KECK INSTITUTE FOR SPACE STUDIES

       

Workshop: Exploring Exoplanets with Interferometry

November 28 - December 2, 2022
California Institute of Technology - Pasadena, CA 91125

Map

Workshop Overview:

Given that interferometry is becoming the technique of choice for directly detecting and characterizing the bulk of exoplanets from the ground in the near future (before ELTs) and given the prospects of upcoming and future instruments (VLTI/GRAVITY+ , VLTI/Hi-5, Keck/VFN, LIFE mission), a workshop bringing the community together to determine the best path forward is warranted.

The workshop will focus on new concepts for interferometric observations for exoplanet research including: how new micro-thruster technologies and innovative, new low cost spacecraft might enable separated spacecraft concepts such as the new Large Interferometer for Exoplanets (LIFE) mission now under study by ESA; how novel materials may allow the use of integrated optics for interferometric recombination in the MIR; how low-noise, high QE MIR detector technologies can be further advanced; how near-term high dynamic range interferometric efforts on ground-based telescopes can demonstrate new technologies relevant to space-based missions; how interferometric astrometry on separated spacecraft might take advantage of new technological approaches to achieve the <0.1 micro-arcsec precision needed to detect and characterize the masses and orbits of Earth analogs otherwise not detectable via the RV technique.

In this context, the aim of our workshop is to address the following questions:

  • What are the immediate next steps required to enable space-based interferometry, including a possible smallsat formation flying pathfinder?
  • How can ground-based interferometry help test and develop some of the key technologies and new ideas paving the way to a future space mission like LIFE? How do we support such developments?
  • How do we overcome the limitations currently preventing us from detecting exoplanets within the diffraction limit of individual telescopes using interferometry?
  • How do we best incorporate and further develop state-of-the-art technologies (e.g., photonics-based beam combination, precision formation flying, advanced data processing techniques and low noise ultra-stable MIR detectors) to maximize the success of a future space-based mission like LIFE?
  • Could a space interferometry mission optimized for the direct characterization of exo-Earths also provide precise enough stellar astrometry to determine planet masses?

We will also use the workshop setting to begin coordinating follow-up research activities, including numerical and optical studies, grant writing, and dissemination of results.


Monday, November 28, 2022
Keck Center Think Tank, Room 155

Short Courses: Exoplanet Science Meets Interferometry
Foundational Interdisciplinary Lectures

Time
Event
Speaker
7:30 - 8:15  Institute opens early for workshop check in, SHOW PROOF OF VACCINATION, take your rapid test, affirm you are not symptomatic nor have had contact with anyone who is, pick up badge and welcome packet, find seat in the Think Tank
8:15 - 8:45 Enjoy coffee and breakfast in the Keck Center courtyard
8:45 - 9:15 Quick Welcome and Participant Introductions (1 minute) Bertrand Mennesson / Chas Beichman
Short Course #1 - Exoplanet Science Motivations for a mid-IR LIFE-like Mission 
9:15 - 9:35 Searching for Life: General Motivation and Approaches
(video) (.pdf slides)
Tiffany Kataria
9:35 - 9:45 Rocky Exoplanet Science with Ground-Based ELTs
(video) (.pdf slides)
Dimitri Mawet
9:45 - 9:55 The Promises of an IROUV-like Future Flagship for Rocky Exoplanet Science
(video) (.pdf slides)
Bertrand Mennesson
9:55 - 10:15 The Necessity for a Multi-Technique Approach to Rocky Exoplanet Characterization
(video) (.pdf slides)
Chas Beichman
10:15 - 10:35 The LIFE Initiative - Science Prospects and Challenges
(video) (.pdf slides)
Sascha Quanz
10:35 - 10:45 Discussion - Q&A All
10:45 - 11:15 Break
Short Course #2 -  Primer on Science and Technology from Interferometry
11:15 - 12:15 Introduction to Interferometry
(video) (.pdf slides)
Gerard van Belle  
12:15 - 12:30 Challenges/ Advantages of Interferometry from the Ground
(video) (.pdf slides)
Gautam Vasisht
12:30 - 12:45 Challenges/ Advantages of Interferometry from Space
(video) (.pdf slides)
Charles Beichman
12:45 - 2:15 Short Course Ends: Lunch at Athenaeum
Workshop
2:15 - 2:45 Workshop Logistics and Introduction to KISS Michele Judd
2:45 - 3:30 Study Vision and Goals for this Workshop Team Leads
3:30 - 4:00 Break
WG 1: Precursor Science Investigations: Theory
4:00 - 4:25 Atmospheric Retrievals as a Tool to Define the Requirements for LIFE Eleonora Alei
4:25 - 4:50 Habitability in Relation to Atmospheric Diversity Michael Meyer
4:50 - 5:30 Discussion:
- What would you need from the instrument team to further refine your studies? Connection between science and what you would want the instrument to do?
- Opacity?
- Synergistic observations IROUV + LIFE
- How important is it to go to 4.5 microns to detect methane feature for LIFE? From a strategic point of view, how convenient is for LIFE to rely on IROUV for the detection of CH4 instead of being self-sufficient (e.g., going to 4.5 microns)?

