Commissioning and on-sky performance verification of iLocater

Marshall C. Johnson; Marcelo Tala Pinto; Jonathan Crass; Brian Sands; Jackson Datkuliak; Sai Vidyud Senthil Nathan; Justin R. Crepp; Michael Engelman; Daniel Pappalardo; Julia Brady; Mark Derwent; Xavier Lesley-Saldaña; Andrew Bechter; Eric Bechter; Christian Schwab; David Aikens; Chad Bender; Chris Brandon; Cynthia Brooks; Matheus J. Castro; Jeffrey Chilcote; Al Conrad; Gregory Delo; Erin Duell; Matthew Engstrom; Steve Ertel; Louis Fantano; John Keith Feggans; Hali Flores; B. Scott Gaudi; David King; Ondrej Kitzler; Kaitlin M. Kratter; Jeffrey Kruk; Thomas Legero; Stanimir Letchev; Jerry Mason; Joaquin Mason; Matthew Misch; Jacob Pember; Richard Pogge; Andreas Quirrenbach; Joshua Schlieder; Augustyn Waczynski; Joseph Shields; Daewook Kim; Mark Smithwright; Allie Renshaw; Austin Richie; Alexa Rizika; Nandini Sadagopan; Jonathan Shover; James E. Smous; Jayde Spiegel; Julian Stürmer; Sahil Sura; Robert Buechel; Joe Thomes; Ji Wang; Lauren M. Weiss; Daniel J Wilson; Dane Zielinski-Nicolson

doi:10.1117/12.3105457

Commissioning and on-sky performance verification of iLocater

Marshall C. Johnson, Marcelo Tala Pinto, Jonathan Crass, Brian Sands, Jackson Datkuliak, Sai Vidyud Senthil Nathan, Justin R. Crepp, Michael Engelman, Daniel Pappalardo, Julia Brady, Mark Derwent, Xavier Lesley-Saldaña, Andrew Bechter, Eric Bechter, Christian Schwab, David Aikens, Chad Bender, Chris Brandon, Cynthia Brooks, Matheus J. CastroJeffrey Chilcote, Al Conrad, Gregory Delo, Erin Duell, Matthew Engstrom, Steve Ertel, Louis Fantano, John Keith Feggans, Hali Flores, B. Scott Gaudi, David King, Ondrej Kitzler, Kaitlin M. Kratter, Jeffrey Kruk, Thomas Legero, Stanimir Letchev, Jerry Mason, Joaquin Mason, Matthew Misch, Jacob Pember, Richard Pogge, Andreas Quirrenbach, Joshua Schlieder, Augustyn Waczynski, Joseph Shields, Daewook Kim, Mark Smithwright, Allie Renshaw, Austin Richie, Alexa Rizika, Nandini Sadagopan, Jonathan Shover, James E. Smous, Jayde Spiegel, Julian Stürmer, Sahil Sura, Robert Buechel, Joe Thomes, Ji Wang, Lauren M. Weiss, Daniel J Wilson, Dane Zielinski-Nicolson

School of Mathematical and Physical Sciences

Research output: Chapter in Book/Report/Conference proceeding › Conference proceeding contribution › peer-review

Abstract

iLocater is a high-resolution near-infrared extreme precision radial velocity (EPRV) spectrograph that was deployed to the Large Binocular Telescope (LBT) in June 2026. iLocater operates over λ = 966-1312 nm with a median resolving power of R = 205, 000 as measured in the laboratory. We present the commissioning and initial on-sky verification program using solar and night-time observations at the LBT. First light was achieved on 27 June 2026, and nearly 150 on-sky spectra have now been recorded. Observations include single stars ranging in spectral type from B5 to M6. iLocater uses the LBT AO system, and we have demonstrated its ability to obtain spatially resolved spectra of close (θ < 1") binary stars.

Original language	English
Title of host publication	Ground-based and Airborne Instrumentation for Astronomy XI
Editors	Joël R. D. Vernet, Julia J. Bryant, Kentaro Motohara
Place of Publication	Bellingham, Washington
Publisher	SPIE
Pages	141494W-1-141494W-12
Number of pages	12
DOIs	https://doi.org/10.1117/12.3105457
Publication status	Published - 21 Aug 2026
Event	Ground-based and Airborne Instrumentation for Astronomy XI - Copenhagen, Denmark Duration: 5 Jul 2026 → 11 Jul 2026

Publication series

Name	Proceedings of SPIE
Volume	14149
ISSN (Print)	0277-786X
ISSN (Electronic)	1996-756X

Conference

Conference	Ground-based and Airborne Instrumentation for Astronomy XI
Country/Territory	Denmark
City	Copenhagen
Period	5/07/26 → 11/07/26

Keywords

Extremely Precise Radial Velocities
Spectrograph
Adaptive Optics
Exoplanets
Near-Infrared
High Resolution Spectroscopy

