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III/86 SKYLAB S-019 Far-UV Objective-Prism Spectrophotometry (Henize+ 1979)
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Catalog of Far-Ultraviolet Objective-Prism Spectrophotometry: Skylab Experiment
S-019, Ultraviolet Stellar Astronomy
Henize K.G., Wray J.D., Parsons S.B., Benedict G.F.
<NASA Ref. Publ. 1031 (1979)>
=1979cfuo.book.....H
=1979NASAR1031....1H
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ADC_Keywords: Spectrophotometry; Spectra, ultraviolet
Description:
The catalog contains the ultraviolet flux measurements at wavelengths
of 130-420nm, obtained with an objective-prism telescope during the
three manned Skylab missions (Skylab 2, 3 and 4) in 1973 and early
1974. The telescope is an f/3 Ritchey-Chretien system with a 15-cm
aperture and a calcium fluoride and lithium fluoride focal-plane
corrector, and a 4{deg} prism of calcium fluoride. The spectra were
obtained in 188 star fields, digitized with a PDS 1010A
microdensitometer, and each spectrum was scanned in a series of
30-micron strips. The final catalogue contains 494 spectra on 492
stars, with a resolution of 0.2mn at 140nm, 1.2nm at 200nm, and 5.2nm
at 300nm. The data on each star include the adopted fluxes, exposure
data, intermediate-band magnitudes, and cross identifications to the
Henry Draper Catalogue (Cat. <III/135>).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 252 494 Intermediate-band UV magnitudes of stars
expo.dat 47 941 List of exposures for each observed star
frames.dat 100 469 Summary of frames observed for S-019 Experiment
data.dat 5354 494 *ASCII original catalog version
sp/* . 494 Subdirectory with the 494 spectra.
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Note on data.dat:
The original ASCII version of the catalog in file data.dat.
Each record in data.dat is 5354 bytes long and contains the data for
one star. There are 494 stars, and thus, 494 records. The data are
encoded for reasons of saving space thus making access more
problematic. The files "stars.dat", "expo.dat" and files in the "sp"
subdirectory is an alternative way of getting all details about the
observed stars, their exposures, and the spectra.
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- File Name of file with spectrum, in "sp" subdirectory
14- 15 A2 --- --- [HD]
17- 22 I6 --- HD HD number (Cat. <III/135>)
24- 33 A10 --- Alt Alternative name of the star
35 A1 --- --- [(<]
36- 39 F4.2 --- r Flux adjustment factor for the star (1)
40- 42 A3 --- n_r [)>:+- ] Note about the Flux adjustment factor (1)
44 A1 --- f_m135 [UELD] Remark on m135 (G1)
45- 48 F4.2 mag m135 ?Magnitude 1347-1364{AA} (Continuum) (G3)
50- 52 F3.1 --- w_m135 ?Weight on m135 (G2)
54- 57 F4.2 mag e_m135 ?Mean error on m135
59 A1 --- f_m139 [UELD] Remark on m139 (G1)
60- 63 F4.2 mag m139 ?Magnitude 1385-1405{AA} (SiIV lines) (G3)
65- 67 F3.1 --- w_m139 ?Weight on m139 (G2)
69- 72 F4.2 mag e_m139 ?Mean error on m139
74 A1 --- f_m148 [UELD] Remark on m148 (G1)
75- 78 F4.2 mag m148 ?Magnitude 1465-1495{AA} (Continuum) (G3)
80- 82 F3.1 --- w_m148 ?Weight on m148 (G2)
84- 87 F4.2 mag e_m148 ?Mean error on m148