Deliverable:
Science Requirements towards Mission Requirements as a function of science question (Andrea’s diagram)
Tiffany Kataria
and
Eleonora Alei
5:30 - 6:00 Pack up and walk to the Athenaeum All
6:00 Dinner at the Athenaeum

Tuesday, November 29, 2022
Keck Center - Think Tank, Room 155

Draw me a Nuller

Time
Event
Speaker
8:00 - 8:30 Institute Opens - FREE THINK TIME
Check in, affirm you are not symptomatic nor have had contact with anyone who is
8:30 - 9:00 Enjoy coffee and breakfast in the Keck Center courtyard
9:00 - 9:05 Logistics and Team Lead Goals for the Day Michele Judd / Team Leads
WG 2: Precursor Science - Observations
9:05 - 9:10 Introduction, what is precursor science? Steve Ertel
9:10 - 9:20 Review of IROUV precursor science, anything missing for LIFE?  Incl. Exoplanet demographics vs. host star Michael Meyer
9:20 - 9:30 Ground-based imaging of HZ planets, synergies with Roman CGI, JWST, etc. Kevin Wagner
9:30 - 9:40 Space-based imaging of planets with SPICE Taro Matsuo
9:40 - 9:50 Exozodiacal dust Steve Ertel
9:50 - 10:00 Transit spectroscopy  (& transit planet searches?) with focus on mid-IR transit spectra.  ARIEL.  Note on CHEOP Andrea Fortier
10:00 - 10:10 How to avoid blind searches  (EPRV, astrometry, Gaia precision on bright stars?) Michael Meyer
10:10 - 10:30 Plenary Discussion:
Scrutinize the IROUV precursor science topics, evaluate the relevance of the items on this list for LIFE
Create and prioritize a list of LIFE-specific precursor observations
Steve Ertel
10:30 - 11:00 Break
WG 4: Nulling Architecture, Beam Transport and Nulling Approach
11:00 - 11:01 Session Scope Eugene Serabyn
11:01 - 11:06 Short Performance requirements recap Andrea Fortier / Felix A. Dannert
11:06 - 11:23 Configuration architecture history Bertrand Mennesson
11:23 - 11:40 Configuration architecture: recent LIFE developments; LIFE error budget Jonah Hansen
11:40 - 11:45 Lessons learned from JWST about beam quality, scattering, background Chas Beichman
11:45 - 11:50 Why/when use modal filtering (note: not spatial filter HW)       Bertrand Mennesson
11:50 - 12:00 Nulling beam combiner overview  (incl adaptive nuller) and null depth levels    Eugene Serabyn
12:00 - 12:10 LBTI/ground-based nullers (HW, incl. dispersion corr)        Steve Ertel
12:10 - 12:20 Potential LIFE nulling beam combiner architecture    Michael Ireland
12:20 - 12:30 NICE (Nulling Interferometry Cryogenic Experiment) Adrian Glauser
12:30 - 2:00 Group Picture and Lunch at the Athenaeum
2:00 - 2:15 Selection of possible third break out session topic All
2:15 - 3:45 Break out Discussion WG 2: Precursor Science Investigations: Observations
Scrutinize the IROUV precursor science topics, evaluate the relevance of the items on this list for LIFE. Create and prioritize a list of LIFE-specific precursor observations.
Steve Ertel + Breakout Group A
2:15 - 3:45 Break out Discussion WG 4: Nulling architecture, beam transport and nulling approach
1 - What is the best set of metrics for the overall nulling architecture?
2- What should/might a (non-integrated optics) nulling beamcombiner look like?
Is bulk optics (other than spatial filter) a reasonable baseline, especially for longer wavelengths?
What is a reasonable wavelength range for a single nuller? i.e. how many null channels does LIFE need? (will be critical for cost). NB this relates to the wavelength range of an adequate spatial filter.
How coupled are the architecture and the beamcombiner? Can we lock in a general spacecraft architecture (e.g. Emma X-array like design, but where there may be >4 telescopes or a different configuration) without finalising an exact nulling architecture?
Eugene Serabyn + Breakout Group B
2:15 - 3:45 Break out Discussion #3: TBD topic Break out Group C
3:45 - 4:15 Break
4:15 - 5:30 Breakout group reports (10 mins each)
Discussion
Break out groups
5:30 - 7:30 POSTERish SESSION and Informal food truck dinner at the Keck Center
(dinner starts at 6:30 pm)

