Hyper Suprime-Cam (HSC)

Information for S20B applicants:

There will be at most 5 observing runs of HSC from September to January in S20B.

HSC queue mode is opened for the Normal, Intensive, and Filler programs as the primary mode of HSC observations. Applicants wishing a classical mode observation have to clarify the reason why the classical mode is preferred to the queue mode. See the detail information at the "HSC Queue Mode Webpage". Note that a proposal requesting the NB387 filter must be submitted as a classical mode program.

Applicants requesting to observe the same fields as targeted in the HSC Subaru Strategic Program (SSP) are obliged to clarify the reason for doing so (e.g., how the scientific aim is different from that of SSP). One can find its survey fields at the web page of HSC SSP.

Requesting additional targets for filling dead time ("Sukima" time), when there is no planned target on the night sky, in the classical mode programs is NOT allowed. "Sukima" time will be exploited as effectively as possible depending on the situation (observing priority: 1. observations of standard stars, 2. queue-mode observations for Grade A/B programs, 3. observing user's back-up targets listed in the proposal, and 4. queue-mode observations for Grade C or Filler programs).

The NB497 filter is newly opened from S20B. If you are interested in using narrow-band filters, you may need to obtain an approval in advance from the filter developer team. See "Available filters and sensitivities" for detailed information and the contact addresses.

The filter exchanger unit (FEU) can hold up to 6 filters. It is possible to change the filter set of one (optical-side) filter stacker storing three filters in daytime while an HSC observing run is ongoing. At this moment, this operation will be limited to once in an observing run at a maximum. In addition, the number of available NB filters in a night is still limited to one because the HSC SSP uses five broad-band filters ( g, r2, i2, z, and Y ) in each observing run.

HSC applicants must explicitly describe the filters they intend to use in "Instrument Requirements" section of the application form, where the desired set as well as the minimum acceptable set should be clearly specified.

Last update: January 22, 2020

Advice for observers of HSC S19A/S19B programs:

  It was confirmed that HSC images had suffered from two kinds of problems since late February 2019.
  Please be sure to read the following announcements for reduction of HSC data obtained in the corresponding periods.
  1.   Shadow due to a lens stain   ( 2019/2/27–10/4 UT )

  2.   Arc-shaped ghost due to stray light from the dome inside   ( 2019/2/27–11/6 UT )

Last update: November 15, 2019



The Hyper Suprime-Cam (HSC) is a gigantic mosaic CCD camera, which is attached at the prime focus of Subaru Telescope. The HSC uses 104 main science CCDs, which covers 1.5-deg field-of-view in diameter with a pixel scale of 0.17 arcseconds, as well as 4 CCDs for auto guider, and 8 CCDs for focus monitoring.

It takes about 30 min for changing filters (including a focus check). When we exchange filters, it is necessary for us to move telescope to the zenith position, and rotate the instrument rotator to the appropriate angle. we also close the cover of the primary mirror for safety operation.

When you cosider to produce new HSC filters, please read the filter policy carefully, and contact Subaru Telescope (new development group: newdev_at_naoj.org) well before applying for funds. Also, please refer the procedure to determine filters for each HSC run.

We ask for your understanding in advance that observed data, whose proprietary periods (1.5 yrs) do not end, may be used by Subaru staff without PI's permission for engineering purposes.



Data Analysis


Image Quality

Problem Reports


Questions regarding HSC should be directed to Dr. Satoshi Miyazaki (satoshi_at_naoj.org), Dr. Fumiaki Nakata (nakata_at_naoj.org) and/or Tsuyoshi Terai (terai_at_naoj.org).

Please note that all numbers on these pages are subject to change as the performance of HSC is better determined.

Last update: April 6, 2020

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