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Applegate originalment tenia la intenció d'escriure cada llibre d'Animorphs ella mateixa. No obstant això, a causa de molts factors que van contribuir –com el naixement del seu fill i les dificultats per escriure Everworld (que originalment es va concebre per ser un escriptor fantasma, com la tercera sèrie d'Scholastic d'Applegate Remnants), va acabar tenint un gran nombre de llibres escrits per escriptors fantasmes.

Joguines[modifica]

La línia de joguines Animorphs va ser introduïda el 1999 per Hasbro. Es van comercialitzar com a part de la sèrie Transformers, tot i que no hi havia connexió en l'univers entre les dues franquícies. No obstant això, les joguines Animorph no van tenir èxit comercialment i la línia de joguines va ser cancel·lada aviat. Després de la cancel·lació, diverses joguines previstes per formar part de la línia Animorphs van ser lleugerament remodelades i llançades com a part de la línia de mutants Beast Wars.

Adaptacions[modifica]

Sèries de televisió[modifica]

Una sèrie de televisió del mateix nom va funcionar des de setembre de 1998 fins a març de 2000 als Estats Units i al Canadà. Animorphs va comptar amb 26 episodis durant dues temporades, que es van emetre a YTV (primera temporada) i Global (segona temporada) a Canadà i Nickelodeon als Estats Units.

Pel·lícula[modifica]

Al setembre de 2015, diversos llocs web de pel·lícules van començar a informar rumors que Universal Pictures tenia previst adaptar la sèrie de llibres a una pel·lícula, basada en un informe de la pàgina web de la pel·lícula The Tracking Board.[1] El lloc web també va afirmar que Universal treballaria amb Silvertongue Films, una casa de producció llançada per desenvolupar els llibres Scholastic en llargmetratges, i que Deborah Forte produiria.[2][3]



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Estrelles de població I[modifica]

Population I, or metal-rich stars, are young stars with the highest metallicity out of all three populations. The Earth's Sun is an example of a metal-rich star. These are common in the spiral arms of the Milky Way galaxy.

Generally, the youngest stars, the extreme Population I, are found farther toward the center of a galaxy, and intermediate Population I stars are farther out. The Sun is considered an intermediate Population I star. Population I stars have regular elliptical orbits of the galactic centre, with a low relative velocity. It was hypothesised that the high metallicity of Population I stars makes them more likely to possess planetary systems than the other two populations, because planets, particularly terrestrial planets, are thought to be formed by the accretion of metals.[4] However, observations of the Kepler data-set have found smaller planets around stars with a range of metallicities, while only larger potential gas giant planets are concentrated around stars with relatively higher metallicity, a finding that has implications for theories of gas giant formation.[5]

Between the intermediate populations I and II comes the intermediary disc population.

Població I, o estrelles riques en metalls, són estrelles joves amb la més alta metal·licitat de les tres poblacions. El Sol de la Terra és un exemple d'una estrella rica en metalls. Aquests són comuns en els braços espirals de la galàxia de la Via Làctia.

En general, les estrelles més joves, l'extrema Les estrelles de població I, es troben més cap al centre d'una galàxia, i població intermèdia I estrelles estan més lluny. El Sol és considerat una estrella intermèdia de Població I. Les estrelles de població I tenen òrbites el·líptiques regulars del centre de la galàxia, amb una velocitat relativa baixa. Es va formular la hipòtesi que l'alta metal·licitat de les estrelles de població I fa més probable que posseeixen sistemes planetaris que les altres dues poblacions, perquè els planetes, en particular els planetes terrestres, es creu que està format per l'acumulació de metalls. [22] Tanmateix, les observacions de les dades de conjunt de Kepler han trobat planetes més petits al voltant d'estrelles amb una gamma de metal·licitat, mentre que només grans potencials planetes gegants de gas es concentren al voltant d'estrelles amb relativament més alta metal·licitat, una troballa que té implicacions per a les teories de formació gegant de gas. [23]

Entre les poblacions intermèdies I i II ve la població del disc intermediari.

Estrelles de població II[modifica]

Population II, or metal-poor stars, are those with relatively little metal. The idea of a relatively small amount must be kept in perspective as even metal-rich astronomical objects contain low percentages of any element other than hydrogen or helium; metals constitute only a tiny percentage of the overall chemical makeup of the universe, even 13.8 billion years after the Big Bang. However, metal-poor objects are even more primitive. These objects formed during an earlier time of the universe. Intermediate Population I stars are common in the bulge near the centre of our galaxy; whereas Population II stars found in the galactic halo are older and thus more metal-poor. Globular clusters also contain high numbers of Population II stars.[6] It is believed that Population II stars created all the other elements in the periodic table, except the more unstable ones. An interesting characteristic of Population II stars is that despite their lower overall metallicity, they often have a higher ratio of alpha elements (O, Si, Ne, etc.) relative to Fe as compared to Population I stars; current theory suggests this is the result of Type II supernovae being more important contributors to the interstellar medium at the time of their formation, whereas Type Ia supernovae metal enrichment came later in the universe's evolution.[7]

