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Никаких новостей нет?
KIC 8462852 опять начала загадочно тускнеть
Вот так умирают инопланетяне, вот так умирают мечты. Полная тишина и печаль в ответ на долгожданную новость. Где теперь все эти люди, светящиеся радостью и предвкушением от грядущей встречи? Нет их больше, умерли они все.
В середине октября 2015 года Табета Бойяджиан (Tabetha Boyajian) из Йельского университета и ее коллеги рассказали о необычных флуктуациях в яркости звезды KIC 8462852 в созвездии Лебедя, которые могут указывать на присутствие в ее окрестностях так называемой сферы Дайсона, созданной сверхразвитой цивилизацией инопланетян.
так как мы даже не знаем возможны ли вообще сферы Дайсона
Сейчас KIC 8462852 находится за Солнцем для наблюдателей на Земле,
Земля вокруг Солнца вообще-то вращается......
Ув. vsf покинул сей раздел ещё в прошлом году...
A Drop in Optical Flux from Boyajian's StarATel #10405; Tabetha Boyajian (Louisiana State), Steve Croft (UC Berkeley), Jason Wright (Penn State), Andrew Siemion (UC Berkeley), Matthew Muterspaugh (Tennessee State), Michael Siegel (Penn State), Bruce Gary (amateur), Shelley Wright (UCSD), Jerome Maire (UCSD), Andres Duenas (UCSD), Clayton Hultgren (UCSD), JonJohn Ramos (UCSD)on 20 May 2017; 00:29 UTCredential Certification: Steve Croft (scroft@astro.berkeley.edu)Subjects: Optical, Request for Observations, StarReferred to by ATel #: 10406Boyajian's Star (KIC 8462852) is an F3 dwarf that exhibits irregular and unexplained dips in optical brightness of up to tens of percent, as seen in Kepler observations (Boyajian et al. 2016). As part of an ongoing monitoring campaign, we obtained observations with a robotic 14-inch Celestron Telescope at Tennessee State University / Fairborn Observatory in Southern Arizona. Tentative evidence of small dips was seen beginning 2017 April 24, and enhanced monitoring at TSU/Fairborn (nightly photometry and spectra) commenced at that time. Cousins V-band images taken on UT 2017 May 18 and 19 showed that Boyajian's Star has entered into a new dip. Photometry differential to many comparison stars in the field showed a drop from an offset of Delta-V = 0.65144 +/- 0.00125 mag (UT 2017 May 16 09:16) to Delta-V = 0.67415 +/- 0.00261 (UT 2017 May 19 06:08) - a drop of 0.02 mag. This is the largest and first clear dip seen in over a year of monitoring, and shows no sign of having yet reached a minimum. V-band observations by amateur astronomer Bruce Gary using a Meade LX200 GPS 14" with an SBIG ST-10XME CCD confirmed that Boyajian's Star had dimmed from V = 11.906 +/- 0.004 to V = 11.9244 +/- 0.0033 between UT 2017 May 14 and UT 2017 May 19 (an abrupt drop of 1.7%). Swift/UVOT observations taken UT 2017 May 18 15:19 show a slight but not statistically significant drop in flux (from v = 11.93 +/- .012 to v = 11.94 +/- .030) since UT 2017 May 10. The ground-based absolute photometry is to be preferred over that from UVOT. r'-band observations with the 1-m telescope at the Las Cumbres Observatory (LCO) in Maui show a 2% dip over two days from UT 2017 May 17 to 2017 May 19. A number of explanations have been proposed for dimming events seen in Boyajian's Star observations (both slow fades of <1% per year, and abrupt and irregular short-term fades). Some explanations postulate the presence of large amounts of gas and dust in the system (which would be expected to have an IR signature, not seen in Spitzer observations of the star by Marengo et al. 2015). However, the Spitzer observations were not taken at the time of a dip; to constrain the models, optical and infrared spectroscopy and photometry are urgently needed. Dips typically last for a few days. Larger dips can last over a week. We will continue our monitoring observations using Swift, LCO, and Fairborn, as well as our spectroscopic observations as part of the Breakthrough Listen program using the APF-Levy spectrometer at Lick Observatory (27 epochs obtained since Nov 21, 2015). Near-InfraRed Optical SETI (NIROSETI) on the Nickel 1-m telescope at Lick Observatory has been monitoring Boyajian's Star, conducting 65 minutes of observations of the star UT 2017 May 20, and will continue to monitor the star UT 2017 May 21, 22, and 23. We encourage additional multi-wavelength follow-up. Especially interesting would be lines in the region between H-alpha and the sodium doublet, inclusive, and thermal infrared measurements.
