IUELOG - IUE (International Ultraviolet Explorer) Final Merged Observation Log
Final Merged Log of IUE Observations NASA / ESA / SERC <IUE Newsletters (1978-2000)>
The name of the IUE Camera used for the observation:
LWP = Long Wavelength Prime Camera (Camera no.1) LWR = Long Wavelength Redundant Camera (Camera no.2) SWP = Short Wavelength Prime Camera (Camera no.3) SWR = Short Wavelength Redundant Camera (Camera no.4)
The IUE Image Number of the observation. Together with the camera used, this usually is enough to uniquely specify an observation: in a small number of cases, where both large and small apertures were used, this latter parameter value is required in addition to provide a unique specification.
The dispersion mode of the observation, where H stands for High, L for Low, and N for "Not Applicable".
The aperture used for the observation, where L stands for the Large (10 by 20 arcsecond oval) aperture, S for the Small (3 arcsecond circular) aperture, and N for "Not Applicable".
The date and time of the start of the observation in UT.
The exposure mode of the observation, consisting of 3 characters with the following meaning:
First Character (multiple exposures in the large aperture): N No multiple exposures made (most common case) A Multiple exposures along the APERTURE X X-offsets along FES X-axis for multiple exposures Y Y-offsets along FES X-axis for multiple exposures O Other configuration for multiple exposures Middle character (segmented exposure) N No, exposure taken by one commanded exposure (most common case) Y Yes, exposure was segmented Last character (trailed exposure) N No trail (most common case) X Exposure trailed along FES X-axis Y Exposure trailed along FES Y-axis
The extraction mode for the observation, where P stands for Point, E for Extended source extraction.
The effective exposure time, in seconds
The heliocentric-corrected Julian Date corresponding to the mid-exposure of the observation.
The Homogeneous Object Identifier of the target: this is essentially the IUE-standard name of the object, based on a prioritized set of catalogs, e.g., for a star, if it is in the Henry Draper (HD) Catalog, it will be the HD name.
The Right Ascension of the IUE pointing for the observation in the specified equinox. Together with the Dec parameter, these two parameters comprise the homogeneous IUE coordinates for the observation. Particularly for extended objects, the homogeneous coordinates may differ from the targets as given by the IUE Guest Observer (GO) (which are contained in the ra_target and dec_target parameters). In the originating table, the RA parameter was given in J2000 equinox decimal degrees and with a precision of 0.0001 degrees.
The Declination of the IUE pointing for the observation in the specified equinox. Together with the RA parameter, these two parameters comprise the homogeneous IUE coordinates for the observation. Particularly for extended objects, the homogeneous coordinates may differ from the targets as given by the IUE Guest Observer (GO) (which are contained in the ra_target and dec_target parameters). In the originating table, the Dec parameter was given in J2000 equinox decimal degrees and with a precision of 0.0001 degrees.
The Galactic Longitude of the IUE pointing for the observation.
The Galactic Latitude of the IUE pointing for the observation.
The Position Angle of the Large Aperture for the observation, in degrees.
The Fine Error Sensor (FES) mode (this is needed to convert FES counts into a visual magnitude):
FU = Fast track/Underlap FO = Fast track/Overlap SO = Slow track/Overlap SU = Slow track/Underlap (HEASARC guess) BO = ? (not mentioned in CDS documentation)
The Fine Error Sensor (FES) counts of the target (contaminated after Nov. 1991): this can be used together with the FES mode to estimate the visual magnitude of the target. The FES counts are photon counts averaged over an integration time that is dependent on the needs of the specific target acquisition. Notice that the FES detector saturates at a count level of 28673!
The target name as given by the Guest Observer (GO).
The Right Ascension (J2000) of the target as given by GO, which may differ from the homogeneous IUE coordinates, e.g. for extended objects.
The Declination (J2000) of the target as given by GO, which may differ from the homogeneous IUE coordinates, e.g. for extended objects.