Wednesday, November 30, 2022
Keck Center - Think Tank, Room 155

Key Technologies for Space Interferometry

Time
Event
Speaker
8:00 - 8:30 Institute Opens - FREE THINK TIME
Take your rapid test if you did not take it in your hotel or at home, check in, affirm you are not symptomatic nor have had contact with anyone who is
8:30 - 9:00 Enjoy coffee and breakfast in the Keck Center courtyard
9:00 - 9:05 Logistics and Team Lead Goals for the Day Michele Judd / Team Leads
WG #3: Free fliers and Technology
9:05 - 9:20 Technical Requirements for LIFE, with a focus on free flying architectures Michael Ireland
9:20 - 9:35 Lessons from TPF free fliers Daniel Scharf (v)
9:35 - 9:50 Lessons from Free Flying missions Leonid Pogorelyuk
9:50 - 10:10 Funded missions that are relevant but not interferometry John Monnier
10:10 - 10:20 Unfunded space interferometry missions being developed (one slide each) TBD
10:20 - 10:30 Callback talk to the TRLs in talk (1) and what shape we are in.
What needs to be done next
Taro Matsuo
10:30 - 11:00 Break
WG 5: LIFE Technology: Integrated Optics and Interferometric Functions
11:00 - 11:10 Topic introduction (GRAVITY, mid-IR tech, spatial filtering) Jean-Philippe Berger
11:10 - 11:20 Recent short wavelength photonics nulling experiments Romain Laugier
11:20 - 11:30 L band Photonics in ASGARD-NOTT Denis Defrère
11:30 - 11:40 Kernel Nuller conceptsin photonics - laser inscription  Michael Ireland
11:40 - 11:50 Mid-IR photonics at ETH Adrian Glauser
11:50 - 12:00 LIFE-5 Guyon like combiner concept Jonah Hansen
12:00 - 12:30 Plenary discussion All
12:30 - 2:00  Lunch at the Athenaeum
2:00 - 2:15 Selection of possible topics for Break out sessions #2 and #3 All
2:15 - 3:45 Break out Discussion WG 3: Free fliers and associated technology
Which technical requirements were missing?
How different (more difficult) are requirements for non-nulling missions.                               
How many key technology gaps associated with free fliers can genuinely be advanced in smaller missions? (not freeflying)                               
Can we agree on the simplest possible baseline required technology set?
Michael Ireland + Breakout Group A
2:15 - 3:45 Break out Discussion #2: TBD topic Breakout Group B
2:15 - 3:45 Break out Discussion #3: TBD topic Breakout Group C
3:45 - 4:15 Break
4:15 - 5:30 Breakout group reports (10 mins each)
Discussion
Break out groups
5:30 Personal Think Time / Spontaneous Discussions All
6:00 No-host dinner in Pasadena (optional, organized by team lead)

