Fourth Catalog of Interferometric Measurements of Binary Stars: Format
The entries for each binary star system are comprised of two parts: an identification
line containing designations from various catalogs, followed by individual measures
sorted in order of observation date. Formats of these data are as follows:
Identification line:
Column Format Description
1 t1,a18 Epoch-2000 coordinates, to 0.1s in RA, 1" in DEC when known
(HHMMSS.SS+DDMMSS.S)
2 t21,a26 Star name #1 (usually ADS or HR number, otherwise DM or
other catalog designation)
3 t47,a26 Star name #2 (discoverer designation, Bayer, Flamsteed, or
variable star name, GJ number, or other catalog designation)
4 t73,a13 HD or DM number. Formats are 'HD 123456', 'BD+12 1234',
'CD-1212345', or 'CP-1212345'
5 t86,a3,1x,a15 Hipparcos, SAO, Tycho-2, GSC, or other designation. The first
three characters indicate the catalog (G22 = GSC2.2, UC2 = UCAC2,
etc.)
6 t105,a10 WDS designation or epoch-2000 coordinates in the form of the
WDS designation (HHMMM+DDMM)
7 t116,a1 General flag:
I - uncertainty in catalog match for precise coordinates in
column 1
N - note about object in notes file
8 t118,a1 Orbit flag. Pair has a published visual or astrometric orbit
in the Sixth Orbit Catalog.
Data lines:
Column Format Description
1 t2,a1 Epoch flag:
: - epoch not given in paper; the date is estimated based on
comments in the text.
< - no information on epoch in text. An upper limit to the date
is given, based on the date of publication.
2 t3,f9.4 Epoch of observation, given as fraction of the Besselian year
(even though they may have been given in some other form in the
original reference). The number of significant digits in the
epoch reflects the accuracy in the time as quoted in the original
source.
3 t14,a1 Position angle flag:
V - position angle is vector angle of a one-dimensional (e.g.
occultation) measure
: - measure of lower accuracy
? - questionable position angle value
4 t15,f7.3 Position angle in degrees. Position angles have occasionally been
adjusted to their "proper" quadrant; it should be remembered that
interferometry often yields position angle determinations with a
180-degree ambiguity.
5 t23,a1 Position angle error flag:
< - quoted error is upper limit
> - quoted error is lower limit
Note: A very small number of measures give errors of 10 degrees
or more; hence a "1" or "2" in this column
6 t24,f5.3 Position angle error (if given in the original reference).
7 t29,a1 Separation flag:
< - value given is the upper limit for an unresolved measure
(usually the Rayleigh limit, a function of the telescope
aperture and filter)
> - value given is a lower limit of the true separation
: - measure is of lower accuracy
? - questionable measure or flag for possible duplicity
D - separation is in degrees
e - pair is elongated (along direction of position angle, if
given)
m - separation is in milliarcseconds
M - separation is in arcminutes
R - pair is noted as being resolved, but no separation is given
U - pair is unresolved, but no resolution limit is given
Hipparcos non-component double star solutions and suspected
non-single stars are indicated by the following codes:
G - Hipparcos non-component double star solution
(acceleration solution)
O - Hipparcos non-component double star solution
(orbit solution)
S - Hipparcos suspected non-single
V - Hipparcos non-component double star solution
(variability-induced mover)
X - Hipparcos non-component double star solution
(stochastic solution)
8 t30,f10.6 Separation in arcseconds. For one-dimensional measures this value
is the vector, rather than true separation.
9 t41,a1 Separation error flag:
V - published qualitative rating of very poor
P - published qualitative rating of poor
F - published qualitative rating of fair
G - published qualitative rating of good
< - quoted error is an upper limit
> - quoted error is a lower limit
Note: occasionally a paper will quote a range in separation over
which an object is unresolved. In this case (and if the upper limit
is less than 10") columns 7 and 8 will indicate the lower limit of
the separation range, while columns 9 and 10 will indicate the
upper limit, with a ">" flag in column 9.
10 t42,f8.6 Separation error (if given in the original reference).
11 t51,a1 Primary magnitude flag.
: - uncertain magnitude estimate
> - primary is fainter than indicated magnitude
t - value listed is combined magnitude of pair
v - primary is variable in magnitude
12 t52,f6.3 Primary magnitude.
13 t59,a1 Primary magnitude error flag:
< - error is less than indicated value
14 t60,f5.3 Primary magnitude error.
15 t66,a1 Secondary magnitude flag:
: - uncertain magnitude estimate
< - secondary is brighter than indicated magnitude
> - secondary is fainter than indicated magnitude
q - author does not gives magnitude information, but notes
that reduction technique used (e.g., triple correlation)
yields unambiguous quadrant determination
s - magnitude is of secondary despite column 12 being blank
v - secondary is variable in magnitude
16 t67,f6.3 Secondary magnitude or, if column 12 is blank, magnitude difference
17 t74,a1 Secondary magnitude error flag:
< - error is less than indicated value
18 t75,f5.3 Secondary magnitude or magnitude difference error.