89 A1 --- f_m154 [UELD] Remark on m154 (G1)
90- 93 F4.2 mag m154 ?Magnitude 1521-1560{AA} (CIV + FeII + SiII
lines) (G3)
95- 97 F3.1 --- w_m154 ?Weight on m154 (G2)
99-102 F4.2 mag e_m154 ?Mean error on m154
104 A1 --- f_m161 [UELD] Remark on m161 (G1)
105-108 F4.2 mag m161 ?Magnitude 1587-1636{AA} (Temperature and gravity
sensitive blends) (G3)
110-112 F3.1 --- w_m161 ?Weight on m161 (G2)
114-117 F4.2 mag e_m161 ?Mean error on m161
119 A1 --- f_m166 [UELD] Remark on m166 (G1)
120-123 F4.2 mag m166 ?Magnitude 1636-1693{AA} (Continuum;
blends in hotter stars) (G3)
125-127 F3.1 --- w_m166 ?Weight on m166 (G2)
129-132 F4.2 mag e_m166 ?Mean error on m166
134 A1 --- f_m172 [UELD] Remark on m172 (G1)
135-138 F4.2 mag m172 ?Magnitude 1693-1760{AA} (Gravity-sensitive
blend) (G3)
140-142 F3.1 --- w_m172 ?Weight on m172 (G2)
144-147 F4.2 mag e_m172 ?Mean error on m172
149 A1 --- f_m181 [UELD] Remark on m181 (G1)
150-153 F4.2 mag m181 ?Magnitude 1770-1853{AA} (Continuum) (G3)
155-157 F3.1 --- w_m181 ?Weight on m181 (G2)
159-162 F4.2 mag e_m181 ?Mean error on m181
164 A1 --- f_m192 [UELD] Remark on m192 (G1)
165-168 F4.2 mag m192 ?Magnitude 1870-1975{AA} (Gravity-sensitive
depression (FeIII)) (G3)
170-172 F3.1 --- w_m192 ?Weight on m192 (G2)
174-177 F4.2 mag e_m192 ?Mean error on m192
179 A1 --- f_m204 [UELD] Remark on m204 (G1)
180-183 F4.2 mag m204 ?Magnitude 1975-2110{AA} (Continuum) (G3)
185-187 F3.1 --- w_m204 ?Weight on m204 (G2)
189-192 F4.2 mag e_m204 ?Mean error on m204
194 A1 --- f_m219 [UELD] Remark on m219 (G1)
195-198 F4.2 mag m219 ?Magnitude 2110-2290{AA} (Continuum;
interstellar extinction) (G3)
200-202 F3.1 --- w_m219 ?Weight on m219 (G2)
204-207 F4.2 mag e_m219 ?Mean error on m219
209 A1 --- f_m245 [UELD] Remark on m245 (G1)
210-213 F4.2 mag m245 ?Magnitude 2320-2600{AA} (Continuum;
FeII in cooler stars) (G3)
215-217 F3.1 --- w_m245 ?Weight on m245 (G2)
219-222 F4.2 mag e_m245 ?Mean error on m245
224 A1 --- f_m280 [UELD] Remark on m280 (G1)
225-228 F4.2 mag m280 ?Magnitude 2600-3070{AA} (Continuum;
MgII in cooler stars) (G3)
230-232 F3.1 --- w_m280 ?Weight on m280 (G2)
234-237 F4.2 mag e_m280 ?Mean error on m280
239 A1 --- f_m360 [UELD] Remark on m360 (G1)
240-243 F4.2 mag m360 ?Magnitude 3070-4100{AA} (Continuum;
approximate Johnson U magnitude) (G3)
245-247 F3.1 --- w_m360 ?Weight on m360 (G2)
249-252 F4.2 mag e_m360 ?Mean error on m360
--------------------------------------------------------------------------------
Note (1):
This note describes the flux adjustment factor; it is partly quoted
and partly paraphrased from the published catalogue.
The Flux adjustment factor is defined by this formula:
(absolute flux)= (S-019 flux)*r
"The absolute flux levels for most stars were compared with other
satellite measurements or with predicted fluxes to assess the accuracy
of the calibration and to provide the user with adjustment factors."
"The [flux adjustment] factor is determined by comparison at selected
wavelengths between S-019 fluxes resulting from the adopted
calibration and one of the following cases:
(a) The flux measured by the S2/68 spectrometer on the TD-1 satellite
(Jamar et al. 1976, Cat. <III/39>;
Willis and Wilson 1978MNRAS.182..559W).