Thursday, December 1, 2022
Keck Center - Think Tank, Room 155

Breaking the Diffraction Limit of Exoplanet Direct Detection from the Ground and Space

Time
Event
Speaker
8:00 - 8:30 Institute Opens - FREE THINK TIME
Check in, affirm you are not symptomatic nor have had contact with anyone who is
8:30 - 9:00 Enjoy coffee and breakfast in the Keck Center courtyard
9:00 - 9:05 Logistics and Team Lead Goals for the Day Michele Judd / Team Leads
WG 6: Nulling Data reduction and its impact on mission design
9:05 - 9:25 Precision Nulling with NSC Bertrand Mennesson
9:25 - 9:45 High dispersion Nulling with KPIC/VFN (and ELTs, and limitations) Dimitri Mawet
9:45 - 10:05 Interferometric chopping and kernel nulling Romain Laugier
10:05 - 10:25 Science instrument null servos Michael Ireland
10:25 - 10:30 Discussion All
10:30 - 11:00 Break
WG 7: High Contrast Ground-based Interferometry
11:00 - 11:20 Exoplanet characterization and astrometry with VLTI/GRAVITY
(15 +5)
Mathias Nowak (v)
11:20 - 11:40 Precision closure phases and astrometric detection of exoplanets at CHARA and VLTI (15 +5) John Monnier
11:40 - 12:00 Nulling at LBTI (15 +5) Steve Ertel
12:00 - 12:20 Plan for L-band nuller at VLTI (15 +5) Denis Defrère
12:20 - 12:30 Future visions for ground-based interferometry Gail Schaefer / John Monnier
12:30 - 2:00  Lunch on your own
2:00 - 2:15 Breakout group organization All
2:15 - 3:45 Break out Discussion WG 6:  Nulling Data reduction and its impact on mission design
Data acquisition strategy/architecture: what is the best strategy for a space nuller? Waveband splitting? Is phase chopping needed?
Data reduction: what are the needs / requirements? Can we extend the NSC to chopped nuller? 
Signal processing: What are the current strategies for signal extraction?
What studies/analyses are currently missing? (e.g., multi-planetary systems, exozodis, background contamination sources)
PCA background subtraction in nulling. Does it apply to single-mode nuller? 
Denis Defrère + Breakout Group A
2:15 - 3:45 Break out Discussion WG 7:  High Contrast interferometry from the ground
What is the current state-of-the-art in terms of detection limits vs separation?
What are the current limitations (e.g. polarization effects, dispersion issues)?
What are the new instruments promises (Gravity+, Keck VFN, Asgard/NOTT, high res nulling, precise Closure phase).
What do we want to achieve in the future (exoplanet spectroscopy, astrometry, exoplanet sizes, exoplanet imaging, planet formation, etc)?           
Gail Schaefer + Breakout Group B
2:15 - 3:45 Break out Discussion #3: Toward a Precursor Space Demo Michael Ireland + Break out Group C
3:45 - 4:15 Break
4:15 - 5:30 Breakout group reports (10 mins each)
Discussion
Breakout Groups
5:30 Personal Think Time / Spontaneous Discussions All
6:00 Dinner at the Athenaeum 

