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MuSCAT3 and MuSCAT4 (Multicolor Simultaneous Camera for studying Atmospheres of Transiting exoplanets) are four channel simultaneous imagers on LCO's 2-meter telescopes FTN at Haleakala Observatory and FTS at Siding Spring Observatory. They have replaced the Spectral imager in September 2020 at FTN, and in October 2023 at FTS.

MuSCAT3 and MuSCAT4 are the third and fourth instruments in a series of multi-channel imagers designed and constructed by the Astrobiology Center in Tokyo (Japan). The P.I. is Norio Narita.

Observing in four channels at once dramatically improves the effective throughput of the telescope, benefiting all science observations. For some science programs, e.g., following-up exoplanet transit observations, there are specific benefits to obtaining truly simultaneous observations in multiple passbands.

The baseline properties of MuSCAT3 and MuSCAT4 are:

  • Passbands: SDSS g' r' i' zs. The filters are fixed; there is no filter wheel.
    • There are deployable narrow-band filters in each band for flux reduction and observing the Na-D line.
  • Cameras: Princeton Instruments Pixis 2048B (r') , 2 x Pixis 2048_eX (g' and i'), Sophia 2048BR (zs')
  • Readout modes: simple imaging and asynchronous time series. The exposure time can be defined per channel.
  • Overheads:
    • 180 sec for telescope slew
    • per readout:
      • 6 / 2.6 seconds ( MUSCAT_FAST mode for Pixis / Sophia camera ).
      • 46 seconds (MUSCAT_SLOW mode).
  • Field of view: ~9.1' x 9.1'
  • Pixel scale: 0.27" / pixel
  • Readnoise: 12 e- ( 17 e- in zs band) in MUSCAT_FAST mode, 3.5 e- in MUSCAT_SLOW mode.
  • Full well: at least 71 ke-, varies by camera from 71 ke- to 120 ke-)
  • Robotic operations in the LCO network.

Support Documents

Combined Acknowledgment of MuSCAT 3 & MuSCAT4

All papers based on MuSCAT3 and / or MuSCAT4 data shall contain the following acknowledgment:

“This paper is based on observations made with the MuSCAT instruments, developed by the Astrobiology Center (ABC) in Japan, the University of Tokyo, and Las Cumbres Observatory (LCOGT). MuSCAT3 was developed with financial support by JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), and is located at the Faulkes Telescope North on Maui, HI (USA), operated by LCOGT. MuSCAT4 was developed with financial support provided by the Heising-Simons Foundation (grant 2022-3611), JST grant number JPMJCR1761, and the ABC in Japan, and is located at the Faulkes Telescope South at Siding Spring Observatory (Australia), operated by LCOGT.“

Acknowledgment of MuSCAT3

All papers based on MuSCAT3 data observed before Oct 19 2023 may use the following acknowledgment in lieu of the combined acknowledgement above:

“This paper is based on observations made with the MuSCAT3 instrument, developed by the Astrobiology Center and under financial supports by JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), at Faulkes Telescope North on Maui, HI, operated by the Las Cumbres Observatory."


The proper reference for the Muscat 3 instrument to cite is Narita et al. 2020, SPIE 11447, 114475K "MuSCAT3: a 4-color simultaneous camera for the 2m Faulkes Telescope North". The same reference should be used for MuSCAT4 for the time being.

MuSCAT3 Commissioning Data

Publications that use MuSCAT3 Commissioning or Science Validation data (i.e. data acquired with the proposal ID “MuSCAT Commissioning”) must include the members of the MuSCAT3 commissioning team as co-authors. They are:

LCO: Daniel Harbeck, Mark Bowman, Mark Elphick, JD Armstrong, Jacqueline Han, Nikolaus Volgenau, Jon Nation, Elisabeth Heinrich-Josties, Steve Foale, Matt Daily, Curtis McCully, Annie Kirby, Cary Smith, Brian Haworth, Lisa Storrie-Lombardi, Patrick Conway, Joey Chatelain, Etienne Bachelet, Marshall Johnson, Markus Rabus, Fernando Rios, Sarah Rettinger, Wayne Rosing

ABC: Norio Narita, Akihiko Fukui, Tomoyasu Yamamuro, Nobuhiko Kusakabe, Taku Nishiumi, Noriharu Watanabe, Jerome de Leon, Mayuko Mori, John Livingston, Masahiro Ikoma, Motohide Tamura, Seiya Kurita, Kiyoe Kawauchi, Keisuke Isogai

Additional Information

  • The SPIE paper describing the original MuSCAT at Okayama Observatory.
  • The SPIE paper describing MuSCAT2 on the TCS at Teide Observatory.
  • The SPIE paper describing MuSCAT3 at LCO, December 2020

Please direct questions to: