A measure of the rate at which the Universe is expanding. The Hubble Constant relates the apparent recession velocity of a galaxy to its distance from the Milky Way. The precise value of the Hubble Constant is unknown, although independent measurements have established the value of this constant to be between 50 and 80 kilometres per second per mega parsec (in other words, for every megaparsec, the object's velocity of recession increases by 50 to 80 km/s).
The numerical factor, usually denoted H, that describes the rate of expansion of the universe. It is the proportionality constant in the Hubble law v ~Hd, which relates the speed of recession of a galaxy to its distance . The present value of H has recently become fairly well known; estimates range between 47 and 63 km/sec Y Mpc, giving an age of the universe around 14 billion years. A to F | G to L | M to R | S to Z
Constant of proportionality (H) that appears in the Hubble law of recession of for galaxies. Its presently determined value is about 17km/s/megalight year.
The Hubble Constant, or H0 features in Hubble's Law. Hubble's Law is a mathematical expression which says that the further away an object is from Earth, the faster it's moving away from us.
The proportionality factor between the distance of a galaxy and the velocity with which it recedes; currently, its best estimate is 22 kilometers/second/million light-years.
Or H0, the ratio of velocity (v) to distance (D) in the expansion of the Universe, so v = H0D. The "0" [pronounced "naught"] on H0 means the current value, since the Hubble "constant" changes with time (but it is the same everywhere in the Universe at a given time).
A measure of the rate of expansion of the Universe; current estimates are about 70 km/s/megaparsec.
The expansion rate of the universe as measured in kilometers per second per megaparsec. Observations with the Hubble Space Telescope indicate an expansion rate of approximately 65 kilometers per second per megaparsec. However, recent observations suggest the expansion rate may be accelerating.
The constant H0—discovered in 1925 by Edwin Hubble—determines the relationship between the distance to a galaxy and its velocity of recession due to the expansion of the Universe. After many years in which the Hubble constant was only known to be somewhere between 50 and 100 km/s/Mpc (kilometers per second per megaparsec) it has recently been determined by the Hubble Space Telescope's Key Project team to be 70 km/s/Mpc ± 7 km/s/Mpc. Advances in cosmology have shown that since the Universe is self gravitating, H0 is not truly constant. Astronomers thus seek its current value.
The value which describes the rate at which the universe is currently expanding. The Hubble constant helps to determine the size and age of the universe, and is also used to convert the redshift of a galaxy into a distance estimate. The Hubble constant is not known precisely but it is somewhere in the range of 60 to 80 km/s/Mpc.
or Ho, the ratio of velocity to distance in the expansion of the Universe, so v = HD. The "o" [pronounced "naught"] on Ho means the current value, since the Hubble "constant" changes with time (but it is the same everywhere in the Universe at a given time). The measured value of Ho has also changed dramatically since even before Hubble's work, as shown in Huchra's Ho history.
the value that expresses the expansion rate of the universe and is equal to the recessional velocity of a galaxy divided by the distance to the galaxy; usually expressed in kilometers per second per megaparsec (3.26 million light-years).
Ratio of outward speed of galaxies to their distances from Earth.
The ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer; the reciprocal of the Hubble constant is approximately the age of the universe.
The constant of proportionality which gives the relation between apparent recessional velocity and distance in Hubble's law.
The proportionality constant relating velocity and distance in the Hubble law; the value, now around 75 km/s/Mpc, changes with time as the Universe expands.
slope of the line relating the speed of the galaxies away from each other and their distance apart from each other.
Constant of proportionality between the velocities of remote galaxies and their distances. The Hubble constant is thought to lie in the range of 15 to 30 km/s per million LY.
The Hubble Constant, H is the number (not actually a constant) which shows the rate at which the universe is expanding. It determines the relationship between how far a galaxy is from us and how fast it is receding from us (because of the expansion of the Universe). H is between 50 and 100 km/s/mparsec. Hubble's constant can be used to estimate the size and age of the Universe (Hubble Time). It was formulated by E. P. Hubble in 1925.
A measure of the rate of expansion of the universe. The average value of velocity of recession divided by distance. Presently believed to be between 50 and 100 km/s/Mpc.