Friday, December 3, 2022
Keck Center - Think Tank, Room 155

Toward a Precursor Space Demo

Time
Event
Speaker
8:00 - 8:30 Institute Opens - FREE THINK TIME
Check in, affirm you are not symptomatic nor have had contact with anyone who is
8:30 - 9:00 Enjoy coffee and breakfast in the Keck Center courtyard
9:00 - 9:05 Logistics and Team Lead Goals for the Day Michele Judd /
Team Leads
WG #10: "Wide" field-of-view Interferometric (spectro)imaging 
9:05 - 9:15 VLTI, CHARA context Jean-Philippe Berger
9:15 - 9:25 JWST, ELT context Michael Meyer
9:25 - 9:35 Expected Sensitvity and Imaging Capabilities for LIFE and precursors John Monnier
9:35 - 9:45 Technical Solutions for Phase Referencing, "wide field", Astrometry Gautam Vasisht
9:45 - 9:55 Bright Object Science Gail Schaefer
9:55 - 10:05 Faint Object Science Eleonora Alei
10:05 - 10:30 Discussion:
Other science ideas?
How important is phase referencing to LIFE? It has a big effect on architecture and non-exoplanet science.
How important is the non-exoplanet science case anyway? is it maybe even a detriment?
All
10:30 - 11:00 Break
WG #11: Building A Lasting Community
11:00 - 11:20 Lessons from the Darwin/TPF-I Malcolm Fridlund /
Chas Beichman
11:20 - 11:40 Opportunities for Astronomical Programs with LIFE: Outreach to AStronomical Community Gael Schaefer /
Michael Ireland /
Michael Meyer
11:40 - 12:00 Technology and Instrument Opportunties (Ground)--National/International Dimitri Mawet /
John Monnier /
Gerard van Belle
12:00 - 12:30 Technology and Instrument Opportunties (Space) ---National/International Sascha Quanz /
Nicholas Siegler
12:30 - 1:30 Informal box lunch in the Collaboration Courtyard
1:30 - 2:00 Building an Inclusive and long lasting international community for
LIFE in US & Europe
Tiffany Kataria /
Andrea Fortier
2:00 - 2:30 Discussion: Community building All
2:30 - 3:00 Final Report Outline with writing assignments based on 1 final summary chart from each WG All
3:00 - 3:30 Writing session 1: google doc outline, with introduction and initial prose from each WG  All
3:30 - 4:00 Break
4:00 - 4:30 Writing session 2 All
4:30 - 4:45 Team Leads summary Team Leads
4:45 - 5:00 Workshop closeout Michele Judd
5:00 Workshop ends

Workshop Participants:

  • Eleonora Alei - ETH Zürich
  • William Balmer - Johns Hopkins University
  • Chas Beichman - Caltech/JPL
  • Nick Belsten - MIT
  • Jean-Philippe Berger - Institute de Planétologie et d'Astrophysique de Grenoble
  • Felix A. Dannert - ETH Zürich
  • Denis Defrère - KU Leuven
  • Ewan Douglas - University of Arizona
  • Steve Ertel - University of Arizona
  • Andrea Fortier - University of Bern
  • Malcolm Fridlund - Chalmers University of Technology/Leiden University
  • Adrian Glauser - ETH Zürich
  • Jonah Hansen - Australian National University
  • Michael Ireland - Australian National University
  • Tiffany Kataria - JPL
  • Romain Laugier - KU Leuven
  • Taro Matsuo - Nagoya University
  • Dimitri Mawet - Caltech
  • Bertrand Mennesson - JPL
  • Michael Meyer - University of Michigan
  • John Monnier - University of Michigan
  • Rhonda Morgan - JPL
  • Leonid Pogorelyuk - Massachusetts Institute of Technology
  • Sascha Quantz - ETH Zürich
  • Hélène Rousseau - University of Arizona
  • Gail Schaefer - Georgia State University
  • Gene Serabyn - JPL
  • Gerard van Belle - Lowell Observatory
  • Gautam Vasisht - JPL                                                                                                                                         
  • Kevin Wagner - University of Arizona