The accretion rate of these water droplets is another factor in the hailstone ’ s growth.

The recurrence interval for a nova is less dependent on the white dwarf's accretion rate than on its mass ; with their powerful gravity, massive white dwarfs require less accretion to fuel an outburst than lower-mass ones.

This means that it is possible that most galaxies, including our own Milky Way, have gone through an active stage ( appearing as a quasar or some other class of active galaxy depending on black hole mass and accretion rate ) and are now quiescent because they lack a supply of matter to feed into their central black holes to generate radiation.

Simulations have shown that the presence of a binary companion can actually improve the rate of planet formation within stable orbital zones by " stirring up " the protoplanetary disk, increasing the accretion rate of the protoplanets within.

During accretion, the settled corals display an increased growth rate, size and density, but after the process is complete, growth rate and density return to levels comparable to natural growth, and are about the same size or slightly smaller.

is the accretion rate, in units of,

The ADAF solutions usually require that the accretion rate is smaller than a few percent of the Eddington limit.

When the accretion rate is sub-Eddington and the opacity very high, the standard thin accretion disc is formed.

When the accretion rate is sub-Eddington and the opacity very low, an ADAF is formed.

Most X-ray bursters have irregular periods, which can be on the order of a few hours to many months, depending on factors such as the masses of the stars, the distance between the two stars, the rate of accretion, and the exact composition of the accreted material.

At this stage the rate of accretion is proportional to R < sup > 2 </ sup >, which is derived from the geometrical cross-section of an oligarch.

The specific accretion rate is proportional to ; and it declines with the mass of the body.

Tidal flats gain elevation relative to sea level by sediment accretion, and subsequently the rate and duration of tidal flooding decreases so that vegetation can colonize on the exposed surface.

The factors and processes that influence the rate and spatial distribution of sediment accretion within the salt marsh are numerous.

Cultivation of land upstream from the salt marsh can introduce increased silt inputs and raise the rate of primary sediment accretion on the tidal flats, so that pioneer species can spread further onto the flats and grow rapidly upwards out of the level of tidal inundation.

* The number of fellows is restricted either to a total number or to a rate of accretion

However, when contacted by Scientific American, Dr Sion said that the term " soon " in the press announcement meant that " At the accretion rate we derived, the white dwarf in T Pyxidis will reach the Chandrasekhar Limit in ten million years.

The transfer of angular momentum from this accretion event can theoretically increase the rotation rate of the pulsar to hundreds of times a second, as is observed in millisecond pulsars.

If the above liability, for example an asset retirement obligation, had a discount rate of 10 %, accretion expense in Yr. 1 would be $ 65 and the PV of the liability at the end of Yr. 1 would be $ 715.

The accretion rate varies with growth of the fish – often less growth in winter and more in summer – which results in the appearance of rings that resemble tree rings.

Many chondritic asteroids also contained significant amounts of water, possibly due to the accretion of ice along with rocky material.

They include accretion under water, but apparent pores in the particles make alternative possibilities of meteor impacts or volcanic eruptions more likely origins, he said.

On October 20, 2011, it was reported that oceans-worth of cold water vapor had been discovered in the accretion disc of a young star.

Matter falling onto a black hole can form an accretion disk heated by friction, forming some of the brightest objects in the universe.

The matter accreting onto the black hole is unlikely to fall directly in, but will have some angular momentum around the black hole that will cause the matter to collect in an accretion disc.

As described above, the collapse of a rotating cloud of gas and dust leads to the formation of an accretion disk through which matter is channeled onto a central protostar.

In the past, it was thought that this radiation pressure might be substantial enough to halt accretion onto the massive protostar and prevent the formation of stars with masses more than a few tens of solar masses.

Recent theoretical work has shown that the production of a jet and outflow clears a cavity through which much of the radiation from a massive protostar can escape without hindering accretion through the disk and onto the protostar.

The accretion disk may be prone to an instability leading to dwarf nova outbursts, when a portion of the disk material falls onto the white dwarf ; the cataclysmic outbursts occur when the density and temperature at the bottom of the accumulated hydrogen layer rise high enough to ignite nuclear fusion reactions, which rapidly convert the hydrogen layer to helium.

For a long time it has been argued that AGN must be powered by accretion onto massive black holes ( with masses between 10 < sup > 6 </ sup > and 10 < sup > 10 </ sup > times that of the Sun ).

Individual burst energetics are characterized by an integrated flux of 10 < sup > 39 – 40 </ sup > ergs, compared to the steady luminosity which is of the order 10 < sup > 37 </ sup > ergs for accretion onto a neutron star.

Super-Eddington accretion onto stellar-mass black holes is one possible model for ultraluminous X-ray sources ( ULXs ).

The disk eventually disappears due to accretion onto the central star, planet formation, ejection by jets and photoevaporation by UV-radiation from the central star and nearby stars.

The protoplanetary disk is sometimes referred to as an accretion disk, because while the young T Tauri-like protostar is still contracting, gaseous material may still be falling onto it, accreting on its surface from the disk's inner edge.

The protoplanetary disk may be considered an accretion disc because gaseous material may be falling from the inner edge of the disk onto the surface of the star, but this process should not be confused with the accretion process thought to build up the planets themselves.

Accretion of gas onto the star continues for another 10 million years, before the disk disappears, perhaps being blown away by the young star's solar wind, or perhaps simply ceasing to emit radiation after accretion has ended.

Sunyaev and Nikolay I. Shakura developed a model of accretion onto black holes, from a disk, and he has proposed a signature for X-radiation from matter spiraling into a black hole.

The current model associates the FU Orionis flare with abrupt mass transfer from an accretion disc onto a young, low mass T Tauri star.

Bondi also contributed to the theory of accretion of matter from a cloud of gas onto a star or a black hole, working with Raymond Lyttleton and giving his name to " Bondi accretion " and the " Bondi radius ".

The captured material forms a gaseous accretion disc and spirals inwards to ultimately fall onto the neutron star as in the binary system Cen X-3.

The oceanic crustal fragments may be obducted as ophiolites onto the continent during terrane accretion.

Stars are often surrounded by accretion disks in their first few hundred thousand years of existence, which form as gas falls onto them, and the rapid rotation of the inner parts of these disks leads to the emission of narrow jets of partially ionised plasma perpendicular to the disk, known as polar jets.

A dwarf galaxy remnant in Canis Major: the fossil of an in-plane accretion onto the Milky Way.

When the Taconic Orogeny subsided during Late Ordovician time ( about 440 million years ago ), subduction ended, culminating in the accretion of the Iapetus Terrane onto the eastern margin of the continent.