Astronomy and Astrophysics: Facts
Here is a list of some curiosities of astronomy and astrophysics. From our solar system to interstellar space.
Pluto: Pluto is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune. It was the first Kuiper belt object to be discovered. Like other Kuiper belt objects, Pluto is primarily made of ice and rock and is relatively small—about one-sixth the mass of the Moon and one-third its volume. It has a moderately eccentric and inclined orbit during which it ranges from 30 to 49 astronomical units or AU (4.4–7.4 billion km) from the Sun.
Great Red Spot: The Great Red Spot is a persistent zone of high pressure, producing an anticyclonic storm on the planet Jupiter, 22° south of the equator. It has been continuously observed for 187 years, since 1830. Earlier observations from 1665 to 1713 are believed to have been the same storm; if this is correct, it has existed for more than 350 years.
Moons of Jupiter: There are 69 known moons of Jupiter. This gives Jupiter the largest number of moons with reasonably stable orbits of any planet in the Solar System.
Uranus: Axial tilt: The Uranian axis of rotation is approximately parallel with the plane of the Solar System, with an axial tilt of 97.77° (as defined by prograde rotation). This gives it seasonal changes completely unlike those of the other planets. Near the solstice, one pole faces the Sun continuously and the other faces away. Only
VFTS 102: VFTS 102 is a star located in the Tarantula nebula, a star forming region in the Large Magellanic Cloud, a satellite galaxy of the Milky Way.
The peculiarity of this star is its projected equatorial velocity of ~600 km/s (about 2.000.000 km/h), making it the fastest rotating massive star known. The resulting centrifugal force tends to flatten the star; material can be lost in the loosely bound equatorial regions, allowing for the formation of a disk. The spectroscopic observations seem to confirm this, and the star is classified as Oe, possibly due to emission from such an equatorial disk of gas.
Black Holes: Monsters in Space: This artist’s concept illustrates a supermassive black hole with millions to billions times the mass of our sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies. (Smaller black holes also exist throughout galaxies.) In this illustration, the supermassive black hole at the center is surrounded by matter flowing onto the black hole in what is termed an accretion disk. This disk forms as the dust and gas in the galaxy falls onto the hole, attracted by its gravity.
Saturn’s hexagon: Saturn’s hexagon is a persisting hexagonal cloud pattern around the north pole of Saturn, located at about 78°N. The sides of the hexagon are about 13,800 km (8,600 mi) long, which is more than the diameter of Earth (about 12,700 km (7,900 mi)).
Gravitational lens: A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer, that is capable of bending the light from the source as the light travels towards the observer. This effect is known as gravitational lensing, and the amount of bending is one of the predictions of Albert Einstein’s general theory of relativity.
Quasar: A quasar is an active galactic nucleus of very high luminosity. A quasar consists of a supermassive black hole surrounded by an orbiting accretion disk of gas. As gas in the accretion disk falls toward the black hole, energy is released in the form of electromagnetic radiation. Quasars emit energy across the electromagnetic spectrum and can be observed at radio, infrared, visible, ultraviolet, and X-ray wavelengths.
Stretching SpaceTime: According to general relativity, the sun’s mass makes an imprint on the fabric of spacetime that keeps the planets in orbit. A neutron star leaves a greater mark. But a black hole is so dense that it creates a pit deep enough to prevent light from escaping.
Source: Wikipedia, NASA & ESO
Image credit: NASA, JPL, New Horizons, Keck Observatory, Hubble, Chandra, Kevin Gill, James Provost