Medium Resolution Spectroscopy of Boyajian's Star (KIC 8462852)ATel #10406; I. A. Steele, G. P. Lamb, C. M. Copperwheat, H. E. Jermak (Liverpool JMU)on 20 May 2017; 14:50 UTCredential Certification: Iain Steele (iainsteele@mac.com)Subjects: Optical, StarATel #10405 reports that a several percent dip in the brightness of KIC 8462852 is underway.We report medium resolution spectroscopy (R=2500) taken with the FRODOSpec fibre fed integral field spectrograph of the 2.0 meter Liverpool Telescope, La Palma obtained on 20th May 2017 starting at 01:20UT. Three 600 second exposures were obtained, giving a total integration time of 1800 seconds. The wavelength range was 5800 - 9400 Angstroms.The spectrum is compared with a reference spectrum obtained "out of dip" on 4th July 2016 with an identical instrumental setup and exposure time.In an initial analysis we find no difference between the two spectra apart from in features that are attributable to the expected variable telluric absorption features in the Earth's atmosphere.Excerpts of the spectra in the region of H-alpha (https://www.dropbox.com/s/u11lv7d5opeo0rr/KIC-halpha.png?dl=0) and the IR Calcium Triplet (https://www.dropbox.com/s/isev1ymggilx4hl/KIC-Ca.png?dl=0) are shown (the different ripples in the two Ca spectra are due to CCD fringing in the detector). Taking the ratio of the two spectra gives standard deviations per pixel of 2 percent of the continuum level in the H-alpha region and 3 percent in the Calcium triplet region, with no evidence of any changes visible between the two epochs in the lines.We will continue to monitor the object. We would like to thank Drs Klaas Wiersema (Leicester) and Grant Kennedy (Cambridge) for bringing the notification of the current dip to our attention.Liverpool Telescope
Back of the envelope: if period ~750d, circular orbit & events last 2.5d, transiting objects are ~5 times the radius of the Sun #TabbysStar
Надо-бы наложить новые затмения на на предмет кратности новых затмений 48,4 суткам. Если совпадёт - это будет бомба
Further, taking the six deepest dips (at Kepler days 261, 793, 1206, 1496, 1523, and 1568), one finds that they all fall within a narrow range of phases when folded at a period near 24.2 days, suggesting a close-in orbital period. Boyajian et al. 2016) paid particular attention to the possibility of a 48.4 days orbital period with events occurring at both primary and secondary eclipse.Indeed, a search of 2000 periods evenly sampled in frequency between 10 and 700 days reveals that M(P) is maximized with a value of 32.9 at P = 24.2 days. We then repeated this exercise for 10,000 mock sets of six dips with times randomly drawn from a uniform distribution with the same range as the Kepler time series. The corresponding set of 10,000 max(M) values has median 30.4, with 16.5% of all mock sets having a higher value (i.e. more significant clustering) than the actual Kepler dips. The median period P that maximized M in each of the 10,000 mock sets was 20.8 days.From this we conclude that the apparent periods found among the deepest dips are unlikely to be significant, though we acknowledge that more robust statistical treatments are likely available.
A potential constraint on the location of the cause of the dimming is periodicities in the patterns of dips in the Kepler light curve. Periods near 1 year might indicate obscurers in or near the solar system, with dimming modulated by the annual parallax. Other periods would presumably correspond with the orbital motion of material orbiting Boyajian’s Star.Indeed, the deepest points of the deepest dips (at Kepler days 793 and 1523) occur 2.000 years apart, a suspiciously precise interval. It should be noted, however, that Kepler is in an Earth-trailing orbit with an orbital period of 372.5 days. This means that the dips are separated by 1.96 Kepler years and that the dips’ separation’s coincidence with an Earth sidereal year is not important.
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То есть тут появляется объяснение, что затмевающие облака находятся где-то в Солнечной Системе (возможно, это пылевые облака от столкнувшихся оортоидов).
Автор
Тема: Попытки объяснения необычных затмений некоторых звёзд (Прочитано 167930 раз)
