ALBERT

Description: We show that multiple machine learning algorithms can match human performance in classifying transient imaging data from the Sloan Digital Sky Survey (SDSS) supernova survey into real objects and artefacts. This is a first step in any transient science pipeline and is currently still done by humans, but future surveys such as the Large Synoptic Survey Telescope (LSST) will necessitate fully machine-enabled solutions. Using features trained from eigenimage analysis (principal component analysis, PCA) of single-epoch g , r and i difference images, we can reach a completeness (recall) of 96 per cent, while only incorrectly classifying at most 18 per cent of artefacts as real objects, corresponding to a precision (purity) of 84 per cent. In general, random forests performed best, followed by the k -nearest neighbour and the SkyNet artificial neural net algorithms, compared to other methods such as naive Bayes and kernel support vector machine. Our results show that PCA-based machine learning can match human success levels and can naturally be extended by including multiple epochs of data, transient colours and host galaxy information which should allow for significant further improvements, especially at low signal-to-noise.

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- New York, N.Y. -- Science. 1992 May 15;256(5059):1048-50.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17795019" target="_blank"〉PubMed〈/a〉

Description: Voyager 2 images of Neptune reveal a windy planet characterized by bright clouds of methane ice suspended in an exceptionally clear atmosphere above a lower deck of hydrogen sulfide or ammonia ices. Neptune's atmosphere is dominated by a large anticyclonic storm system that has been named the Great Dark Spot (GDS). About the same size as Earth in extent, the GDS bears both many similarities and some differences to the Great Red Spot of Jupiter. Neptune's zonal wind profile is remarkably similar to that of Uranus. Neptune has three major rings at radii of 42,000, 53,000, and 63,000 kilometers. The outer ring contains three higher density arc-like segments that were apparently responsible for most of the ground-based occultation events observed during the current decade. Like the rings of Uranus, the Neptune rings are composed of very dark material; unlike that of Uranus, the Neptune system is very dusty. Six new regular satellites were found, with dark surfaces and radii ranging from 200 to 25 kilometers. All lie inside the orbit of Triton and the inner four are located within the ring system. Triton is seen to be a differentiated body, with a radius of 1350 kilometers and a density of 2.1 grams per cubic centimeter; it exhibits clear evidence of early episodes of surface melting. A now rigid crust of what is probably water ice is overlain with a brilliant coating of nitrogen frost, slightly darkened and reddened with organic polymer material. Streaks of organic polymer suggest seasonal winds strong enough to move particles of micrometer size or larger, once they become airborne. At least two active plumes were seen, carrying dark material 8 kilometers above the surface before being transported downstream by high level winds. The plumes may be driven by solar heating and the subsequent violent vaporization of subsurface nitrogen.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- Soderblom, L A -- Banfield, D -- Barnet, C -- Basilevsky, A T -- Beebe, R F -- Bollinger, K -- Boyce, J M -- Brahic, A -- Briggs, G A -- Brown, R H -- Chyba, C -- Collins, S A -- Colvin, T -- Cook, A F 2nd -- Crisp, D -- Croft, S K -- Cruikshank, D -- Cuzzi, J N -- Danielson, G E -- Davies, M E -- De Jong, E -- Dones, L -- Godfrey, D -- Goguen, J -- Grenier, I -- Haemmerle, V R -- Hammel, H -- Hansen, C J -- Helfenstein, C P -- Howell, C -- Hunt, G E -- Ingersoll, A P -- Johnson, T V -- Kargel, J -- Kirk, R -- Kuehn, D I -- Limaye, S -- Masursky, H -- McEwen, A -- Morrison, D -- Owen, T -- Owen, W -- Pollack, J B -- Porco, C C -- Rages, K -- Rogers, P -- Rudy, D -- Sagan, C -- Schwartz, J -- Shoemaker, E M -- Showalter, M -- Sicardy, B -- Simonelli, D -- Spencer, J -- Sromovsky, L A -- Stoker, C -- Strom, R G -- Suomi, V E -- Synott, S P -- Terrile, R J -- Thomas, P -- Thompson, W R -- Verbiscer, A -- Veverka, J -- New York, N.Y. -- Science. 1989 Dec 15;246(4936):1422-49.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17755997" target="_blank"〉PubMed〈/a〉