19 t83,f4.0 Filter effective wavelength (in nanometers unless otherwise noted)
20 t87,f4.0 Filter FWHM (in nanometers unless otherwise noted)
21 t91,a1 Filter flag:
a - average of two or more different filters. Filter columns now
indicate mean wavelength and sigma of the filters averaged.
c - filter effective wavelength and FWHM are in centimeters
m - filter effective wavelength and FWHM are in millimeters
M - filter effective wavelength and FWHM are in meters
n - no filter used in observation
u - filter effective wavelength and FWHM are in microns
x - x-ray band
? - filter information is uncertain
22 t93,f4.1,a1 Telescope aperture or baseline of multiple-aperture array
(in meters, unless noted)
23 t97,a1 Telescope aperture code:
k - long-baseline interferometer, baseline in kilometers
24 t99,i2 "Number of nights". Occasionally published measures are averages
of more than one observation. This practice was more common in
earlier publications; the inclusion of data obtained by eyepiece
interferometry prompted the inclusion of this column. Relative
weighting of measures is typically scaled by the square root of
this value.
25 t103,a8 Code for the original reference. Code format is the WDS
Discoverer Designation code (usually the first three letters of
the first author's name), followed by the publication year. An
"a", "b", ... follow if necessary to differentiate publications
by more prolific authors. The list of references is given here.
26 t112,a3 Technique code. Codes are based (as closely as possible) on those
used in the WDS. The first letter of each code corresponds to the
WDS code; the second and third characters break these codes down
into a little more detail (for example, the specific long-baseline
interferometer or HST instrument). Codes are as follows:
E = Wide-field CCD or other 2-dimensional electronic imaging
E2m = 2MASS (Two Micron All-Sky Survey)
Ech = Chandra
Ede = DENIS (Deep Near-Infrared Survey)
Eei = Einstein
Esd = SDSS (Sloan Digital Sky Survey)
Eu3 = UCAC3
Eu4 = UCAC4
Euk = UKIDSS (UKIRT Infrared Deep Sky Survey)
F = CCD or other two-dimensional electronic imaging
Fic = IR coronagraph
Fip = IR imaging polarimetry
Fir = IR direct imaging
Fss = IR one-dimensional slit scanning
Fsi = short-exposure CCD imaging, keeping only selected images
("lucky imaging")
G = photographic, with astrograph
Gac = Astrographic Catalog
Gag = AGK Catalog
Gp1 = Palomar Observatory Sky Survey (POSS-I)
1948-1958, 48in/1.2m Schmidt
Gp2 = Palomar Observatory Sky Survey (POSS-II)
1985-1999, 48in/1.2m Schmidt
Guk = UK Schmidt Southern Survey
1974-1987, 48in/1.2m Schmidt
J = visual interferometer
Jmw = Mount Wilson 100-inch telescope interferometer
(Anderson, Merrill)
Jpe = Mount Wilson 20-foot beam interferometer (Pease)
K = long-baseline visual/IR/radio interferometer
Kap = radio/IR aperture synthesis technique
Kbi = BIMA
Kce = CERGA 2-telescope interferometer
Kch = CHARA Array
Kcs = CHARA Array (separated fringe packet data)
Kev = European VLBI network
Km3 = Mark III
Kio = IOTA
Kki = Keck interferometer
Knp = NPOI (Navy Prototype Optical Interferometer)
Kpt = PTI (Palomar Testbed Interferometer)
Kpu = Pulkovo Stellar Interferometer
Ksu = SUSI (Sydney University Stellar Interferometer)
Kva = VLTI/AMBER
Kvl = VLA
Occ = occultation (note: projected separation; "V" preceding
angle indicates vector direction. Position angle with
no "V" code indicates true separation and angle from
triangulation of two or more occultation measures)
Pgi = phase grating interferometer
Pmi = Michelson interferometer
Qac = HST + ACS
Qfg = HST + Fine Guidance Sensor
Qfo = HST + Faint Object Camera
Qir = Spitzer Space Telescope and IRAC
(Infrared Array Camera)
Qmi = Spitzer Space Telescope and MIPS
(Multiband Imaging Photometer for Spitzer)
Qni = HST + NICMOS IR direct imaging
Qpc = HST + WFPC2 Planetary Camera
Qst = HST + STIS
Qsx = Spitzer Space Telescope and SpeX spectrometer and
slit-viewing camera
Qwi = WISE IR satellite (IR imaging)
Spe = speckle interferometric technique
Sam = aperture masking technique (MAPPIT, etc.)
Sbi = bispectrum speckle interferometric technique
Sch = CHARA speckle
Sir = IR speckle
Spo = speckle polarimetry
Ssa = shift-and-add technique
Sus = USNO speckle
Thp = Hipparcos
Tty = Tycho
U = adaptive optics
Uam = adaptive optics with aperture mask
Uco = adaptive optics coronagraph
Uch = CHARA adaptive optics
Ucw = adaptive optics with coronagraph and "well-corrected
subaperture"
Uds = AO + dark speckle coronagraph
Ula = laser-guided AO
Usd = adaptive optics spectral deconvolution technique
Usi = adaptive optics imaging, keeping only selected images
("lucky imaging")
Zhr = high-resolution spectroscopy
Zlr = low-resolution spectroscopy
Zre = resolved spectroscopy
Zsp = spectrophotometry
Zpt = photometer