(b) The flux measured by the WEP spectrometer on OAO-2 (Code and Meade
1976 Wisconsin Astrophysics preprint, see 1979ApJS...39..195C), but
adjusted by as much as 25 percent to agree with TD-1 fluxes on the
average.
(c) The flux computed from
(i) intrinsic UV colors derived from TD-1 fluxes as a function
of spectral type (Nandy et al. 1976A&A....51...63N)
(ii) the visual magnitude, and
(iii) interstellar extinction corrections using E(B-V) defined by
the Q method from UBV photometry (Johnson 1958LowOB...4...37J).
(d) The flux from model atmospheres (Kurucz et al. 1974) and from
visual magnitude."
The note n_r has the following meaning:
: Adjustment factor determined for case (c). This method is
restricted to spectral classes earlier than A0.
() Adjustment factor determined for case (d). Used for stars in
spectral classes A0 - A7 not measured by TD-1 or OAO-2.
+- Denotes a significant slope in the residual leading to a
range on the order of 0.2 to 0.3 dex from the shortest to
the longest wavelengths. A weighted mean r value is given.
<> The r value is predicted from appropriate shifts dependent on
frame number and plate position for stars for which the r value
could not be determined directly. See the printed paper,
pp. 30-31, for more details.
:: Adjustment factor determined for cases (c) and (d) when there
is uncertainty about the appropriate intrinsic colors. The
estimated color and predicted log r were averaged to obtain
the final r value presented in the catalogue.
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Byte-by-byte Description of file: expo.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [HD]
4- 9 I6 --- HD HD (Cat. III/135), as in "stars"
11- 17 A7 --- Fnum Frame number, detailed in "frames.dat" file
19- 21 I3 s ExpTime *Exposure time
22 A1 --- u_ExpTime *indicates that a default value is used.
24- 28 F5.1 mm Xpos X position of the star on the plate
30- 34 F5.1 mm Ypos Y position of the star on the plate
36- 37 I2 --- Nscan Number of microdensitometer scans of the
stellar spectrum
39- 41 F3.1 --- Weight *Weight of the spectrum
43- 46 F4.2 --- Scale *Scale value
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Note on ExpTime, u_ExpTime:
if no precise time was available, a reasonable default value is used.
Note on Weight, Scale:
see the "Note on Edata" below, relative to bytes 21-205 in file data.dat
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Byte-by-byte Description of file: frames.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Fnum *Frame number
9 A1 --- --- [(] "(" if the field center is uncertain
10- 11 I2 h RAh *? Right ascension (1950) of field center
12 A1 --- --- [:] (colon).
13- 14 I2 min RAm *? Minutes of right ascension
16- 20 F5.1 deg DEdeg *? Declination (1950) of field center
21 A1 --- u_center [)] ")" if the field center is uncertain
23- 27 A5 --- Field *Field designation.
29- 30 I2 yr Expo.Y Calendar year of exposure (offset 1900)
31- 32 I2 --- Expo.M Month of exposure
33- 34 I2 d Expo.D Day of exposure
37- 39 I3 d Expo.YD *?Day in year (1 to 365)
40 A1 --- --- [:]
41- 42 I2 h Expo.h *? UT of exposure, hours
43 A1 --- --- [:]
44- 45 I2 min Expo.m *? UT of exposure, minutes
46 A1 --- --- [:]
47- 48 I2 s Expo.s *? UT of exposure, seconds
51- 53 I3 --- CanNum Serial number of the film canister.
56- 59 F4.1 deg Tangle *? Tilt angle
62- 64 I3 deg PA *? Position angle
67- 69 I3 s Etime ?The planned, nominal exposure time
70 A1 --- Com *[UN] Blank, or comment about exposure type
72 A1 --- --- [(] "(" if the actual exposure t is uncertain
73- 75 I3 s Mtime *? Actual measured exposure time
76 A1 --- u_Mtime [)] ")" if the actual exposure t is uncertain
78-100 A23 --- rem *Remarks.
