Filter ID (?) :	Swift/UVOT.B
Description (?) :	UVOT B filter effective area
Phot.System (?) :	UVOT
Detector Type (?) :	Photon counter
Band Name (?) :	B
Obs. Facility (?) :	Swift
Instrument (?) :	UVOT
Comments (?) :	Take into account that there is a time-dependent, and filter-dependent decline in sensitivity for the UVOT (which reaches as much as ~30% in UVW2) since launch, and that the filter effective areas provided reflect the case at approximately mission start, so any computation of expected output in the UVOT at a given epoch after mission start, should take these degradation factors into account. The current document describing the degradation is available at https://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/swift/docs/uvot/

Property	Calculated	Specified	Unit
λref (?) :	4349.56	-------	(Angstrom)
λmean (?) :	4377.97	-------	(Angstrom)
λcen (?) :	4379.85	-------	(Angstrom)
λeff (?) :	4346.25	-------	(Angstrom)
λpeak (?) :	4282.49	-------	(Angstrom)
λpivot (?) :	4349.56	-------	(Angstrom)
λphot (?) :	4363.94	-------	(Angstrom)
λmin (?) :	3702.38	-------	(Angstrom)
λmax (?) :	4995.23	-------	(Angstrom)
Weff (?) :	866.22	-------	(Angstrom)
FWHM (?) :	978.33	-------	(Angstrom)
Af/AV (?) :	1.32	-------	()
Fsun (?) :	177.83	-------	(erg/cm2/s/A)

Data file: ascii, VOTable

Reference for filter response: HEASARC CALDB

Transmission components: Filter + Instrument

Vega System

Property	Specified	Calculated	Unit
Zero Point (?) :	-------	6.44317e-9	(erg/cm2/s/A)
	-------	4059.84	(Jy)
ZP Type (?) :	Pogson
PhotCal ID (?) :	Swift/UVOT.B/Vega

AB System

Property	Specified	Calculated	Unit
Zero Point (?) :	-------	5.76258e-9	(erg/cm2/s/A)
	-------	3631.00	(Jy)
ZP Type (?) :	Pogson
PhotCal ID (?) :	Swift/UVOT.B/AB

ST System

Property	Specified	Calculated	Unit
Zero Point (?) :	-------	3.631e-9	(erg/cm2/s/A)
	-------	2287.89	(Jy)
ZP Type (?) :	Pogson
PhotCal ID (?) :	Swift/UVOT.B/ST