Access to Document

10.1117/12.3105457

Cite this

Johnson, M. C., Pinto, M. T., Crass, J., Sands, B., Datkuliak, J., Nathan, S. V. S., Crepp, J. R., Engelman, M., Pappalardo, D., Brady, J., Derwent, M., Lesley-Saldaña, X., Bechter, A., Bechter, E., Schwab, C., Aikens, D., Bender, C., Brandon, C., Brooks, C., ... Zielinski-Nicolson, D. (2026). Commissioning and on-sky performance verification of iLocater. In J. R. D. Vernet, J. J. Bryant, & K. Motohara (Eds.), Ground-based and Airborne Instrumentation for Astronomy XI (pp. 141494W-1-141494W-12). Article 141494W (Proceedings of SPIE; Vol. 14149). SPIE. https://doi.org/10.1117/12.3105457

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title = "Commissioning and on-sky performance verification of iLocater",

abstract = "iLocater is a high-resolution near-infrared extreme precision radial velocity (EPRV) spectrograph that was deployed to the Large Binocular Telescope (LBT) in June 2026. iLocater operates over λ = 966-1312 nm with a median resolving power of R = 205, 000 as measured in the laboratory. We present the commissioning and initial on-sky verification program using solar and night-time observations at the LBT. First light was achieved on 27 June 2026, and nearly 150 on-sky spectra have now been recorded. Observations include single stars ranging in spectral type from B5 to M6. iLocater uses the LBT AO system, and we have demonstrated its ability to obtain spatially resolved spectra of close (θ < 1{"}) binary stars.",

keywords = "Extremely Precise Radial Velocities, Spectrograph, Adaptive Optics, Exoplanets, Near-Infrared, High Resolution Spectroscopy",

author = "Johnson, \{Marshall C.\} and Pinto, \{Marcelo Tala\} and Jonathan Crass and Brian Sands and Jackson Datkuliak and Nathan, \{Sai Vidyud Senthil\} and Crepp, \{Justin R.\} and Michael Engelman and Daniel Pappalardo and Julia Brady and Mark Derwent and Xavier Lesley-Salda{\~n}a and Andrew Bechter and Eric Bechter and Christian Schwab and David Aikens and Chad Bender and Chris Brandon and Cynthia Brooks and Castro, \{Matheus J.\} and Jeffrey Chilcote and Al Conrad and Gregory Delo and Erin Duell and Matthew Engstrom and Steve Ertel and Louis Fantano and Feggans, \{John Keith\} and Hali Flores and Gaudi, \{B. Scott\} and David King and Ondrej Kitzler and Kratter, \{Kaitlin M.\} and Jeffrey Kruk and Thomas Legero and Stanimir Letchev and Jerry Mason and Joaquin Mason and Matthew Misch and Jacob Pember and Richard Pogge and Andreas Quirrenbach and Joshua Schlieder and Augustyn Waczynski and Joseph Shields and Daewook Kim and Mark Smithwright and Allie Renshaw and Austin Richie and Alexa Rizika and Nandini Sadagopan and Jonathan Shover and Smous, \{James E.\} and Jayde Spiegel and Julian St{\"u}rmer and Sahil Sura and Robert Buechel and Joe Thomes and Ji Wang and Weiss, \{Lauren M.\} and Wilson, \{Daniel J\} and Dane Zielinski-Nicolson",

year = "2026",

month = aug,

day = "21",

doi = "10.1117/12.3105457",

language = "English",

series = "Proceedings of SPIE",

publisher = "SPIE",

pages = "141494W--1--141494W--12",

editor = "Vernet, \{Jo{\"e}l R. D.\} and Bryant, \{Julia J.\} and Kentaro Motohara",

booktitle = "Ground-based and Airborne Instrumentation for Astronomy XI",

address = "United States",

note = "Ground-based and Airborne Instrumentation for Astronomy XI ; Conference date: 05-07-2026 Through 11-07-2026",

}

Johnson, MC, Pinto, MT, Crass, J, Sands, B, Datkuliak, J, Nathan, SVS, Crepp, JR, Engelman, M, Pappalardo, D, Brady, J, Derwent, M, Lesley-Saldaña, X, Bechter, A, Bechter, E, Schwab, C, Aikens, D, Bender, C, Brandon, C, Brooks, C, Castro, MJ, Chilcote, J, Conrad, A, Delo, G, Duell, E, Engstrom, M, Ertel, S, Fantano, L, Feggans, JK, Flores, H, Gaudi, BS, King, D, Kitzler, O, Kratter, KM, Kruk, J, Legero, T, Letchev, S, Mason, J, Mason, J, Misch, M, Pember, J, Pogge, R, Quirrenbach, A, Schlieder, J, Waczynski, A, Shields, J, Kim, D, Smithwright, M, Renshaw, A, Richie, A, Rizika, A, Sadagopan, N, Shover, J, Smous, JE, Spiegel, J, Stürmer, J, Sura, S, Buechel, R, Thomes, J, Wang, J, Weiss, LM, Wilson, DJ & Zielinski-Nicolson, D 2026, Commissioning and on-sky performance verification of iLocater. in JRD Vernet, JJ Bryant & K Motohara (eds), Ground-based and Airborne Instrumentation for Astronomy XI., 141494W, Proceedings of SPIE, vol. 14149, SPIE, Bellingham, Washington, pp. 141494W-1-141494W-12, Ground-based and Airborne Instrumentation for Astronomy XI, Copenhagen, Denmark, 5/07/26. https://doi.org/10.1117/12.3105457

Commissioning and on-sky performance verification of iLocater. / Johnson, Marshall C.; Pinto, Marcelo Tala; Crass, Jonathan et al.
Ground-based and Airborne Instrumentation for Astronomy XI. ed. / Joël R. D. Vernet; Julia J. Bryant; Kentaro Motohara. Bellingham, Washington: SPIE, 2026. p. 141494W-1-141494W-12 141494W (Proceedings of SPIE; Vol. 14149).

Research output: Chapter in Book/Report/Conference proceeding › Conference proceeding contribution › peer-review

TY - GEN

T1 - Commissioning and on-sky performance verification of iLocater

AU - Johnson, Marshall C.

AU - Pinto, Marcelo Tala

AU - Crass, Jonathan

AU - Sands, Brian

AU - Datkuliak, Jackson

AU - Nathan, Sai Vidyud Senthil

AU - Crepp, Justin R.

AU - Engelman, Michael

AU - Pappalardo, Daniel

AU - Brady, Julia

AU - Derwent, Mark

AU - Lesley-Saldaña, Xavier

AU - Bechter, Andrew

AU - Bechter, Eric

AU - Schwab, Christian

AU - Aikens, David

AU - Bender, Chad

AU - Brandon, Chris

AU - Brooks, Cynthia

AU - Castro, Matheus J.

AU - Chilcote, Jeffrey

AU - Conrad, Al

AU - Delo, Gregory

AU - Duell, Erin

AU - Engstrom, Matthew

AU - Ertel, Steve

AU - Fantano, Louis

AU - Feggans, John Keith

AU - Flores, Hali

AU - Gaudi, B. Scott

AU - King, David

AU - Kitzler, Ondrej

AU - Kratter, Kaitlin M.

AU - Kruk, Jeffrey

AU - Legero, Thomas

AU - Letchev, Stanimir

AU - Mason, Jerry

AU - Mason, Joaquin

AU - Misch, Matthew

AU - Pember, Jacob

AU - Pogge, Richard

AU - Quirrenbach, Andreas

AU - Schlieder, Joshua

AU - Waczynski, Augustyn

AU - Shields, Joseph

AU - Kim, Daewook

AU - Smithwright, Mark

AU - Renshaw, Allie

AU - Richie, Austin

AU - Rizika, Alexa

AU - Sadagopan, Nandini

AU - Shover, Jonathan

AU - Smous, James E.

AU - Spiegel, Jayde

AU - Stürmer, Julian

AU - Sura, Sahil

AU - Buechel, Robert

AU - Thomes, Joe

AU - Wang, Ji

AU - Weiss, Lauren M.

AU - Wilson, Daniel J

AU - Zielinski-Nicolson, Dane

PY - 2026/8/21

Y1 - 2026/8/21

N2 - iLocater is a high-resolution near-infrared extreme precision radial velocity (EPRV) spectrograph that was deployed to the Large Binocular Telescope (LBT) in June 2026. iLocater operates over λ = 966-1312 nm with a median resolving power of R = 205, 000 as measured in the laboratory. We present the commissioning and initial on-sky verification program using solar and night-time observations at the LBT. First light was achieved on 27 June 2026, and nearly 150 on-sky spectra have now been recorded. Observations include single stars ranging in spectral type from B5 to M6. iLocater uses the LBT AO system, and we have demonstrated its ability to obtain spatially resolved spectra of close (θ < 1") binary stars.

AB - iLocater is a high-resolution near-infrared extreme precision radial velocity (EPRV) spectrograph that was deployed to the Large Binocular Telescope (LBT) in June 2026. iLocater operates over λ = 966-1312 nm with a median resolving power of R = 205, 000 as measured in the laboratory. We present the commissioning and initial on-sky verification program using solar and night-time observations at the LBT. First light was achieved on 27 June 2026, and nearly 150 on-sky spectra have now been recorded. Observations include single stars ranging in spectral type from B5 to M6. iLocater uses the LBT AO system, and we have demonstrated its ability to obtain spatially resolved spectra of close (θ < 1") binary stars.

KW - Extremely Precise Radial Velocities

KW - Spectrograph

KW - Adaptive Optics

KW - Exoplanets

KW - Near-Infrared

KW - High Resolution Spectroscopy

U2 - 10.1117/12.3105457

DO - 10.1117/12.3105457

M3 - Conference proceeding contribution

T3 - Proceedings of SPIE

SP - 141494W-1-141494W-12

BT - Ground-based and Airborne Instrumentation for Astronomy XI

A2 - Vernet, Joël R. D.

A2 - Bryant, Julia J.

A2 - Motohara, Kentaro

PB - SPIE

CY - Bellingham, Washington

T2 - Ground-based and Airborne Instrumentation for Astronomy XI

Y2 - 5 July 2026 through 11 July 2026

ER -

Commissioning and on-sky performance verification of iLocater

Abstract

Publication series

Conference

Keywords

Access to Document

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