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Note on Fnum:
Frame number. Each exposure has 8 unique identifier which is referred
to in the data file (see data.dat, bytes 21-205). Each exposure
number, also called a frame number, consists of a mission number (SL2,
SL3, or SL4), and an integer exposure sequence number.
Note on RAh, RAm, DEdeg:
Field center. "The celestial orientation of Skylab was often uncertain
by 1 degree or more, so all field centers were determined with the
Becvar atlases (Becvar 1962, 1964). On the prism exposures, the highly
compressed optical end (head) of the spectrum, ending near 5000 A, was
used for positional reference." This field is blank if the frame was
for calibration or was unusable because of defects, fogging, bad
exposure, etc.
Note on Field:
Field designation. Five character designation for internal use by the
S-019 investigators (indicates the SkyLab mission number 2, 3 or 4)
Note on Expo.YD, Expo.h, Expo.m, Expo.s:
Universal Time (UT) for the start of each exposure. Bytes 37-48 are
blank for calibration exposures. "Start and end times could be
determined to the nearest second from verbal 'marks' given by the
astronaut and recorded on two-track tape, the second track containing
a time signal. (Approximately 25 percent of) this information is lost,
in which case the start time is given to the nearest minute and should
be within 2 minutes of the actual start of the observation."
Note on Tangle:
Tilt angle, which refers to the Articulated Mirror System (Henize et
al. 1979). At 0 degree tilt, the line of sight makes a 30 degree angle
with the spacecraft wall. Bytes 56-77 are blank for calibration
exposures.
Note on PA:
Position angle, defining the orientation of north on the frame. With
the print oriented so that shorter wavelengths are toward the left,
the zero point of position angle is toward the top. The angle is
measured clockwise in degrees.
Note on Com:
Blank, or the following comment character:
U = unwidened spectra
N = no prism, direct photograph
Note on Mtime:
Actual measured exposure time when determinable from the voice marks
(see bytes 37-48).
Note on rem:
Two exposures have extremely long remarks which are not included in the
machine-readable version and are as follows:
RECORD
NO. FRAME REMARK
377 SL4-050 Started before comet rise, total 253 sec
417 SL4-090 Resembles very short U expo. According to transcript,
it may have been terminated after 10 sec., <- 219.
The following are the explanations given by Heinze et al. (1979) for
abbreviations appearing in the remarks:
---------------------------------------------------------------------
REMARK MEANING
---------------------------------------------------------------------
ATM.EXT Indicates spectra are affected by atmospheric extinction.
END: Gives end time of exposure to nearest second when known,
if start time was not recorded.
(FOGGED) Indicates plate has narrow streak of fog,
or general fog greater than normal.
FOGGED Indicates plate has heavy fog, but images
may be usable.
HIFOG Indicates plate has severe fog, images not
usable.
NO IMD Indicates the spectra are trailed due to
failure to inhibit momentum dumping.
<- Indicates field was renumbered from the
pad designation.
-> Indicates this field now shared between
two adjacent fields.
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1 A1 --- n_Flux Note on flux (G1)
3- 6 I4 0.1nm lambda Wavelength
8- 15 E8.3 10mW/m2/nm Flux Absolute Flux measurement
17- 19 F3.1 --- Weight Total weight of the wavelength
21- 24 F4.1 % e_Flux Relative standard deviation
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Byte-by-byte Description of file: data.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- HD Henry Draper Catalogue (HD) number
11- 20 A10 --- alt *Alternative name of the star.
21- 205 5A37 --- Edata *Exposure data, encoded.
206 A1 --- --- First part of comment notation. Can be "("
"<", or blank. See "n_r" in bytes 211-213.
207- 210 F4.2 --- r *Flux adjustment factor r for the star
211- 213 A3 --- n_r *Note about the Flux adjustment factor
214-5213 500A10 --- Flux *Flux data, encoded.
