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NASA Solicitation
To Join the Large Binocular Telescope Interferometer Science Team to Conduct Investigations of ExoZodiacal Dust Around Nearby Stars

Frequently Asked Questions

If you have questions about the call, please contact Dr. Rafael Millan-Gabet (NASA-LBTI Project Scientist) at Submitted questions and responses will be posted below; please scroll to the bottom of the page to see the most recently posted questions.

Proposals are due Friday, April 27, 2012, 5 pm PDT

Q: Can you clarify whether the LBTI call is for individuals only, or can one apply as part of a small team? What will be the roles of the proposal PI and collaborators?


The intent of this call for proposals is to select a small focused team to carry out a key science program. We expect 3-4 PIs will be selected, covering specific areas of expertise as described in the call. The LBTI project scientist (Phil Hinz) plus the selected PIs will constitute the key science team, and this group will be solely responsible for science deliberations, target selection, observations, data processing and analysis and publications in peer-reviewed journals.

We discourage proposals which attempt to cover all the areas of needed expertise under a single PI. The selection committee will be at liberty to select a PI as science team representative for only a subset of the expertise areas proposed.

There is no formal co-Investigator role for the proposals being solicited. The science team may invite proposal collaborators to have a subsidiary role in specific areas of expertise. In addition, PIs may work with their own students or postdocs to fulfill their role on the science team.

Q: Are there limitations as to how many collaborators a proposal can include?

A: No. However, relatively small teams are best aligned with the spirit of this call.

Q: Since the available funding will be distributed among the selected PIs, is a proposal with many collaborators more likely to be selected, since it provides more workforce for the "same price"?

A: No. A proposal should contain only collaborators that are necessary in order to perform the activities proposed.

Q: One concern I have is that the exozodi report from the Exoplanet Exploration Program Analysis Group (ExoPAG) is not available to those who have not been on that particular Science Analysis Group, and so this is a potentially competitive disadvantage for this group of individuals.

A: The ExoPAG report is now available here.

Q: What data products are being provided to the observers? Or should proposers assume that they would be involved in the pipeline development and help generate the data products as well as the analysis results?

A: Finalizing the development of the LBTI nulling pipeline will likely take place in parallel with the first few months of observations. A proposer can certainly say that they are in a position to contribute to that task.

Q: Will NExScI be willing to send funding to PI and collaborator(s) at different institutions?

A: In general, no. NExScI will send funds only to the proposal PI (the PI is then free to distribute the award among the proposal collaborators according to the rules of the institutions involved). The only exception will be for collaborators who are employed at a NASA center as they cannot accept money from other institutions. In this case, NExScI will make a limited number of distributions to NASA centers via NASA HQ based on allocation guidelines from the PI.

Q: Can a PI at a foreign institution still submit a proposal although he/she will not qualify for funding?

A: Yes.

Q: Can you point to some preliminary LBTI results?

A: There are no interferometry results yet (commissioning is under way) but two papers have been recently submitted based on LBTI data:

HD15115 debris disk.

HR8799 planet imaging.

Q: If I am not successful in being part of the LBTI Science Team, will the LBTI data be archived and public so I can access them?

A: Yes the data will be archived at NExScI and will be made public when the proprietary period expires (currently under negotiation but likely to be 3 years + 6 months after the start of the survey in Fall 2012).

Q: What role do NExScI scientists have in the execution of the LBTI exozodi program? Will they staff observing runs and provide basic calibrated data to the science team, as they did for the 3 Keck Interferometer Nuller key science projects? Or will these functions be totally the responsibility of the selected LBTI exozodi science team?

A: The NASA-LBTI project scientist (Rafael Millan-Gabet, NExScI) will work with the exozodi science team. Observing runs will be staffed by the LBTI group at the University of Arizona. Science team members are welcome to participate in observing runs, subject to space limitations at the observatory. As stated above, the LBTI data pipeline is under development. Science team members can play a role in evaluating early data products. Once finalized, calibrated data from the pipeline will be available to the science team and archived and eventually publicly distributed at NExScI.

Q: What spectral filters are available?

A: The LBTI nulling camera has a variety of narrow band filters from 7.5 to 13 microns. It also has a grism which gives R=75 at the center of the N band for a 0.25 arcsec diffraction width. Please contact for technical details.

Q: I find no mention of LMIRCam on the NASA solicitation web site. Only the 10 micron nuller is described. Will LMIRCam be part of the instrument suite available for ExoZodiacal Dust Science proposals? What about the interferometric imaging mode at 10 micron?

A: The main exozodi survey will be conducted using the Mid-IR Nulling mode, and for the purposes of this solicitation proposers should consider this the focus. However the science team will be free to consider use of the LMIRCam (3-5 microns) or the N-band interferometric imaging mode for some targets for purposes of enhancing the exozodi results.

Q: When can the science team members expect to have calibrated data ready for modeling?

A: The LBTI is currently being commissioned. Science operations are expected to start in Fall 2012. However, it is reasonable to expect that the instrument performance will evolve during the first few months of science operations, as well as the implementation of optimum observing strategies and data reduction methods. Full capabilities may not be available until early 2013. The selected team members should therefore be prepared to adapt to these uncertainties inherent to the initial operations of a new instrument.

Q: Will the LBTI nulling instrument produce images of the exozodi disks?

A: In general, no. The LBT nulling interferometer is a pupil-plane interferometer, with a spatial resolution given by the 14.4 m center-to-center separation of the two LBT telescopes. The main observable therefore will be the "null leakage", produced by dust flux transmitted through the narrow interference fringes (e.g. 140 milliarcseconds fringe spacing at 10 microns). The optical configuration is such that a single-telescope image is also produced, which may be useful in cases where there is dust emission resolved by the individual telescopes. In order to understand the response of the LBT nulling interferometer, we recommend the Hinz et al. 1998 reference given in the references section.

updated April 25, 2012