Els científics han apuntat aquestes estrelles més antigues de diversos estudis diferents, incloent l'HK l'estudi objectiu-prisma de Timothy C. Beers et al. i l'Hamburg - ESO. l'estudi de Norbert Christlieb i altres, va començar originalment per quàsars tènues]]. Fins ara, s'han descobert i estudiat en detall uns deu estrelles pobres en metalls mateixes (com ara l'estrella de Sneden, l'Estrella de Cayrel Scientists have targeted these oldest stars in several different surveys, including the HK objective-prism survey of Timothy C. Beers et al. and the Hamburg-ESO survey of Norbert Christlieb et al., originally started for faint quasars. Thus far, they have uncovered and studied in detail about ten very metal-poor stars (such as Sneden's Star, Cayrel's Star, BD +17° 3248) and three of the oldest stars known to date: HE0107-5240, HE1327-2326 and HE 1523-0901. Caffau's star was identified as the most metal-poor star yet when it was found in 2012 using Sloan Digital Sky Survey data. However, in February 2014 the discovery of an even lower metallicity star was announced, SMSS J031300.36-670839.3 located with the aid of SkyMapper astronomical survey data. Less extreme in their metal deficiency, but nearer and brighter and hence longer known, are HD 122563 (a red giant) and HD 140283 (a subgiant).

Estrelles de població III[modifica]

Possible glow of Population III stars imaged by NASA's Spitzer Space Telescope.
Credit: NASA / JPL-Caltech / A. Kashlinsky (GSFC)

Population III, or extremely metal-poor stars (EMP),[8] are a hypothetical population of extremely massive and hot stars with virtually no metals, except possibly for intermixing ejecta from other nearby Pop III supernovae. Their existence is inferred from cosmology, but they have not yet been observed directly. Indirect evidence for their existence has been found in a gravitationally lensed galaxy in a very distant part of the universe.[9] They are also thought to be components of faint blue galaxies. Their existence is proposed to account for the fact that heavy elements, which could not have been created in the Big Bang, are observed in quasar emission spectra, as well as the existence of faint blue galaxies.[10] It is believed that these stars triggered a period of reionization. The recently discovered galaxy UDFy-38135539 is believed to have been a part of this process. Some theories hold that there were two generations of Population III stars.[11]

Artist's impression of the first stars, 400 million years after the Big Bang.

Current theory is divided on whether the first stars were very massive or not - theories proposed in 2009 and 2011 suggest the first star groups might have consisted of a massive star surrounded by several smaller stars.[12][13] One theory, which seems to be borne out by computer models of star formation, is that with no heavy elements and a much warmer interstellar medium from the Big Bang, it was easy to form stars with much greater total mass than the ones visible today.[cal citació] Typical masses for Population III stars would be expected to be about several hundred solar masses, which is much larger than that of current stars. Analysis of data on extremely low-metallicity Population II stars such as HE0107-5240, which are thought to contain the metals produced by Population III stars, suggest that these metal-free stars had masses of 20 to 130 solar masses instead.[14] On the other hand, analysis of globular clusters associated with elliptical galaxies suggests pair-instability supernovae, which are typically associated with very massive stars, were responsible for their metallic composition.[15] This also explains why there have been no low-mass stars with zero metallicity observed, although models have been constructed for smaller Population III stars.[16] Clusters containing zero-metallicity red dwarfs or brown dwarfs (possibly created by pair-instability supernovae[17]) have been proposed as dark matter candidates,[18][19] but searches for these and other MACHOs through gravitational microlensing have produced negative results.

Detection of Population III stars is a goal of NASA's James Webb Space Telescope.[20] New spectroscopic surveys, such as SEGUE or SDSS-II, may also locate Population III stars. [cal citació]

In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.[21][22]