5214-5353 14A10 --- IBmag *Intermediate-band magnitudes
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Note on alt:
Alternative name of the star. When no alternative name is given, these bytes
are the same as bytes 1-10
Note on Edata:
Exposure data. These data are contained in five fields or 37 bytes
apiece. For most stars, fewer than five exposures were used. In this
case, the exposure data fields are filled from left to right, and the
fields not used contain blanks.
21-57 A37 Edata1 - First exposure data
58-94 A37 Edata2 - Second exposure data or blank.
95-131 A37 Edata3 - Third exposure data or blank.
132-168 A37 Edata4 - Fourth exposure data or blank.
169-205 A37 Edata5 - Fifth exposure data or blank.
The exposure field format in terms of byte offsets is as follows:
+0 to +6 Plate number. Information on each frame taken throughout
the experiment can be found in the "frames.dat" file, in
the "Fnum" column.
+8 to +10 Exposure time in seconds. If no precise time was available
(because of gaps in the observing log), a reasonable default
value is used.
+11 ':' if a default value is used for the exposure
+13 to +17 X position of the star on the plate in millimeters (mm)
+19 to +23 Y position of the star on the plate in millimeters (mm)
"The plate position ... refers to the position of the optical
head of the spectrum with respect to the field center, measured
at the original plate scale. Coordinates are defined such that,
with the frame oriented (with) shorter wavelengths toward the
left, X increases toward the left and Y increases toward the
bottom. The dimensions of the 4 by 5 degrees field are 32 mm by
40 mm on this scale." NOTE: At this writing, prints of the S-019
frames can be obtained from the National Space Science Data
Center as described in the Remarks and Modifications below.
+25 to +26 Number of microdensitometer scans of the stellar spectrum.
Each scan is a longitudinal strip 30 microns (um) wide; thus
multiplying by 30 um gives the approximate width of the
spectrum. The portions that overlap with other stars are not
included.
+28 to +30 The weight of the spectrum. "The assigned weight ... for each
spectrum depends partly on the measurable width and partly on
the presumed quality of the reduction. The (Skylab mission) SL4
spectra normally receive a weight of 0.6 or 0.7, instead of
0.9 or 1.0, because the emulsion batch used was grainier and
had poorer photometric properties than the batch used on SL2
and SL3."
+32 to +35 Scale value, which is "the relative scaling of the flux values
for maximum agreement prior to averaging the different exposures.
It also was used to make an approximate adjustment when less
than the full width of the spectrum could be scanned."
Note on r, n_r:
See "Note (1)" section above (in the description of "stars.dat" file)
Note on Flux:
Each flux data is in a 10-byte field which contains all the
information in the published catalogue except the wavelength. The
wavelength is determined by the bytes in which the field appears. Note
that floating-point (F format) data have implicit decimal points.
The correspondence between wavelength and byte is determined by the
following table, in which BW is the bandwidth, MIN is the minimum of
the possible wavelengths in angstroms (A) for that bandwidth, MAX is
the maximum of the possible wavelengths in A for that bandwidth, and
BASE is the first byte of the ten-byte field corresponding to MIN. The
values MAX are redundant for determining the correspondence, but are
given for clarity. COUNT is the greatest number of fluxes that can be
given for each bandwidth; i.e., the number of ten-byte fields in that
part of the record.
Table 2-1(a). Constants for Determining Wavelength
and Bandwidth from Byte Position.
BASE
BW(A) (BYTE) MIN(A) MAX(A) COUNT
2 214 1310 1828 260
5 2814 1800 2320 105
10 3864 2300 3040 75
20 4614 3000 4180 60
The wavelengths appear in ascending order starting at the given base
bytes, each successive 10-byte field representing an increment by the
bandwidth. Thus, the following formula converts a byte number (BYTNUM)
to the corresponding wavelength (Lambda):
Lambda = ((BYTNUM-BASE)/10) *BW + MIN
The following is a description of the flux field format in
terms of byte offsets:
+0 (A1) Comment character -- see Note (G1)
+1 to +3 (I3) Digits (D) of flux measurement, as in the formula below.
+4 (I1) Order-of-magnitude code (C) of flux measurement,
as in the below formula.
Note on Flux measurement: Approximately the absolute flux
incident at the earth, averaged over the range
Lambda-BW/2 to Lambda+BW/2,
where BW has one of the values in Table 2-1(a), and where
Lambda is related to the absolute position of the field in
the record by the formula given after Table 2-1(a). This
value is given in modified exponential notation, with two
values D (digits) and C (order-of-magnitude code), such that
flux = D * 10**(-C-8) ergs cm-2 sec-1 {AA}-1
The flux is a weighted average of the data points for the
wavelength from all the exposures. Each individual weight is
a function of the slope of the characteristic curve of the
emulsion at the density of the particular wavelength (which
can vary from exposure to exposure), with the straight-line
portion weighted at 1.0.
There are eight dummy data points in the catalogue, and in
the published version these are represented by flux values
on the order of 10**(-24). These instances are are
represented by all blank flux fields in the machine-readable
version.
+5 to +6 Total weight of the wavelength. This number is calculated
from weights contributed by the individual spectra. It
refers mainly to the accuracy of the absolute fluxes, rather
than to spectral details. It also reflects the general
reliability of the data in the region, as indicated by the
comment character at offset +0. The weights of the component
spectra are described under offsets +1 to +4.
+7 to +9 Standard deviation, according to the following formula, as
a percentage of the average flux given at offsets +1 to +4:
Sig = the standard deviation
N = the number of spectra averaged
Wi = the weight of an individual spectrum as described
under offsets +1 to +4
Si = the scale factor for the exposure, given in offsets
+22 to +25 of each exposure-data field
(see bytes 21-205 above)
Fi = the flux in an individual spectrum
F = the average flux as given in offsets +1 to +4
The standard deviations "reflect both grain noise and the
effects of differences in slope among the derived energy
distributions." A long series of zero standard deviations
means that only one exposure was used in that region.
Note on IBmag:
See the "Note (G3)" below.
The intermediate-band magnitudes are in ten-byte fields of the same
form as the flux fields above, with differences which will be
explained below. The following table shows the starting byte of each
intermediate-band magnitude field:
Table 2-1b. Intermediate-Width Passbands
FIRST CENTRAL RANGE
BYTE Lambda(nm) (A) FEATURES
5214 135 1347 - 1364 Continuum.
5224 139 1385 - 1405 Si IV lines.
5234 148 1465 - 1495 Continuum.
5244 154 1521 - 1560 C IV plus Fe II plus Si II lines.
5254 161 1587 - 1636 Temperature- and gravity-sensitive blends.
5264 166 1636 - 1693 Continuum; blends in hotter stars.
5274 172 1693 - 1760 Gravity-sensitive blend.
5284 181 1770 - 1853 Continuum
5294 192 1870 - 1975 Gravity-sensitive depression (Fe III).
5304 204 1975 - 2110 Continuum.
5314 219 2110 - 2290 Continuum; interstellar extinction
5324 245 2320 - 2600 Continuum; Fe II in cooler stars.
5334 280 2600 - 3070 Continuum; Mg II in cooler stars.
5344 360 3070 - 4100 Continuum; approximate Johnson U magnitude
Following is a description of the field format of the intermediate
band magnitudes according to byte offsets.
+0 Comment character. See offset +0 under bytes 214-5213 above.
+1 to +3 Magnitude as described above, with a decimal point implicit
between offsets +1 and +2.
+5 to +6 Total weight for the passband. See offsets +5 to +6 under
bytes 214-5213 above.
+7 to +9 Standard deviation. See offsets +7 to +9 under bytes
214-5213 above. This standard deviation is to be interpreted
slightly differently from those in bytes 214-5213: this value
is "computed from the differences among the magnitudes from
separate exposures, hence the grain noise component is eliminated."
--------------------------------------------------------------------------------
Global Notes:
Note (G1): the flux comment is a blank or one of the following:
U - underexposure; the average intensity only a little above
the background fog
E - extreme exposure; the average intensity not far from saturation
L - overlapping star
D - plate defect
Note (G2): Total weight.
