MAROON-X: An instrument for identifying another Earth

David Charbonneau (Harvard)Jacob Bean (U. Chicago)

Concept: A radial velocity machine that is capable of detecting Earth- mass 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.

Summary

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

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).

Kreidberg, Bean, et al. 2014, Nature

GJ 1214b

Current State of Exoplanet Transit Spectroscopy

GJ 1214bRp = 2.7 RE T = 580 K

2014 Kreidberg et al.

precision = 30 ppm

2018precision = 10 ppm

N2-rich, trace H2O atmosphere

Towards Other Earths

Earth 2.0Rp = 1.0 RE

T = 300 K

real data!

simulated data

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.

Towards Other Earths

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.