  1. «The Animorphs Are Getting Their Own Movie Because Nostalgia», 11-09-2015.
  2. «‘Animorphs’ Film Updates: Universal Pictures to reboot classic 1990s best-selling book series? Film to rival Sony Pictures’ ‘Goosebumps’ adaptation», 14-09-2015.
  3. «{TB EXCLUSIVE} Universal Is Developing An “Animorphs” Movie Based On The Bestselling Book Series» (en en-us), 09-09-2015.
  4. Charles H. Lineweaver «An Estimate of the Age Distribution of Terrestrial Planets in the Universe: Quantifying Metallicity as a Selection Effect». Icarus, vol. 151, 2, 2000, pàg. 307–313. arXiv: astro-ph/0012399. Bibcode: 2001Icar..151..307L. DOI: 10.1006/icar.2001.6607.
  5. Buchhave, L.A. et al. (2012) An abundance of small exoplanets around stars with a wide range of metallicities. Nature 486:375–377
  6. T. S. van Albada «On the Two Oosterhoff Groups of Globular Clusters». Astrophysical Journal, vol. 185, 1973, pàg. 477–498. Bibcode: 1973ApJ...185..477V. DOI: 10.1086/152434.
  7. Wolfe, Gawiser, Prochaska, "DAMPED Lyalpha SYSTEMS", Annu. Rev. Astron. Astrophys. 2005. 43: 861–918 http://ned.ipac.caltech.edu/level5/Sept05/Wolfe/Wolfe3.html
  8. N. Tominga «Supernova Nucleosynthesis in Population III 13-50 Msolar Stars and Abundance Patterns of Extremely Metal-poor Stars». Astrophysical Journal, vol. 660, 5, 2007, pàg. 516–540. arXiv: astro-ph/0701381. Bibcode: 2007ApJ...660..516T. DOI: 10.1086/513063.
  9. R. A. E. Fosbury «Massive Star Formation in a Gravitationally Lensed H II Galaxy at z = 3.357». Astrophysical Journal, vol. 596, 1, 2003, pàg. 797–809. arXiv: astro-ph/0307162. Bibcode: 2003ApJ...596..797F. DOI: 10.1086/378228.
  10. Error de citació: Etiqueta <ref> no vàlida; no s'ha proporcionat text per les refs amb l'etiqueta Heger, A.; Woosley, S. E.
  11. V. Bromm «The formation of the first stars and galaxies». Nature, vol. 459, 7243, 2009. arXiv: 0905.0929v1. Bibcode: 2009Natur.459...49B. DOI: 10.1038/nature07990.
  12. Nola Redd. «The Universe's First Stars Weren't Loners After All». Space.com, February 2011. [Consulta: February 2015].
  13. Andrea Thompson. «How Massive Stars Form: Simple Solution Found». Space.com, January 2009. [Consulta: February 2015].
  14. Umeda, Hideyuki; Nomoto, Ken'Ichi «First-generation black-hole-forming supernovae and the metal abundance pattern of a very iron-poor star». Nature, vol. 422, 6934, 2003, pàg. 871–873. arXiv: astro-ph/0301315. Bibcode: 2003Natur.422..871U. DOI: 10.1038/nature01571. PMID: 12712199.
  15. Puzia, Thomas H.; Kissler‐Patig, Markus; Goudfrooij, Paul «Extremely α‐Enriched Globular Clusters in Early‐Type Galaxies: A Step toward the Dawn of Stellar Populations?». The Astrophysical Journal, vol. 648, 2006, pàg. 383–388. arXiv: astro-ph/0605210. Bibcode: 2006ApJ...648..383P. DOI: 10.1086/505679.
  16. Siess, Lionel; Livio, Mario; Lattanzio, John «Structure, Evolution, and Nucleosynthesis of Primordial Stars». The Astrophysical Journal, vol. 570, 2002, pàg. 329–343. arXiv: astro-ph/0201284. Bibcode: 2002ApJ...570..329S. DOI: 10.1086/339733.
  17. Error de citació: Etiqueta <ref> no vàlida; no s'ha proporcionat text per les refs amb l'etiqueta Salvaterra, R.; Ferrara, A.; Schneider, R.
  18. «Zero-metallicity very low mass stars as halo dark matter». Astronomy and Astrophysics, vol. 322, 1997, pàg. 709. arXiv: astro-ph/9610070. Bibcode: 1997A&A...322..709K.
  19. «On the Stringent Constraint on Massive Dark Clusters in the Galactic Halo». Astrophysical Journal Letters v.487, vol. 487, 1997, pàg. L61. Bibcode: 1997ApJ...487L..61S. DOI: 10.1086/310873.
  20. C-E. Rydberg «Detection of isolated Population III stars with the James Webb Space Telescope». MNRAS, vol. 429, 4, March 2013. arXiv: 1206.0007v2. Bibcode: 2013MNRAS.429.3658R. DOI: 10.1093/mnras/sts653.
  21. Sobral, David; Matthee, Jorryt; Darvish, Behnam; Schaerer, Daniel «Evidence For POPIII-Like Stellar Populations In The Most Luminous LYMAN-α Emitters At The Epoch Of Re-Ionisation: Spectroscopic Confirmation» (PDF). The Astrophysical Journal, 04-06-2015 [Consulta: 17 juny 2015].
  22. Overbye, Dennis «Astronomers Report Finding Earliest Stars That Enriched Cosmos». New York Times, 17-06-2015 [Consulta: 17 juny 2015].