Wei Zhu(祝伟)
I'm now an Assistant Professor in the Department of Astronomy at Tsinghua University in Beijing.
Wei Zhu (祝伟)
SURP Lecture
2019 June 12th
Image from Maruyama & Ebisuzaki (2017)
Snow line
Minimum-mass solar/extra-solar nebula:
Weidenschilling (1977); Hayashi (1981)
The outer region dominates the mass and angular momentum budget
Mimimum mass extra-solar nebula
Mimimum mass solar nebula
Chiang & Laughlin (2013)
Murcury
Mars
Asteroid
belt
Image credit: P. Armitage
Image credit: M. Rex
Image credit: Raymond, Izidoro, & Morbidelli (2018)
small planets alone
w/ outer Giants
'Pale Blue Dot' by Voyager 1 from 40 AU
Solar system seen from alpha centauri (1.3 pc)
Earth: R_Earth, 300 K
100xR_Earth, 6000 K
10xR_Earth, 150 K
(In addition, planets are very close to the star.)
HR 8799: planet brightness ~\(10^{-5}\) star
So far, <10 detections
First detection: 1989/1995
# of detections: ~700
First detection: 2000
# of detections: >4000
# of detections: 0
(Gaia ~2021)
First detection: 2003
# of detections: ~50
Ground-based transit
Radial velocity survey
Global microlensing survey
Kepler
Mayor & Queloz (1995)
Charbonneau et al. (2000)
Gillon et al. (2017)
Bond et al. (2003)
Hot Jupiters
Cold Jupiters
Cold Neptunes
Super Earths
Data from NASA Exoplanet Archive
Warm Jupiters
Sub-Saturns
RV
Transit
Microlensing
Figure from Bouchy et al. (2009)
Minimum-mass solar/extra-solar nebula:
Weidenschilling (1977); Hayashi (1981)
Mimimum mass extra-solar nebula
Mimimum mass solar nebula
Chiang & Laughlin (2013)
Murcury
Mars
Asteroid
belt
Figure from Dawson & Johnson (2018)
Dynamical channel
Disk migration
\(10^5\) target stars & 4-yr observations, how many Earth-like planets do we expect to detect?
0 Earth-like planets, but 1000s of exoplanets!
Saturn
Neptune
Earth
Hot Jupiters
Sub-Earths
Brightness
Brightness
Brightness
Einstein note, ~1912
Einstein (1936)
Planet 2
Planet 1
Sabrina Madsen
A pair of planets likely in mean-motion resonance from gravitational microlensing
Madsen & Zhu, ApJL in press
Light curve from Han et al. (2013)
Ground-based transit
Radial velocity survey
Global microlensing survey
Kepler
Mayor & Queloz (1995)
Charbonneau et al. (2000)
Gillon et al. (2017)
Bond et al. (2003)
Hot Jupiters
Cold Jupiters
Cold Neptunes
Super Earths
Data from NASA Exoplanet Archive
(1%)
(10%)
(30%)
(tens of %)
Warm Jupiters
(~3%)
Sub-Saturns
(~5%)
Neutron Star Planets
Binaries
Hot Jupiters
Cold Jupiters
Cold Neptunes
Super Earths
(1%)
(10%)
(30%)
(tens of %)
Warm Jupiters
(~3%)
Sub-Saturns
(~5%)
James Webb Space Telescope (~2021)
Star shade concept
RV also measures the orbital eccentricity and orientation
e=0
e=0.3
e=0.6
e=0.9
to observer
\( \omega \)
Figure from Dawson & Johnson (2018)
Solar system giant planets: \(e<0.06\)
Extra-solar giant planets: \(e\sim0.3\)
Major image perturbation
Minor image perturbation
By Wei Zhu(祝伟)
Lecture given to the 2019 UofT SURP students
I'm now an Assistant Professor in the Department of Astronomy at Tsinghua University in Beijing.