The IUE Object Class, according to the following schema:
00 Sun 50 R, N or S types 01 Earth 51 Long Period Variable Stars 02 Moon 52 Irregular Variables 03 Planet 53 Regular Variables 04 Planetary satellite 54 Dwarf Novae 05 Minor Planet 55 Classical Novae 06 Comet 56 Supernovae 07 Interplanetary medium 57 Symbiotic Stars 08 Giant Red Spot 58 T Tauri 59 X-Ray Source 10 WC 60 Shell Star 11 WN 61 Eta Carinae 12 Main Sequence O 62 Pulsar 13 Supergiant O 63 Nova-like 14 Oe 64 Other stellar Object 15 Of 65 Misidentified targets 16 sdO 66 Interacting Binaries 17 WD O 19 UV-strong 69 Herbig-Haro Object 20 B0-B2 V-IV 70 Planetary Nebula + Central Star 21 B3-B5 V-IV 71 Planetary Nebula - Central Star 22 B6-B9,5 V-IV 72 H II Region 23 B0-B2 III-I 73 Reflection Nebula 24 B3-B5 III-I 74 Dark Cloud (absorption spectrum) 25 B6-B9.5 III-I 75 Supernova Remnant 26 Be 76 Ring Nebula (shock-ionised) 27 Bp 28 sdB 29 WDB 30 A0-A3 V-IV 80 Spiral Galaxy 31 A4-A9 V-IV 81 Elliptical Galaxy 32 A0-A3 III-I 82 Irregular Galaxy 33 A4-A9 III-I 83 Globular Cluster 34 Ae 84 Seyfert Galaxy 35 Am 85 Quasar 36 Ap 86 Radio Galaxy 37 WDA 87 BL Lacertae object 38 Horizontal Branch 88 Emission Line Galaxy (non-Seyfert) 39 Composite 40 F0-F2 90 Intergalactic Medium 41 F3-F9 42 Fp 43 Late Type Degenerate Stars 44 G IV-VI 45 G I-III 46 K IV-VI 47 K I-III 48 M Dwarfs 98 Wavelength Calibration Lamp 49 M I-III 99 Nulls and Flat FieldsThere is also one object in this catalog with an iue_class of 67 which appears to be a Herbig-Haro Object, and two objects with iue_class values of 95, the meaning of which is not stated in the CDS documentation.
The IUE Exposure Classification Code, made up of 3 characters with meaning according to the following scheme:
Left Character (exposure levels of continuum) Middle Character (exposure levels of emission line) both are coded as following: 0 = Not applicable 1 = No spectrum visible 2 = Faint spectrum: max dn < 20 above local background 3 = Underexposed: max dn < 100 above local background 4 = Weak: 100 < max dn < 150 above local background 5 = Good: no sat., max dn > 150 above local background 6 = a bit strong: a few pixels are saturated 7 = saturated for less than half the spectrum 8 = mostly saturated but some parts usable 9 = completely saturated Right Character (background level). This is classified in terms of a standard region of each camera outside the area affected by the high resolution orders. The value used is the mean dn given by a subset histogram approximately 10 pixels in width: 0 = 0 < dn < 20 1 = 21 < dn < 30 2 = 31 < dn < 40 3 = 41 < dn < 50 4 = 51 < dn < 60 5 = 61 < dn < 70 6 = 71 < dn < 80 7 = 81 < dn < 90 8 = 91 < dn < 100 9 = 101 < dn < ... X = saturated
Notice: In the CDS documentation, the meaning of both the first and second characters of this parameter was stated to be the coded exposure level of the continuum: it appears to the HEASARC that this is a typographical error and that the second character refers to the exposure level of (usually the strongest intrinsic) emission line in the spectrum. Also, "dn" is the IUE data number, which has 256 possible values from 0 to 255.
The identification code for the IUE Observing Program under which the target was observed.
The observing station for the observation, where G means Goddard Space Flight Center (GSFC) and V stands for the European VILSPA station.
The Abnormality Codes for the observation, according to the following scheme:
A = Abnormal READ (ABNREAD) B = BAD Scans LWP (ABNBADSC) C = CORRUPTION including 159 DN H = History Play back (ABNHISTR) M = Missing THDA, any of THDAEND, THDAREAD, or THDASTRT N = Non-standard image acquisition ABNNOSTD O = OFFSET from nucleus; from center; etc. P = Readmode = PARTIAL R = REMNANT of previous spectrum visible S = Serendipity Exposure T = TRACK LOST U = UVC voltage other than -5Kev W = ABNHTRWU = LWR Heater Warm Up Z = contamination by solar spectrum or extended source 8 = Cross-correlation less than 80% - CC-PERCN
The HEASARC Browse object classification, constructed from the IUE_class parameter. Notice that the correspondence between these tow classification schemes is only approximate, and that the IUE_class is probably more accurate.