A Turtorial Lecture on Exoplanets Wing-Huen Ip Institutes of Astronomy and Space Science National Central University August 31, 2012
Jan 01, 2016
A Turtorial Lecture on Exoplanets
Wing-Huen IpInstitutes of Astronomy and Space
ScienceNational Central University
August 31, 2012
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Planets before 1995…small rocky planets close to the Sun
gas-giant planets more distant from the star
Discovery of the first exoplanet: Peg 51b in 1995
http://spiff.rit.edu/classes/phys230/lectures/planets/planets.html
Red Shift Effect and Hubble Constant
http://www.answersingenesis.org/articles/tba/universe-confirms-bible
http://astronomy21st.blogspot.tw/2010/03/universe-expansion-is-speeding-up.html
The Hot Jupiters• Tidal interaction and/or electromagnetic effects
(Cuntz and Shkolnik, 2002)?• Superflares from star-planet interaction )Rubenstein
and Schaefer (2000)?
Star-planet Magnetic Interaction
Three Types of Magnetic Coupling
Ip, Kopp and Hu (2004)
Power = VB2L2 ergs/s~ 1027 ergs/s
Observational Test• Detection of excessive Ca II H and K line emission-
synchronized to orbital period of the Hot Jupiter ( Skholnik et al. 2005)
• On/off nature of such hot spots (Skholnik et al., 2008)
Kepler Observations
• Maehara et al. (2012): Superflares on solar-type stars• 9751 sola-type stars in Kepler field• 365 superflares (>1035 ergs) in 148 stars
Kepler Observations
• Maehara et al. (2012): Superflares on solar-type stars• 9751 sola-type stars in Kepler field• 365 superflares (>1035 ergs) in 148 stars • None of them has Hot Jupiter!
Kepler Observations• Maehara et al. (2012): Superflares on solar-type stars• 9751 sola-type stars in Kepler field• 365 superflares (>1035 ergs) in 148 stars • One million times stronger than the biggest solar flares ever obeserved.• Frequency is about once every 5000 years• None of them has Hot Jupiter!
Could Superflares happen on the Sun?
Search for Earth-like Habitable Exoplanets by the
Kepler Mission:New Results from IAU GA, Beijing
(20-31, 8, 2012)
The Kepler Mission• The scientific objective of Kepler is to explore the structure and
diversity of planetary systems.[45] This spacecraft observes a large sample of stars to achieve several key goals:
• To determine how many Earth-size and larger planets there are in or near the habitable zone (often called "Goldilocks planets")[46] of a wide variety of spectral types of stars.
• To determine the range of size and shape of the orbits of these planets.
• To estimate how many planets there are in multiple-star systems.• To determine the range of orbit size, brightness, size, mass and
density of short-period giant planets.• To identify additional members of each discovered planetary
system using other techniques.• Determine the properties of those stars that harbor planetary
systems.
Planetary candidates observed by Kepler III. Analysis of the first 16
months of data
• Batalha, N. et al.• arXiv:1202.5852, 2012
Kepler-20: A sun-like star with three-sub-Naptune exoplanets and two
Earth-size candidates
• Gautier, T.N., et al.• ApJ, 749, 15, 1, 2012
Kepler-20e and 20f
Kepler-20 (also designated as KOI 070, KIC 6850504 and 2MASS J19104752+4220194) is a G8V star of Kepler magnitude 12.497 and celestial coordinates right ascension α = 19 h 10 min 47.5 s and declination δ = +42° 20 19.38 . The stellar properties are listed in ′ ′′Table 1. The photometric data used for this work were gathered between 13 May 2009 and 14 March 2011 (quarter 1 to quarter 8), and comprise 29,595 measurements at a cadence of 29.426 min (black dots). The Kepler photometry phase-binned in 30-min intervals (blue dots with 1σ standard error of the mean (s.e.m.) error bars) for Kepler-20 e (a) and Kepler-20 f (b) is displayed as a function of time, with the data detrended4 and phase-folded at the period of the two transits. Transit models (red curves) smoothed to the 29.426-min cadence are overplotted. These two signals are unambiguously detected in each of the eight quarters of Kepler data, and have respective signal-to-noise ratios of 23.6 and 18.5, which cannot be due to stellar variability, data treatment or aliases from the other transit signals4.
Keplere-20e and 20fKepler-20 e and Kepler-20 f theoretical mass and observed radius ranges (1σ) are plotted as orange- and green-shaded areas, while the other transiting planets with dynamically determined masses are plotted in black, with 1σ error bars. The curves are theoretical constant-temperature mass–radius relations27. The solid lines are homogeneous compositions: water ice (solid blue), MgSiO3 perovskite (solid red), and iron (magenta). The non-solid lines are mass–radius relations for differentiated planets: 75% water ice, 22% silicate shell and 3% iron core (dashed blue); Ganymede-like with 45% water ice, 48.5% silicate shell and 6.5% iron core (dot-dashed blue); 25% water ice, 52.5% silicate shell and 22.5% iron core (dotted blue); approximately Earth-like with 67.5% silicate mantle and 32.5% iron core (dashed red); and Mercury-like with 30% silicate mantle and 70% iron core (dotted red). The dashed magenta curve corresponds to the density limit from a formation model24. The minimum density for Kepler-20 e corresponds to a 100% silicate composition, because this highly irradiated small planet could not keep a water reservoir. The minimum density for Kepler-20 f follows the 75% water-ice composition, representative of the maximum water content of comet-like mix of primordial material in our Solar System28.
Architecture and dynamics of Kepler’s candidate multiple transiting planet
system
• Lissauer, J., et al.• ApJ Suppl. Series, 197, 1, 2011
Kepler-47b and c: A planetary system orbiting around a binary star
(8/29/2012)NASA's Kepler Discovers Multiple Planets Orbiting a Pair of StarsPublished by Klaus Schmidt on Wed Aug 29, 2012 12:37 pm via: NASAShareMore share options
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MOFFETT FIELD, Calif. — NASA’s Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. The system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus. Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, this discovery proves that more than one planet can form and persist in the stressful realm of a binary star. The discovery demonstrates the diversity of planetary systems in our galaxy.
NASA Press Conference at IAU at Beijing on August 29, 2012 by Dr. Natalie Batalha
and Prof. William Welsh
Star War!
http://articles.businessinsider.com/2011-09-27/home/30207350_1_kepler-spacecraft-telescopes-european-southern-observatory