Wei Zhu（祝伟）
I'm now an Assistant Professor in the Department of Astronomy at Tsinghua University in Beijing.
Wei Zhu (祝伟)
Canadian Institute for Theoretical Astrophysics
\(\longrightarrow\) Tsinghua University (2021 March)
Exoplanet Demographics, 2020-11-11
http://astro.tsinghua.edu.cn/
Image credit: iLectureOnline
\(\Delta I = 5.7^\circ \quad \quad \quad 2.1^\circ \quad \quad \quad~~ 1.3^\circ \quad \quad \quad \quad 0.5^\circ ~~ \quad \quad \quad - \quad \quad \quad \quad 2.1^\circ \quad \quad \quad \quad 0.5^\circ \quad \quad \quad \quad 0.5^\circ \)
\(e = 0.21 \quad \quad \quad 0.01 \quad \quad 0.02 \quad \quad 0.06 ~~\quad \quad 0.05 \quad \quad \quad 0.06 \quad \quad 0.05 \quad \quad0.01 \)
w/ known companions
w/o known companions
Transit (ground)
Transit (space)
RV
Microlensing
Imaging
Based on data from NASA Exoplanet Archive.
\( \xi \equiv \frac{\rm (Transit~chord~length)_{in}}{\rm (Transit~chord~length)_{\rm out}} = \frac{T_{\rm in} P_{\rm in}^{-1/3}}{T_{\rm out} P_{\rm out}^{-1/3}} = \sqrt{\frac{1-b_{\rm in}^2}{1-b_{\rm out}^2}} \)
Figure from Ballard & Johnson (2016)
Transit doubles
Transit triples
Transit quadruples
\( \xi = \frac{T_{\rm in} P_{\rm in}^{-1/3}}{T_{\rm out} P_{\rm out}^{-1/3}} = \sqrt{\frac{1-b_{\rm in}^2}{1-b_{\rm out}^2}} \)
Transit singles
Transit doubles
Transit triples
Transit quadruples
Based on DR25 MCMC parameters and Berger et al. (2020) stellar parameters.
Zhu et al., 2018
(see also He et al. 2020)
\( \sigma_i,~\sigma_e \propto k^\zeta \)
Zhu et al., 2018
(see also He et al. 2020)
Orbital eccentricity
Coplanarity \(\longrightarrow\)>50% of Sun-like stars have Kepler-like planets (e.g., Fressin et al. 2013, Petigura et al. 2013).
mutual inclination
(Colors mean different multiplicities.)
Spacing in mutual Hill radii
See Zhu (2020) and Murchikova & Tremaine (2020).
Figure adapted from Penny et al. (2019)
Figure adapted from Penny et al. (2019)
Cold Jupiters
Super Earths
22 from Kepler (triangles) + 39 from RV (squares)
Zhu & Wu (2018), Bryan et al. (2019)
2 yr
Figure from Herman, Zhu & Wu (2019)
Pebbles (\(\sim\) cm)
Pebble isolation mass (\(\sim10\,M_\oplus\))
Figure adapted from Penny et al. (2019)
Figure from Zhu & Wu (2018)
(Kepler planets around Sun-like stars, based on Kepler DR25 & Gaia parameters)
0.4 \(R_\oplus\)
0.9 \(R_\oplus\)
1.0 \(R_\oplus\)
0.5 \(R_\oplus\)
11 \(R_\oplus\)
9 \(R_\oplus\)
4.0 \(R_\oplus\)
3.9 \(R_\oplus\)
See Zhu (2020) and Murchikova & Tremaine (2020).
By Wei Zhu（祝伟）
A review talk on multi-planet systems at the Exoplanet Demographics Conference.
I'm now an Assistant Professor in the Department of Astronomy at Tsinghua University in Beijing.