MAROON-X: An instrument for
identifying another Earth
David Charbonneau (Harvard)
Jacob Bean (U. Chicago)
Summary
Concept:
A radial velocity machine that is capable of detecting Earthmass planets in the habitable zones of low-mass stars.
Science:
- RV follow-up of small transiting planet candidates to
confirm them and measure their masses.
- Taking the census of habitable worlds in the solar
neighborhood.
Team:
U. Chicago led instrument development with Harvard as
Magellan sponsor.
Timescale:
4 year project; first light June 2018.
Funding:
- Total cost is $4.5M.
- $1.2M U. Chicago internal funds available now to begin the
project.
Example Science Case:
Study of Habitable Exoplanets
Compared to Sun-like stars,
habitable-zone planets
around M dwarfs:
• Yield larger RV signals
• Yield larger transit
signals
• Have higher transit
probabilities
• Transit more frequently
Current State of Exoplanet Transit Spectroscopy
GJ 1214b
Kreidberg, Bean, et al. 2014, Nature
The first exoplanet spectrum sensitive to an Earth-like composition
atmosphere.
Sensitive measurements only possible because the planet orbits a small star
(signal goes as R*-2).
Towards Other Earths
real data!
GJ 1214b
Rp = 2.7 RE
T = 580 K
2014
Kreidberg et al.
precision = 30 ppm
simulated data
Earth 2.0
2018
precision = 10 ppm
Rp = 1.0 RE
T = 300 K
N2-rich, trace H2O atmosphere
Towards Other Earths
NASA’s TESS mission (led by MIT)
will be launched in 2017 to find the
small transiting planets that can be
characterized.
There is no existing instrument
capable of confirming and
measuring the masses of the small
exoplanets expected to be
discovered in the habitable zones of
low-mass stars.
The main issue is the faintness of
the stars at the wavelengths where
high-precision radial velocity
measurements are typically made.
MAROON-X Concept
Science requirements:
• RV semi-amplitude of an Earth-mass planet orbiting in the habitable zone of
a low-mass star is 1 m s-1.
• Expectation for the distribution of such transiting planets suggests we need
to be able to efficiently observe stars with V = 16.5 (d = 20 pc).
MAROON-X Concept
MAROON-X Concept
Core spectrograph will
be a Kiwispec R4-100.
Kiwispec prototype in the lab
MAROON-X at Magellan
• MAROON-X will be a PI instrument that is built by Bean’s group at U.
Chicago.
• Harvard is sponsoring the instrument for installation and use at
Magellan.
• The instrument must be housed in a climate-controlled box (12’ x 20’
footprint) away from the telescopes.
• It can be fed via fiber optic from any available port.
• Minimal impact to Observatory operations (e.g., closed-cycle coolers,
fixed instrument, only rare intervention by PI’s group).
• Preliminary science consortium includes 8 senior scientists from
Chicago, CfA, and MIT. Other interested scientists at Magellan are
welcome to join.
MAROON-X Funding
• Total cost: $4.5M
• MRI proposal submitted January 2013. Not selected for funding,
but the panel gave very encouraging feedback.
• No U. Chicago MRI slot for 2014 due to internal politics.
• $1.2M in U. Chicago internal funds available now to start the
project.
• Remaining funding will be sought through a combination of
private (foundations, fellowships, etc.) and public (NSF) sources.
MAROON-X Status
• A PDR with external experts will be scheduled for April 2014.
• If the PDR outcome is positive then we will order a scaled-back
version of the Kiwispec R4-100 (single arm, cheap detector and
camera) and begin work on the front end and stabilization.
• On track for first light in 2018.