Description: As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies. Saturn's atmosphere has numerous, low-contrast, discrete cloud features and a pattern of circulation significantly different from that of Jupiter. Titan is shrouded in a haze layer that varies in thickness and appearance. Among the icy satellites there is considerable variety in density, albedo, and surface morphology and substantial evidence for endogenic surface modification. Trends in density and crater characteristics are quite unlike those of the Galilean satellites. Small inner satellites, three of which were discovered in Voyager images, interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system. Saturn's broad A, B, and C rings contain hundreds of "ringlets," and in the densest portion of the B ring there are numerous nonaxisymmetric features. The narrow F ring has three components which, in at least one instance, are kinked and crisscrossed. Two rings are observed beyond the F ring, and material is seen between the C ring and the planet.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- Soderblom, L -- Beebe, R -- Boyce, J -- Briggs, G -- Bunker, A -- Collins, S A -- Hansen, C J -- Johnson, T V -- Mitchell, J L -- Terrile, R J -- Carr, M -- Cook, A F 2nd -- Cuzzi, J -- Pollack, J B -- Danielson, G E -- Ingersoll, A -- Davies, M E -- Hunt, G E -- Masursky, H -- Shoemaker, E -- Morrison, D -- Owen, T -- Sagan, C -- Veverka, J -- Strom, R -- Suomi, V E -- New York, N.Y. -- Science. 1981 Apr 10;212(4491):163-91.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17783827" target="_blank"〉PubMed〈/a〉

Description: Voyager 2 photography has complemented that of Voyager I in revealing many additional characteristics of Saturn and its satellites and rings. Saturn's atmosphere contains persistent oval cloud features reminiscent of features on Jupiter. Smaller irregular features track out a pattern of zonal winds that is symmetric about Saturn's equator and appears to extend to great depth. Winds are predominantly eastward and reach 500 meters per second at the equator. Titan has several haze layers with significantly varying optical properties and a northern polar "collar" that is dark at short wavelengths. Several satellites have been photographed at substantially improved resolution. Enceladus' surface ranges from old, densely cratered terrain to relatively young, uncratered plains crossed by grooves and faults. Tethys has a crater 400 kilometers in diameter whose floor has domed to match Tethys' surface curvature and a deep trench that extends at least 270 degrees around Tethys' circumference. Hyperion is cratered and irregular in shape. Iapetus' bright, trailing hemisphere includes several dark-floored craters, and Phoebe has a very low albedo and rotates in the direction opposite to that of its orbital revolution with a period of 9 hours. Within Saturn's rings, the "birth" of a spoke has been observed, and surprising azimuthal and time variability is found in the ringlet structure of the outer B ring. These observations lead to speculations about Saturn's internal structure and about the collisional and thermal history of the rings and satellites.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- Soderblom, L -- Batson, R -- Bridges, P -- Inge, J -- Masursky, H -- Shoemaker, E -- Beebe, R -- Boyce, J -- Briggs, G -- Bunker, A -- Collins, S A -- Hansen, C J -- Johnson, T V -- Mitchell, J L -- Terrile, R J -- Cook, A F 2nd -- Cuzzi, J -- Pollack, J B -- Danielson, G E -- Ingersoll, A P -- Davies, M E -- Hunt, G E -- Morrison, D -- Owen, T -- Sagan, C -- Veverka, J -- Strom, R -- Suomi, V E -- New York, N.Y. -- Science. 1982 Jan 29;215(4532):504-37.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17771273" target="_blank"〉PubMed〈/a〉

