jd	double	Observation Julian date at start of exposure [days]
fid	int	Filter ID (1=g; 2=r; 3=i)
pid	long	Processing ID for image
diffmaglim	[float, null], default: null	5-sigma mag limit in difference image based on PSF-fit photometry [mag]
pdiffimfilename	[string, null], default: null	filename of positive (sci minus ref) difference image
programpi	[string, null], default: null	Principal investigator attached to program ID
programid	int	Program ID: encodes either public, collab, or caltech mode
candid	long	Candidate ID from operations DB
isdiffpos	string	t or 1 => candidate is from positive (sci minus ref) subtraction; f or 0 => candidate is from negative (ref minus sci) subtraction
tblid	[long, null], default: null	Internal pipeline table extraction ID
nid	[int, null], default: null	Night ID
rcid	[int, null], default: null	Readout channel ID [00 .. 63]
field	[int, null], default: null	ZTF field ID
xpos	[float, null], default: null	x-image position of candidate [pixels]
ypos	[float, null], default: null	y-image position of candidate [pixels]
ra	double	Right Ascension of candidate; J2000 [deg]
dec	double	Declination of candidate; J2000 [deg]
magpsf	float	magnitude from PSF-fit photometry [mag]
sigmapsf	float	1-sigma uncertainty in magpsf [mag]
chipsf	[float, null], default: null	Reduced chi-square for PSF-fit
magap	[float, null], default: null	Aperture mag using 8 pixel diameter aperture [mag]
sigmagap	[float, null], default: null	1-sigma uncertainty in magap [mag]
distnr	[float, null], default: null	distance to nearest source in reference image PSF-catalog within 30 arcsec [pixels]
magnr	[float, null], default: null	magnitude of nearest source in reference image PSF-catalog within 30 arcsec [mag]
sigmagnr	[float, null], default: null	1-sigma uncertainty in magnr within 30 arcsec [mag]
chinr	[float, null], default: null	DAOPhot chi parameter of nearest source in reference image PSF-catalog within 30 arcsec
sharpnr	[float, null], default: null	DAOPhot sharp parameter of nearest source in reference image PSF-catalog within 30 arcsec
sky	[float, null], default: null	Local sky background estimate [DN]
magdiff	[float, null], default: null	Difference: magap - magpsf [mag]
fwhm	[float, null], default: null	Full Width Half Max assuming a Gaussian core, from SExtractor [pixels]
classtar	[float, null], default: null	Star/Galaxy classification score from SExtractor
mindtoedge	[float, null], default: null	Distance to nearest edge in image [pixels]
magfromlim	[float, null], default: null	Difference: diffmaglim - magap [mag]
seeratio	[float, null], default: null	Ratio: difffwhm / fwhm
aimage	[float, null], default: null	Windowed profile RMS afloat major axis from SExtractor [pixels]
bimage	[float, null], default: null	Windowed profile RMS afloat minor axis from SExtractor [pixels]
aimagerat	[float, null], default: null	Ratio: aimage / fwhm
bimagerat	[float, null], default: null	Ratio: bimage / fwhm
elong	[float, null], default: null	Ratio: aimage / bimage
nneg	[int, null], default: null	number of negative pixels in a 5 x 5 pixel stamp
nbad	[int, null], default: null	number of prior-tagged bad pixels in a 5 x 5 pixel stamp
rb	[float, null], default: null	RealBogus quality score; range is 0 to 1 where closer to 1 is more reliable
rbversion	string	version of RealBogus model/classifier used to assign rb quality score
drb	[float, null], default: null	RealBogus quality score from Deep-Learning-based classifier; range is 0 to 1 where closer to 1 is more reliable
drbversion	string	version of Deep-Learning-based classifier model used to assign RealBogus (drb) quality score
ssdistnr	[float, null], default: null	distance to nearest known solar system object; set to -999.0 if none [arcsec]
ssmagnr	[float, null], default: null	magnitude of nearest known solar system object (usually V-band from MPC archive); set to -999.0 if none [mag]
ssnamenr	[string, null], default: null	name of nearest known solar system object (from MPC archive); ‘null’ if none
sumrat	[float, null], default: null	Ratio: sum(pixels) / sum(abs(pixels)) in a 5 x 5 pixel stamp where stamp is first median-filtered to mitigate outliers
magapbig	[float, null], default: null	Aperture mag using 18 pixel diameter aperture [mag]
sigmagapbig	[float, null], default: null	1-sigma uncertainty in magapbig [mag]
ranr	double	Right Ascension of nearest source in reference image PSF-catalog; J2000 [deg]
decnr	double	Declination of nearest source in reference image PSF-catalog; J2000 [deg]
ndethist	int	Number of spatially-coincident detections falling within 1.5 arcsec going back to beginning of survey; only detections that fell on the same field and readout-channel ID where the input candidate was observed are counted. All raw detections down to a photometric S/N of ~ 3 are included.
