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Rossby waves on the Sun as revealed by solar `hills'
Kuhn, J. R.; Bush, R. I.; Scherrer, P. +1 more
It is a long-standing puzzle that the Sun's photosphere-its visible surface-rotates differentially, with the equatorial regions rotating faster than the poles. It has been suggested that waves analogous to terrestrial Rossby waves, and known as r-mode oscillations, could explain the Sun's differential rotation: Rossby waves are seen in the oceans …
Interception of comet Hyakutake's ion tail at a distance of 500 million kilometres
Balsiger, H.; Geiss, J.; Schwadron, N. A. +6 more
Remote sensing observations and the direct sampling of material from a few comets have established the characteristic composition of cometary gas. This gas is ionized by solar ultraviolet radiation and the solar wind to form `pick-up' ions, ions in a low ionization state that retain the same compositional signatures as the original gas. The pick-u…
Identification of comet Hyakutake's extremely long ion tail from magnetic field signatures
Balogh, André; Jones, Geraint H.; Horbury, Timothy S.
Observations of the varying orientations of comet tails led to the suggestion of the existence of the solar wind-a continuous outflow of ionized material from the Sun. It is now well established that gas from comets is ionized by several processes and joins the solar wind, forming an ion (plasma) tail that points away from the Sun. The plasma envi…
Evidence against a redshift z > 6 for the galaxy STIS123627+621755
Dey, Arjun; Stanford, S. A.; Spinrad, Hyron +5 more
The identification of galaxies at extreme distances provides the most direct information about the earliest phases of galaxy formation. But at redshifts z > 5 even the most luminous galaxies appear faint; the interpretation of low signal-to-noise ratio data is difficult and misidentifications do occur. Here we report optical and near-infrared o…
Discovery of a comet by its Lyman-α emission
Bertaux, Jean-Loup; Laakso, Harri; Lallement, Rosine +6 more
Several searches for near-Earth objects have recently been initiated, as a result of increased awareness of the hazard of impacts on the Earth. These programs mainly search for asteroids, so amateur astronomers can still contribute to the discovery of comets, especially out of the orbital plane of the Solar System. An ideal way to search for comet…
Unusual spectral energy distribution of a galaxy previously reported to be at redshift 6.68
Chen, Hsiao-Wen; Lanzetta, Kenneth M.; Pascarelle, Sebastian +1 more
Observations of distant galaxies are important both for understanding how galaxies form and for probing the physical conditions of the Universe at early times. It is, however, very difficult to identify galaxies at redshifts <italic>z</italic> > 5, because they are so faint and have few spectral characteristics. We previously report…