JB Gayet

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JB Gayet last won the day on December 17 2018

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About JB Gayet

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    Collectionneur de pétouilles

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    Astro. Imagerie. Sciences. Collectionneur.
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    30 rue René Boulanger
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    Planewave CDK 12.5 Paramount II QHY600 M en remote
    Celestron C14 AP 1100 GTPO ZWO ASI 174 MM en local

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  1. La controverse NGC 4319 - Mrk 205

    Bon, j'ai regardé les sources que vous citez. Rien de bien évident. Par contre, j'ai trouvé un autre truc assez rigolo : Observations have revealed that high-redshift quasars may be associated with low-redshift galaxies (Arp 1971a; Stockton 1973; Lo´pez-Corredoira & Gutie´rrez 2004). For instance, the compact, high-redshift object Markarian 205 appears to lie within a spiral arm of the low-redshift galaxy NGC 4319 (Arp 1971b; Sulentic 1983). Arp (1987) suggested that quasars were ejected from their parent galaxies and the extra redshifts are due to the Doppler effect from extremely high speed ejections. This interpretation does not explain why we have never observed a blueshifted quasar or why perpendicular ejections also display large redshift differences between the quasars and the parent galaxies. In addition, the physics of such ejections has not yet been developed. If the associations between quasars and galaxies with different redshifts are real, a new redshift mechanism needs to be developed. In this Letter, such a mechanism is proposed in accord with the Kaluza-Klein (K-K) theory ... La suite est chaud patate à lire... et je saute directemement à sa conclusion : In summary, we have proposed a new redshift mechanism— the electric redshift—according to the five-dimensional fully covariant K-K theory with a scalar field. It has been shown that a dense, massive, and charged body can significantly shift a light ray that is emitted from or reflected by the body’s surface toward the red as compared with the Einsteinian gravitational redshift. This study suggests that quasars are compact stars, charged as a result of holding a certain amount of extra protons, with density and mass comparable to or even greater than those of a neutron star. Not only can the new redshift mechanism be used to explain the associations between quasars and galaxies with different redshifts, but it also does not conflict with big bang cosmology, because for normal stars, galaxies, and large-scale matter, the electric redshifts are negligible as a consequence of the relatively low densities and lack of electric charge. Source : Electric redshift and quasards. T. X. Zhang. The Astrophysical Journal, Volume 636, Issue 2, pp. L61-L64. Ca date un peu (2006) Si la beauté de sa démonstration est toute mathématique, et son travail assez remarquable, moi ce qui me laisse perplexe c'est tout de même le peu d'observations qui abonderait dans son sens.. Quoiqu'il en soit, le sujet divise (a divisé ?) la communauté. Moi je n'ai clairement pas le niveau :)) Et si voulez lire un papier de synthèse très bien fait résumant les différentes théories sur les redshifts, il y a ça : On the Interpretation of Spectral Red-Shift in Astrophysics: A Survey of Red-Shift Mechanisms - II. Louis Marmet (2018) J'aime beaucoup sa conclusion This paper was written to collect as many red-shift mechanisms as possible in a single, coherent presentation. Many questions arise: “Which one of these best describes the observations?” “Which one, if any, is right?” There are so many proposed mechanisms with even more adjustable parameters, it is possible that a few might fit experimental results within measurement errors. However, this doesn’t mean that the model is right. Another method might be required in the future to decide which, if any, of these provides a good explanation for the red-shift. During the great depression of the 1930’s, it was observed that men wearing gold watches were in better health than other people. The correlation between gold and the weight of these men was explained with some assumed property of gold. Although the theory explained the observations very well, it was certainly incorrect - richer men who could afford to buy gold had enough money to feed themselves. This anecdote is to be remembered when considering the above models and how well they fit experimental data. JB www.ciel-de-nuit.com
  2. La controverse NGC 4319 - Mrk 205

