protoplanetary disk

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protoplanetary disk

[‚prōd·ō‚plan·ä‚ter·ē ′disk]
(astronomy)
References in periodicals archive ?
The speaker remarked that the more distant of the two jets appeared anomalously faint and explained that this seemed to provide evidence for the presence of a proto-planetary disc, or proplyd, of solid material around the star, absorbing the X-rays from the jet behind it.
Earlier observations with the Hubble Space Telescope revealed striking images of proplyds in Orion.
The four images seen at right are of newly discovered proplyds buried deep inside the Carina Nebula.
Moreover, Carina is the older of the two nebulae, meaning most of the proplyds should have disappeared by now.
Until Smith and others obtain higher-resolution images of the Carina proplyds, including spectroscopy showing their mass-loss rates and ages, the paradox remains.
Jeff Hester and a team of colleagues used HST to take a detailed look at proplyds and jets in the well-known Trifid Nebula (), which lies about 9,000 light-years away in the constellation Sagittarius.
Proplyds all have discernible stars within them, while the contents of the somewhat larger EGGs are less clear.
Early evidence that proplyds exist in Orion includes some narrow-band images of the Trapezium from 1979 that show six unresolved stars with only emission lines.
The true nature of proplyds became clear after Hubble first observed this region in August 1991, and follow-up observations were made immediately after the telescope's refurbishment in December 1993.