Friday, March 3, 2023

Tabby Star

Even extended contortions are not getting us home here. We now have a century of explanations for astro explanations all suffering for any other data point that it not head on. Now imagine looking through a telescope and snapping an image of the top of my head. Make it slightly blurry.

Do you really think that any interpretation is trustworthy?  I sure do not.  Yet that is the nature of astronomy.  At least we have gotten wonderful at improving resolution and we are discovering all sorts of exoplanets which neatly cleaned up some of our more stretched prognostocations.  They all have planets of some sorty and we still do not know just how our solar system is so special.  It is by the way.

What is disappearing is the likelihood of  real earth like planets that are not like Mars, Venus and all those planet sized moons we do have.  Earth may turn out to be eceptional and Rare.

I will go much further than all that.  Earth is manufactured and we may even get to do the same to Venus.  Life throughout the Galaxy actually resides inside what are hollow planets of the correct size where it is very safe. Presume this is the case for all prospective planets in our solar system.  You are welcome to dismiss this assertion as I do not want to believe it either.  It is merely what scant evidence suggests.

Natural Explanations Are Being Eliminated for Tabby Star

February 27, 2023 by Brian Wang

Science Fiction author, John Michael Godier, has maintained close observation of the readings from observation of KIC8462852. The observations in the infrared is not agreeing with natural reasons like dust and asteroid breakups. The dust and asteroids need to have constant replenishment every few weeks. Any mechanism needs to keep repeating, so this eliminates singular random events. The infrared is not showing what we would expect from solar dust.

Tabby’s Star (also known as Boyajian’s Star and WTF Star, and designated KIC 8462852 in the Kepler Input Catalog) is an F-type main-sequence star in the constellation Cygnus approximately 1,470 light-years (450 parsecs) from Earth. Unusual light fluctuations of the star, including up to a 22% dimming in brightness, were discovered by citizen scientists as part of the Planet Hunters project. In September 2015, astronomers and citizen scientists associated with the project posted a preprint of an article describing the data and possible interpretations. The discovery was made from data collected by the Kepler space telescope, which observed changes in the brightness of distant stars to detect exoplanets.

The latest results have ruled out explanations involving only opaque objects such as stars, planets, swarms of asteroids, or more simple non-dynamic alien megastructures. There are other stars with some unusual dimming but not as unusual as Tabby’s Star. The cluster of stars with some dimming is near Tabby’s star and those stars are all Class-F or Class-G. 21 stars have dimming light curves. The seemingly normal F dwarf, KIC 8462852 (a.k.a. Boyajian’s Star), has been observed to exhibit two types of behavior unique among known variable stars: infrequent episodes of small brightness dips and a long-term decline in brightness between the dips. No satisfactory mechanism has been found for this behavior, at least in part, because there is only one known example. To begin to rectify this, we have searched for other stars exhibiting similar dipping behavior using the Northern Sky Variability Survey and have used data from the All Sky Automated Survey for Supernovae to further investigate the behavior. Twenty-one stars are identified as possible dippers. Fifteen may be similar to Boyajian’s star and the other six are likely to be more extreme examples of the same phenomenon. Using data from the Gaia Second Data Release we show that the dipper candidates are located in two restricted regions of the H-R diagram, near the main sequence with masses near 1 solar mass and in the red giant region near the evolutionary track for 2 solar mass stars. Stars in the former group are considered to be likely analogs to Boyajian’s star and should be studied in more detail to gain insights into the dipping phenomenon.

Observations of the luminosity of Tabby star by the Kepler space telescope showed small, frequent, non-periodic dips in brightness, along with two large recorded dips in brightness two years apart. The amplitude of the changes in the star’s brightness, and the aperiodicity of the changes, mean that this star is of particular interest for astronomers. The star’s changes in brightness are consistent with many small masses orbiting the star in “tight formation”.

NOTE: If Jupiter passed in front of our sun, this would cause a 0.5% dimming. The dimiming events are 15-40 times bigger.

The first major dip, on 5 March 2011, reduced the star’s brightness by up to 15%, and the next 726 days later (on 28 February 2013) by up to 22%. (A third dimming, around 8%, occurred 48 days later.) In comparison, a planet the size of Jupiter would only obscure a star of this size by 1%, indicating that whatever is blocking light during the star’s major dips is not a planet, but rather something covering up to half the width of the star. Due to the failure of two of Kepler’s reaction wheels, the star’s predicted 750-day dip around February 2015 was not recorded. The light dips do not exhibit an obvious pattern.

In addition to the day-long dimmings, a study of a century’s worth of photographic plates suggests that the star has gradually faded in 100 years (from c. 1890 to c. 1990) by about 20%, which would be unprecedented for any F-type main-sequence star. Teasing accurate magnitudes from long-term photographic archives is a complex procedure, however, requiring adjustment for equipment changes, and is strongly dependent on the choice of comparison stars. Another study, examining the same photographic plates, concluded that the possible century-long dimming was likely a data artifact, and not a real astrophysical event.[43] Another study from plates between 1895 and 1995 found strong evidence that the star has not dimmed, but kept a constant flux within a few percent, except an 8% dip on 24 October 1978, resulting in a period of the putative occulter of 738 days.

A third study, using light measurements by the Kepler observatory over a four-year period, determined that Tabby’s Star dimmed at about 0.34% per year before dimming more rapidly by about 2.5% in 200 days. It then returned to its previous slow fade rate. The same technique was used to study 193 stars in its vicinity and 355 stars similar in size and composition to Tabby’s Star. None of these stars exhibited such dimming.

In 2018, a possible 1,574-day (4.31-year) periodicity in dimming of the star was reported

KIC8462852 is a completely-ordinary F3 main sequence star, except that the light curve from Kepler shows episodes of unique and inexplicable day-long dips with up to 20% dimming. Here, I provide a light curve of 1338 Johnson B-band magnitudes from 1890 to 1989 taken from archival photographic plates at Harvard. KIC8462852 displays a secular dimming at an average rate of 0.164±0.013 magnitudes per century. From the early-1890s to the late-1980s, KIC8462852 faded by 0.193±0.030 mag. The decline is not an artifact because nearby check stars have closely flat light curves. This century-long dimming is unprecedented for any F-type main sequence star. Thus the Harvard light curve provides the first confirmation (past the several dips seen in the Kepler light curve alone) that KIC8462852 has anything unusual. The century-long dimming and the day-long dips are both just extreme ends of a spectrum of timescales for unique dimming events. By Ockham’s Razor, two such unique and similar effects are very likely produced by one physical mechanism. This one mechanism does not appear as any isolated catastrophic event in the last century, but rather must be some ongoing process with continuous effects. Within the context of dust-occultation models, the century-long dimming trend requires 104-107 times as much dust as for the deepest Kepler dip. Within the context of the comet-family idea, the century-long dimming trend requires an estimated 648,000 giant comets (each with 200 km diameter) all orchestrated to pass in front of the star within the last century.

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