    Hello Christian Oui, tu as bien raison, li y a eu d'autres exemples depuis. L'auteur du papier que je linkais en citais déjà lui-même un en 2000 (NGC 4258) dans son abstract Mais sujet très intéressant c'est clair
  3. La controverse NGC 4319 - Mrk 205

    La controverse n'a pas beaucoup avancé, mais plus récemment que l'article cité par Christian, on peut surtout retenir l'hypothèse de l'effet Doppler relativiste. Probably, the most intriguing case of closely associated objects having discordand redshifts is represented by the galaxy NGC 4319 (z=0.006) and a peculiar object Mrk 205 (z=0.07) just 40'' away [1]. The luminous connection extending from Mrk 205 into the galaxian nucleus as well as a corresponding feature on the opposite side of the disk linking the nucleus with a bright UV knot may indicate an explosive ejection of both the objects from the nucleus [2]. Below, I propose to explain the essentially discordant redshifts of Mrk 205 and the UV knot by ejecting them with a relativistic velocity, similar to the two redshifted peculiar objects aligned across NGC 4258 [3]. In my interpretation, the redshift of Mrk 205 includes (i) a receding component, zr=0.065, due to the transverse Doppler effect and (ii) a cosmological component, zc=0.006. The velocity of ejection and the angle between the direction of ejection and the line of sight are found to be [etc., etc.]. If confirmed, this model would indicate that some pairs of quasar-like sources aligned with galaxies represent relativistic ejecta from the galactic nuclei, and the redshifts of those sources include a substantial component produced by the transverse Doppler effect. Ce que l'on peut traduire rapidement par : la galaxie NGC 4319 (z = 0,006) et l'objet particulier Mrk 205 (z = 0,07) à seulement 40 '' de distance forment probablement le cas le plus intrigant d'objets étroitement associés à discordance de redshift. La "connexion lumineuse" (sic) s'étendant de Mrk 205 dans le noyau galactique ainsi qu'à une structure correspondante au côté opposé du disque, reliant le noyau à une source UV brillante, pourrait indiquer une éjection explosive de deux objets du noyau." En gros, l'auteur propose d'expliquer les redshifts hautement discordants de Mrk 205 et de la source UV par une éjection à une vitesse relativiste. L'effet Doppler relatviste (Transversal Doppler Effet - TDE) est prédit par la relativité restreinte : https://fr.wikipedia.org/wiki/Effet_Doppler_relativiste Source : https://ui.adsabs.harvard.edu/abs/2000AAS...197.7503O/abstract Merci pour le déterrage de post, en fait
  4. NGC6946 - C11

    Un cliché assez typique de C11 Je me demande si je n'aurai pas essayer "d'éteindre" un peules étoiles par une réduction, tout de même
  5. Le trio du Dragon

    Excellente cible et aussi bien les couleurs que l'acquisition sont au top
  6. Bon ben y a plus qu'à s'incliner devant le diamètre hahaha
  7. Premiers essais Newton 510 mm en ciel profond

    Sacré setup !!! Whoohoo fait parler la poudre :))
  8. Ca rejoint l'APOD qui a été publié il y a qq jours bravo
  9. Très belle image en full, qui donne beaucoup de profondeur à cet amas assez harmonieux et très bons traitements
  10. NGC3628, Newton200/900, Moravian 4022

    plutôt réussie ! Reste à en empiler quelques unes pour en voir la queue de marée et ce sera tout bon :))
  11. Pohpohpoh il y en a tellement !!
  12. Nébuleuse de l'Iris

    Ca a l'air pas simple à traiter, c'est clair....
  13. M106 et son jet

    Excellente mise en abyme de ce jet !
  14. M51 avec le Newton 150-750 (15/04/2021)

    Pas mieux que les premiers commentaires... je me souviens de mon vieux 114/900 et de mes argentiques.... ça n'aurait pas donné le 10ème de ça :))
  15. L'APOD : bravo Sauveur !

    Ah mais il y a aussi @Jean-Baptiste_Paris le 27 dis donc !! Bravo les gars !!