This number is calculated from weights contributed by the individual
spectra. It refers mainly to the accuracy of the absolute fluxes,
rather than to spectral details. It also reflects the general
reliability of the data in the region, as indicated by the flux comment
character described in the Note (G1) above.
Note (G3): UV magnitudes.
The UV magnitudes are computed over comparatively wide wavelength
intervals and are related to the fluxes by
mag =-2.5*log(F) - 21.10
where F is the average flux over the interval. The constant,
corresponding to 3.64x10^-9^ ergs.cm-2.s-1.{AA}-1 (36.4pW/nm) was
adopted in accordance with Nandy et al. (1976A&A....51...63N), "in
order to put the magnitudes on the same energy scale as visual V
magnitudes. The value of F is a straight average (rectangular
passband), except for the 360nm band, where a Johnson U filter
function is used (Mathews and Sandage 1963ApJ...138...30M). Based on
absolute calibration of U magnitudes (Johnson 1966ARA&A...4..193J),
approximately 0.20 magnitude should be subtracted to put the
ground-based U values on the same energy scale." In this magnitude
system, the width of each passband on the film is a constant 360um.
Acknowledgments:
The original ADC documentation by Robert S.Hill and Lee E. Brotzman
(1984) and the catalog by Henize et al. (1979) were used to create
this ReadMe file.
Historical Notes:
The S-019 catalogue was received from S. Parsons by the Astronomical
Data Center (ADC), NASA Goddard Flight Center, on several tapes in
1979. The treatment of the exposure data file was straightforward, and
will not be discussed here.
The spectrophotometric data was received in five files formatted for
direct dumping to a printer to produce the catalogue as originally
printed. The format has been radically changed. The data for each star
have been put into a single record. In order to shorten the records to
the degree possible, the flux data format has been condensed, mostly
through the implicit representation of wavelength by the location of
each datum in the record. No data have been changed or edited in
regard to their content. The format was designed in order to simplify
the structure of any Fortran program that would use the data by making
it possible for one Fortran READ statement to store in variables all
of the required data for any given star. Prints of the S-019 fields
can be obtained from the National Space Science Data Center, NASA
Goddard Space Flight Center, Greenbelt, MD 20771.
* 24-Sep-2001: FITS files corrected at ADC.
* 25-Jan-2002: the file "stars.dat" and the ascii version of the spectra
were generated at CDS -- one spectrum of beta Lyr (174638) was missing;
the description was also reformulated.
References:
Becvar, A. 1962 and 1964, "Atlas Borealis, Atlas Eclipticalis, Atlas
Australis", Czech. Acad. of Sci., Praha, and Sky Publ. Co., Cambridge,
Mass.
Code, A.D., and Meade, M.R. 1976, "Ultroviolet Photometry from the Orbiting
Astronomy Observatory, An Atlas of Ultraviolet Stellar Spectra",
Wisconsin Astrophysics (preprint), 30, 101pp; see 1979ApJS...39..195C
Jamar C., Macau-Hercot, Monfils, Thompson, Houziaux, and Wilson, 1976,
"Ultraviolet bright-star spectrophotometric catalogue.
A compilation of absolute spectrophotometric data obtained with the sky
survey Telescope (S2/68) on the European Astronomical Satellite TD-1",
European Space Agency SR-27, 489pp (see Cat. <III/39>)
Johnson, H.L. 1966, Ann. Rev. Astr. Astrphys. 4, 193 (1966ARA&A...4..193J)
Johnson, H.L. 1958, Lowell Obs. Bull., 4, 37 (1958LowOB...4...37J)
Kurucz, R.L., Peytremann, E., and Avrett, E.H. 1974, "Blanketed Model
Atmospheres for Early-Type Stars, Smithsonian Institution Press
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(End) Paul Kuin and C.-H. Joseph Lyu [Hughes STX/NASA ADC] 29-Jan-1997