KIC 8462852 Observations |
KIC 8462852 Observations |
Oct 15 2015, 04:45 PM
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
Kepler found one very, very strange case:
http://www.theatlantic.com/science/archive...-galaxy/410023/ In a nutshell, while Kepler was observing it, the star (larger and brighter than the Sun) exhibited four dimming events that took place at irregular intervals, blocked a lot more light than a Jupiter-sized planet would block, and had a "shape" that varied in all four cases and did not resemble a planet. This case is attracting some wild speculation… in fact, it is seemingly certain that something wild must be going on; it's just a matter of which wild scenario is the correct one. If I had to throw my hat in the ring, I'd guess that a distant collision and breakup has placed big swarms of matter into a very long-period orbit. But there's no hypothesis that's been offered that doesn't seem problematic. |
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Jan 16 2016, 06:04 PM
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
I noticed this statement from the Bradley E. Schaefer paper:
QUOTE The long-term trend in the DASCH light curve can be described in various ways. One way is simply to note that KIC8462852 faded from B=12.2650.028 in 1892.5 to B=12.4580.012 in 1987.5, for a total fading of 0.1930.030 mag in 95 years. This fade rate is +0.2030.032 magnitudes per century (dashed line in Figure 1). This end-to-end trend line provides an excellent representation of all the Harvard data except for the decade from 1900-1909. The individual plates for this decade show a similar distribution of magnitudes as in adjacent decades, except that there are many more fainter magnitudes (from 12.6-13.0). This might be due to the star suffering many deep dips during the years 1900-1909. This sounds plausible to me. It would mean that there has been a quite steady decline in brightness over the periods covered by the plates (1890-1953 and 1969-1989) at a rate of about 0.203 magnitude per century. But during the time period 1900-1909, many of the observations showed lower than expected brightnesses, perhaps due to there being a lot more "dips" than in the other years. Many (most?) of the observations in those years were still in line with the 1890-1989 trend, though. The author also stated that lower than expected brightnesses also occasionally happen at other times, so I assume that the observed rate of "dips" in the Kepler observations (2009-2013) would be consistent with the star's 1890-1900, 1910-1953 and 1969-1989 behavior. In this podcast Schaefer states that the only other comparable collection of plates to the Harvard Observatory collection that he had used, is the one created by the Sonneberg Observatory in Germany from the 1930s to the 1990s. This could be used to check the results found from the Harvard plate collection. |
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