Data Naming Convention
NOTE: A suffix _xx below denotes the object identification, where xx = T1, C1, T2,
C2, T3, C3, …
Saturated – zero indicates that the peak value
of the target and all comparison stars is less than the value set in the “Set_Apertures” module. A number other than zero indicates
that highest peak value that exceeded the set limit.
J.D.-2400000 – Julian Day of the observation (UTC
based). Availability requires UTC time-of-day information in the FITS header of
the observed data.
JD_MOBS – Julian Day of the mid-point of the
exposure for this observation (UTC-based). This value is inserted into the FITS
header by the Data Processor module when the “FITS Header Updates” option is
enabled and target coordinates and observatory geographic location are
provided. In addition, UTC time-of-day and exposure time information are
required to exist in the FITS header of the observed data.
HJD_MOBS – Heliocentric Julian Day of the
mid-point of the exposure for this observation (UTC-based). This value is inserted
into the FITS header by the Data Processor module when the “FITS Header
Updates” option is enabled and the target coordinates and observatory
geographic location are provided. In addition, UTC time-of-day and exposure
time information are required to exist in the FITS header of the observed data.
BJD_MOBS – Barycentric Julian Day of the
mid-point of the exposure for this observation (BJDTDB-based). This value is inserted into
the FITS header by the Data Processor module when the “FITS Header Updates”
option is enabled and the target coordinates and observatory geographic
location are provided. In addition, UTC time-of-day and exposure time
information are required to exist in the FITS header of the observed data.
ALT_OBJ – altitude above the horizon of the
target object at mid-exposure. This value is inserted into the FITS header by
the Data Processor module when the “FITS Header Updates” option is enabled and
the target coordinates and observatory geographic location are provided. In
addition, UTC time-of-day and exposure time information are required to exist
in the FITS header of the observed data.
AIRMASS – airmass of the target object at
mid-exposure. This value is inserted into the FITS header by the Data Processor
module when the “FITS Header Updates” option is enabled and the target
coordinates and observatory geographic location are provided. In addition, UTC
time-of-day and exposure time information are required to exist in the FITS
header of the observed data.
Source_Radius
– radius of the aperture
used to calculate total integrated counts. In fixed aperture mode, this value is
the aperture radius set by the user. When the variable aperture mode is used,
this value represents the actual aperture radius used considering the object’s full
width half maximum (FWHM). In variable aperture mode, Source_Radius
= (Width_x1) * (FWHM_Mult).
FWHM_mult
– the FWHM multiplier
value set by the user in variable aperture mode. In variable aperture mode, Source_Radius = (Width_x1) * (FWHM_Mult).
In fixed aperture mode, this column is not included in the table.
Source_Rad(base) – in variable aperture mode, this
value represents the fixed aperture radius set by the user to measure the FWHM.
This value should be set to a number greater than 1.5 times the maximum FWHM
expected. In fixed aperture mode, this column is not included in the table.
Sky_Rad(min) – radius of the inner edge of the
annulus used to calculate the sky background
Sky_Rad(max) – radius of the outer edge of the
annulus used to calculate the sky background
X(IJ)_xx
– x-location in
ImageJ coordinates of the center of the aperture located at object xx
Y(IJ)_xx
– y-location in
ImageJ coordinates of the center of the aperture located at object xx
X(FITS)_xx
– x-location in FITS
coordinates of the center of the aperture located at object xx
Y(FITS)_xx
– y-location in FITS
coordinates of the center of the aperture located at object xx
rel_flux_Tx – the ratio of target Tx’s net integrated counts to the
total of all comparison star net integrated counts. Mathematically the value is
Source-Sky_Tx / SumOfAll(Source-Sky_Cx )
rel_flux_Cx – the ratio of the comparison star Cx’s net integrated counts to the total of all OTHER
comparison star net integrated counts. This value requires at least two
comparison stars be selected. Mathematically the value is Source-Sky_Cn / (SumOfAll(Source-Sky_Cx)), where x not
equal n. For clarification, target star net integrated counts are not used for
these calculations.
rel_flux_err_xx – the error in the relative flux for
object xx. The error is calculated by propagating all Source_Error_xx
values through the equations defined for rel_flux_xx above.
rel_flux_SNR_xx – signal-to-noise ratio for rel_flux_xx. This value is simply rel_flux_xx
/ rel_flux_err_xx.
Source-Sky_xx
– net integrated
counts within the aperture located at object xx. Net
integrated counts is defined as the sum of all pixels whose center falls
within the aperture source radius, less the sky background per pixel. Sky
background is either the average value of the pixels in the annulus defined by Sky_Radius(min)
and Sky_Radius(max), or the value from a plane fitted
to the values in the sky annulus. The user can select which method to use for
calculation of sky background in the “Set_Aperture”
module.
Source_Error_xx –
error in Source-Sky_xx. The calculation includes
contributions from read-out-noise, dark current, and source and sky poisson noise as defined by Merline,
W. & Howell, S.B., 1995, EXP. ASTRON., 6, 163. The equation is:
SourceError = SquareRoot ((NetSourceCounts * gain +SourcePixelCount
* (1 + SourcePixelCount / SkyPixelCount)
* (TotalSkyCounts * CCDgain
+ DarkNoisePerPixel + ReadOutNoisePerPixel
* ReadOutNoisePerPixel + CCDgain
* CCDgain * 0.289)) / CCDgain)
Source_SNR_xx –
signal-to-noise ratio for Source-Sky_xx. This value is simply Source-Sky_xx / Source_Error_xx.
tot_C_cnts – the sum of all comparison star net
integrated counts. tot_C_cnts = Source-Sky_C2 +
Source-Sky_C3 + …
tot_C_err – the error in tot_C_cnts.
The error is calculated by combining Source_Error_C2 + Source_Error_C3 + … in quadrature.
Peak_xx
– the highest pixel
value within the aperture for object xx (NOT background subtracted)
Mean_xx
– the mean pixel value
within the aperture for object xx (NOT background subtracted)
Sky/Pixel_xx
– the mean pixel
value within the sky-background annulus for object xx
X-Width_xx – the X-direction FWHM of the PSF of
object xx. The aperture radius must extend beyond the object’s PSF for this
number to be accurate.
Y-Width_xx – the Y-direction FWHM of the PSF of
object xx. The aperture radius must extend beyond the object’s PSF for this
number to be accurate.
Width_xx –
the mean of the X- and Y-direction FWHM of object xx. The aperture radius must extend
beyond the object’s PSF for this number to be accurate.