Description: A circumstellar disk has been observed optically around the fourth-magnitude star beta Pictoris. First detected in the infrared by the Infrared Astronomy Satellite last year, the disk is seen to extend to more than 400 astronomical units from the star, or more than twice the distance measured in the infrared by the Infrared Astronomy Satellite. The beta Pictoris disk is presented to Earth almost edgeon and is composed of solid particles in nearly coplanar orbits. The observed change in surface brightness with distance from the star implies that the mass density of the disk falls off with approximately the third power of the radius. Because the circumstellar material is in the form of a highly flattened disk rather than a spherical shell, it is presumed to be associated with planet formation. It seems likely that the system is relatively young and that planet formation either is occurring now around beta Pictoris or has recently been completed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- Terrile, R J -- New York, N.Y. -- Science. 1984 Dec 21;226(4681):1421-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17788996" target="_blank"〉PubMed〈/a〉

Description: A quadruple long exposure of Io in eclipse exhibits faint auroral emission from the eruptive plumes. No luminous spots in the vents, predicted by Gold, were observed. Heat from the interior of Io appears to be the predominant source of energy in the plumes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cook, A F -- Shoemaker, E M -- Smith, B A -- Danielson, G E -- Johnson, T V -- Synnott, S P -- New York, N.Y. -- Science. 1981 Mar 27;211(4489):1419-22.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17731183" target="_blank"〉PubMed〈/a〉

Description: Orbital parameter values and associated uncertainties determined from Voyager 1 imaging data for the satellites 1980S1, 1980S3, 1980S6, 1980S26, 1980S27, and 1980S28 are presented.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Synnott, S P -- Peters, C F -- Smith, B A -- Morabito, L A -- New York, N.Y. -- Science. 1981 Apr 10;212(4491):191-2.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17783828" target="_blank"〉PubMed〈/a〉

Description: The cameras aboard Voyager 1 have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- Soderblom, L A -- Johnson, T V -- Ingersoll, A P -- Collins, S A -- Shoemaker, E M -- Hunt, G E -- Masursky, H -- Carr, M H -- Davies, M E -- Cook, A F 2nd -- Boyce, J -- Danielson, G E -- Owen, T -- Sagan, C -- Beebe, R F -- Veverka, J -- Strom, R G -- McCauley, J F -- Morrison, D -- Briggs, G A -- Suomi, V E -- New York, N.Y. -- Science. 1979 Jun 1;204(4396):951-72.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17800430" target="_blank"〉PubMed〈/a〉

Description: Voyager 2, during its encounter with the Jupiter system, provided images that both complement and supplement in important ways the Voyager 1 images. While many changes have been observed in Jupiter's visual appearance, few, yet significant, changes have been detected in the principal atmospheric currents. Jupiter's ring system is strongly forward scattering at visual wavelengths and consists of a narrow annulus of highest particle density, within which is a broader region in which the density is lower. On Io, changes are observed in eruptive activity, plume structure, and surface albedo patterns. Europa's surface retains little or no record of intense meteorite bombardment, but does reveal a complex and, as yet, little-understood system of overlapping bright and dark linear features. Ganymede is found to have at least one unit of heavily cratered terrain on a surface that otherwise suggests widespread tectonism. Except for two large ringed basins, Callisto's entire surface is heavily cratered.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- Soderblom, L A -- Beebe, R -- Boyce, J -- Briggs, G -- Carr, M -- Collins, S A -- Cook, A F 2nd -- Danielson, G E -- Davies, M E -- Hunt, G E -- Ingersoll, A -- Johnson, T V -- Masursky, H -- McCauley, J -- Morrison, D -- Owen, T -- Sagan, C -- Shoemaker, E M -- Strom, R -- Suomi, V E -- Veverka, J -- New York, N.Y. -- Science. 1979 Nov 23;206(4421):927-50.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17733910" target="_blank"〉PubMed〈/a〉