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This table records high-level information for the observations obtained with NICER (Neutron star Interior Composition ExploreR) and provides access to the NICER data archive. NICER is a NASA Explorer program Mission of Opportunity dedicated to the study of the neutron stars, exploring the exotic states of matter where density and pressure are higher than in atomic nuclei. NICER instrument is a payload aboard the International Space Station (ISS). It was launched on 3 June 2017 on a SpaceX Falcon 9 rocket and placed on the ISS. Normal operation started on 17 July 2017 after a commission phase to test the system and perform initial calibration.

NICER's X-ray Timing Instrument (XTI) consists of an aligned collection of 56 X-ray "concentrator" optics (XRC) and silicon drift detector (SDD) pairs working in the energy range of 0.2-12 keV. Each XRC collects X-rays over a large geometric area from a roughly 30 arcmin2 region of the sky and focuses them onto a small SDD. The SDD detects individual photons, recording both energies (with a 3% energy resolution at 6 keV) and high precision times (with 100 nanoseconds RMS relative to Universal Time).

During one day of operation, NICER monitors several sources. For each observed source the data are divided into intervals of one day and labeled with a sequence number. This database table contains one record for each sequence number and includes parameters related to the observation.


The NICERMASTR database table was last updated on 20 March 2019.


The Neutron star Interior Composition ExploreR (NICER): Design and Development:
    Gendreau, K.C., Arzoumanian, Z. et al. 2016, Proc. SPIE 9905,
    Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray,
    99051H (22 July 2016)


This contents of this database table are generated at the NICER Science and Mission Operations Center (SMOC) and updated regularly with new observations.


This is the designation of the pointed target.

Right Ascension of the pointing position. Note that the pointing position can be different from the target position.

Declination of the pointing position. Note that the pointing position can be different from the target position.

Galactic Longitude of the pointing position. Note that the pointing position can be different from the target position.

Galactic Latitude of the pointing position. Note that the pointing position can be different from the target position.

The start time of the observation.

The time corresponding to the end of the observation.

The unique number to identify an observation/sequence. This is a 10-digit number.

The effective total observation exposure, in seconds.

The time awarded for this target, in seconds. The value of zero is assigned to all observations that are not part of the Guest Observer program.

The number of Focal Plain Modules (FPM) after the data screening.

This records the status of the processing of the data from the observation. The strings are VALIDATED, PROCESSED, or NOTPROCESSED. If the string is VALIDATED implies that the data are located in the archive. If the string is PROCESSED implies that the data have been processed but not validated yet. If the string is NOTPROCESSED implies that the data have not been processed.

This parameter records the date when the data were last processed.

This is the date when the data became public.

This records the version of the processing script used in the pipeline to generate the data products for the observation.

This records the number of times a data set has been processed.

This records the version of the NICER CALDB version. This is encoded as genYYYYMMDD_xtiYYYYMMDD, such that YYYYMMDD represents the date of the index file.

This records the version of the HEAsoft and NICER software used in the processing pipeline to generate the data products of the observation.

This number uniquely identifies the proposal that originated the observation.

This parameter contains a short description of the aim of the observation.

The subject category is a string that identifies the type of object observed by NICER and associated to this sequence number. These strings have the following meanings:

       BURST     : Observations of X-ray burst sources
       CAL       : Calibration observations
       DIR       : Director's discretionary time
       ENG       : Engineering data (generally non-science)
       LCM       : Observations of pulsar lightcurves (useful for modeling)
       MAGNETAR  : Observations of magnetars
       OSWG      : Observatory Science Working Group observations
       SEARCH    : X-ray pulse search targets
       TIMING    : Pulsar observations having to do with calibration of
                     absolute timing

Each subject category is assigned a numerical code, and this field contains that numerical value for the specified subject category.

The last name of the proposal's Principal Investigator.

The first name of the proposal's Principal Investigator.

The cycle number of the proposal. The value of 0 is used for the check-out phase, corresponding to the first observing month.

The type of observation. Possible values and their respective meanings: NOR for a normal observation, CAL for a calibration observation, and DDT for discretionary director time. The values NOR-TOO, CAL-TOO, and DDT-TOO are assigned if the observation is also a target of opportunity.

The title of the proposal that originated the observation.

Additional remarks concerning the observation.

Contact Person

Questions regarding the NICERMASTR database table can be addressed to the HEASARC User Hotline.
Page Author: Browse Software Development Team
Last Modified: Monday, 10-Sep-2018 18:19:51 EDT