In order to determine whether the surface of an extrasolar planet would contain water, scientists can look at what is called the protoplanetary disk - a disk of gas and dust surrounding a star during its early stages of development. ❋ Unknown (2010)
For those of you scoring at home, "planetesimals" were the first solid objects in our newly minted solar system (also known as the protoplanetary disk). ❋ Unknown (2009)
Now researchers have probed whether or not the necessary precursor to planet formation - a so-called "protoplanetary" disk of planet building blocks - could survive in this environment. ❋ Unknown (2010)
There are two proposed mechanisms for the formation of gas giants: (a) formation of a rocky/icy core through collisions of dust particles and a subsequent accretion of a gaseous envelope; (b) gravitational instability of the protoplanetary disk. ❋ Unknown (2010)
Neither the initial formation of the Sun from a molecular gas cloud, nor the subsequent formation of the planets from the protoplanetary disk was a violent process from the relativistic standpoint: the spacetime remained Newtonian. ❋ Unknown (2009)
"We need to see through gas and dust to see star formation and protoplanetary disks" – here's Spitzer. ❋ Unknown (2010)
Besides PSR B1257+12, at least one other pulsar planet is known PSR B1620+26 and a protoplanetary disk was revealed around the magnetar 4U 0142+61. ❋ Unknown (2010)
Smaller dust grains within the disk capture some of the UV radiation in the early formation periods of a protoplanetary disk. ❋ Unknown (2010)
AFAIU bodies in the protoplanetary disk accrete by collisions. ❋ Unknown (2010)
Larger organic molecules that coalesced in the dusty disk out of which our planets formed billions of years ago would have been broken apart by the Sun's rays, but calculations by two astronomers at the University of Michigan show that thousands of oceans worth of water present in a protoplanetary disk can shield other molecules from being broken up. ❋ Unknown (2010)
Looking deep inside the Orion Nebula, the Hubble Space Telescope has captured a stunning collection of protoplanetary disks – or proplyds – which are embryonic solar systems in the making. ❋ Unknown (2009)
Using Hubble's Advanced Camera for Surveys ACS, researchers have discovered 42 protoplanetary blobs, which are being illuminated by a bright star cluster. ❋ Unknown (2009)
A two-year look at "proplyds," or protoplanetary disks in the constellation Orion has provided astronomers with a new high-resolution time-lapse movie that reveals the process of how massive star form. ❋ Unknown (2009)
The catalog may be a boon to extrasolar planet hunters, as the protoplanetary disks from which these planets form will be another object visible to the instrument. ❋ Unknown (2009)
In itself, this is very exciting because nearly half of T Tauri stars have circumstellar disks or protoplanetary discs. ❋ Unknown (2009)
That is, they're launching the Wide-field Infrared Survey Explorer, a new infrared space telescope that will survey objects in our Solar System and beyond, looking for asteroids and brown dwarfs close to home, and protoplanetary disks and newborn stars far off. ❋ Unknown (2009)
I add the following passage and source link to Crumb's and Nereid2's research: "Space plasma researchers and pulse power engineers have long speculated that the progenitor of intense auroras, protoplanetary and planetary nebula, and supernovae is the Z- pinch, as both display the temporal, morphological, and radiation properties that are found in high-energy density plasma produced in laboratory and extreme high current explosive test experiments." ❋ Unknown (2009)
More recently the Hubble Space Telescope has imaged clearly a stellar nursery called the Orion Nebula and discovered that about 50% of the stars have disks of gas around them that could be solar systems in the making [Figure 7: Hubble Telescope images of protoplanetary nebulae]. ❋ Unknown (1995)