ncovhist	int	Number of times input candidate position fell on any field and readout-channel going back to beginning of survey
jdstarthist	[double, null], default: null	Earliest Julian date of epoch corresponding to ndethist [days]
jdendhist	[double, null], default: null	Latest Julian date of epoch corresponding to ndethist [days]
scorr	[double, null], default: null	Peak-pixel signal-to-noise ratio in point source matched-filtered detection image
tooflag	[int, null], default: 0	1 => candidate is from a Target-of-Opportunity (ToO) exposure; 0 => candidate is from a non-ToO exposure
objectidps1	[long, null], default: null	Object ID of closest source from PS1 catalog; if exists within 30 arcsec
sgmag1	[float, null], default: null	g-band PSF magnitude of closest source from PS1 catalog; if exists within 30 arcsec [mag]
srmag1	[float, null], default: null	r-band PSF magnitude of closest source from PS1 catalog; if exists within 30 arcsec [mag]
simag1	[float, null], default: null	i-band PSF magnitude of closest source from PS1 catalog; if exists within 30 arcsec [mag]
szmag1	[float, null], default: null	z-band PSF magnitude of closest source from PS1 catalog; if exists within 30 arcsec [mag]
sgscore1	[float, null], default: null	Star/Galaxy score of closest source from PS1 catalog 0 <= sgscore <= 1 where closer to 1 implies higher likelihood of being a star
distpsnr1	[float, null], default: null	Distance of closest source from PS1 catalog; if exists within 30 arcsec [arcsec]
objectidps2	[long, null], default: null	Object ID of second closest source from PS1 catalog; if exists within 30 arcsec
sgmag2	[float, null], default: null	g-band PSF magnitude of second closest source from PS1 catalog; if exists within 30 arcsec [mag]
srmag2	[float, null], default: null	r-band PSF magnitude of second closest source from PS1 catalog; if exists within 30 arcsec [mag]
simag2	[float, null], default: null	i-band PSF magnitude of second closest source from PS1 catalog; if exists within 30 arcsec [mag]
szmag2	[float, null], default: null	z-band PSF magnitude of second closest source from PS1 catalog; if exists within 30 arcsec [mag]
sgscore2	[float, null], default: null	Star/Galaxy score of second closest source from PS1 catalog; if exists within 30 arcsec: 0 <= sgscore <= 1 where closer to 1 implies higher likelihood of being a star
distpsnr2	[float, null], default: null	Distance to second closest source from PS1 catalog; if exists within 30 arcsec [arcsec]
objectidps3	[long, null], default: null	Object ID of third closest source from PS1 catalog; if exists within 30 arcsec
sgmag3	[float, null], default: null	g-band PSF magnitude of third closest source from PS1 catalog; if exists within 30 arcsec [mag]
srmag3	[float, null], default: null	r-band PSF magnitude of third closest source from PS1 catalog; if exists within 30 arcsec [mag]
simag3	[float, null], default: null	i-band PSF magnitude of third closest source from PS1 catalog; if exists within 30 arcsec [mag]
szmag3	[float, null], default: null	z-band PSF magnitude of third closest source from PS1 catalog; if exists within 30 arcsec [mag]
sgscore3	[float, null], default: null	Star/Galaxy score of third closest source from PS1 catalog; if exists within 30 arcsec: 0 <= sgscore <= 1 where closer to 1 implies higher likelihood of being a star
distpsnr3	[float, null], default: null	Distance to third closest source from PS1 catalog; if exists within 30 arcsec [arcsec]
nmtchps	int	Number of source matches from PS1 catalog falling within 30 arcsec
rfid	long	Processing ID for reference image to facilitate archive retrieval
jdstartref	double	Observation Julian date of earliest exposure used to generate reference image [days]
jdendref	double	Observation Julian date of latest exposure used to generate reference image [days]
nframesref	int	Number of frames (epochal images) used to generate reference image
dsnrms	[float, null], default: null	Ratio: D/stddev(D) on event position where D = difference image
ssnrms	[float, null], default: null	Ratio: S/stddev(S) on event position where S = image of convolution: D (x) PSF(D)
dsdiff	[float, null], default: null	Difference of statistics: dsnrms - ssnrms
magzpsci	[float, null], default: null	Magnitude zero point for photometry estimates [mag]
magzpsciunc	[float, null], default: null	Magnitude zero point uncertainty (in magzpsci) [mag]
magzpscirms	[float, null], default: null	RMS (deviation from average) in all differences between instrumental photometry and matched photometric calibrators from science image processing [mag]
nmatches	int	Number of PS1 photometric calibrators used to calibrate science image from science image processing
clrcoeff	[float, null], default: null	Color coefficient from linear fit from photometric calibration of science image
clrcounc	[float, null], default: null	Color coefficient uncertainty from linear fit (corresponding to clrcoeff)
zpclrcov	[float, null], default: null	Covariance in magzpsci and clrcoeff from science image processing [mag^2]
zpmed	[float, null], default: null	Magnitude zero point from median of all differences between instrumental photometry and matched photometric calibrators from science image processing [mag]
clrmed	[float, null], default: null	Median color of all PS1 photometric calibrators used from science image processing [mag]: for filter (fid) = 1, 2, 3, PS1 color used = g-r, g-r, r-i respectively
clrrms	[float, null], default: null	RMS color (deviation from average) of all PS1 photometric calibrators used from science image processing [mag]
neargaia	[float, null], default: null	Distance to closest source from Gaia DR1 catalog irrespective of magnitude; if exists within 90 arcsec [arcsec]
neargaiabright	[float, null], default: null	Distance to closest source from Gaia DR1 catalog brighter than magnitude 14; if exists within 90 arcsec [arcsec]
maggaia	[float, null], default: null	Gaia (G-band) magnitude of closest source from Gaia DR1 catalog irrespective of magnitude; if exists within 90 arcsec [mag]
maggaiabright	[float, null], default: null	Gaia (G-band) magnitude of closest source from Gaia DR1 catalog brighter than magnitude 14; if exists within 90 arcsec [mag]
exptime	[float, null], default: null	Integration time of camera exposure [sec]
