for its pentagonal shape, it encompasses several bright stars, including Capella. This constellation is visible during winter and contains various deep-sky objects like star clusters and nebulae.

2.1K
29 Feb 2024

Topic Review

Camelopardalis, recognized by the International Astronomical Union (IAU), is a constellation located in the northern celestial hemisphere. Its name is derived from the Latin word for "giraffe," reflecting its association with this graceful and majestic creature.

2.1K
29 Feb 2024

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