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 col 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 have been merged with those in the WDS and
all other USNO double star catalogs. The list below includes all
codes used in these catalogs, even if not in the interferometric
catalog (old WDS and interferometric catalog codes are included as
well):
new old description
A U = adaptive optics
Ac Uch = CHARA adaptive optics
Ad Usd = adaptive optics spectral deconvolution technique
Ag Ula = laser-guided AO
Al Usi = adaptive optics imaging, keeping only selected images
("lucky imaging")
Am Uam = adaptive optics with aperture mask
Ao Uco = adaptive optics coronagraph
As Uds = AO + dark speckle coronagraph
Aw Ucw = adaptive optics with coronagraph and "well-corrected
subaperture"
C F = CCD or other two-dimensional electronic imaging
Ca W = Area scanner
Cc Fic = IR coronagraph
Ce L = Electronographic camera
Ci Fir = IR direct imaging
Cl Fsi = short-exposure CCD imaging, keeping only selected
images ("lucky imaging")
Cp Fip = IR imaging polarimetry
Cs Fss = IR one-dimensional slit scanning
Cu F = USNO CCD imaging (speckle-style reduction)
D D = Heliometer
E E = Wide-field CCD or other two-dimensional electronic
imaging
E2 E2m = 2MASS (Two Micron All-Sky Survey)
Ed Ede = DENIS (Deep Near-Infrared Survey)
Ek Euk = UKIDSS (UKIRT Infrared Deep Sky Survey)
Es Esd = SDSS (Sloan Digital Sky Survey)
Eu Eu3 = UCAC3
Eu Eu4 = UCAC4
Ey = Yale SPM (Southern Proper Motion) Survey
H T = Hipparcos/Tycho, HST, or other space-based technique
H Q = Hipparcos/Tycho, HST, or other space-based technique
Ha Qac = HST + ACS
Hc Ech = Chandra
He Eei = Einstein
Hf Qfg = HST + Fine Guidance Sensor
Hg = Gaia
Hh Thp = Hipparcos
Hi Qir = Spitzer Space Telescope + IRAC (Infrared Array Camera)
Hk = Kepler
Hm Qmi = Spitzer Space Telescope + MIPS (Multiband Imaging
Photometer for Spitzer)
Hn Qni = HST + NICMOS IR direct imaging
Ho Qfo = HST + Faint Object Camera
Hp Qpc = HST + WFPC2 Planetary Camera or Wide Field Camera 3
Hs Qst = HST + STIS
Ht Tty = Tycho
Hw Qwi = WISE (Wide-field Infrared Survey Explorer) satellite
(IR imaging)
Hx Qsx = Spitzer Space Telescope + SpeX spectrometer and
slit-viewing camera
Hz = XMM Newton satellite
I P = interferometric technique
Ig Pgi = phase grating interferometer
Im Pmi = Michelson interferometer
J J = visual interferometer
Jm Jmw = Mount Wilson 100-inch telescope rotating interferometer
(Anderson, Merrill)
Jp Jpe = Mount Wilson 20-foot beam interferometer (Pease)
K K = long-baseline visual/IR/radio interferometer
K2 Kce = CERGA 2-telescope interferometer
Ka Kva = VLTI/AMBER
Kb Kbi = BIMA
Kc Kch = CHARA Array
Ke Kev = European VLBI network
Kf Kcs = CHARA Array (separated fringe packet data)
Kg Kgl = global VLBI array
Ki Kio = IOTA
Kk Kki = Keck interferometer
Kl Kvl = VLA
Kl Kvb = VLBA
Km Km3 = Mark III
Kn Knp = NPOI (Navy Prototype/Precision Optical Interferometer)
Kp Kpt = PTI (Palomar Testbed Interferometer)
Kr Kap = radio/IR aperture synthesis technique
Ks Ksu = SUSI (Sydney University Stellar Interferometer)
Ku Kpu = Pulkovo Stellar Interferometer
M A = micrometry technique
Ma A = micrometer with refractor
Mb B = micrometer with reflector
Mc C = Comparison image micrometer
Md N = Visual measures with a double-image micrometer
Mg = illuminated-reticle micrometer
(e.g. Celestron Micro-Guide)
Mr R = RGO use of micrometer plus comparison image micrometer
on same star
O O = occultation
O Occ = occultation
P G = photographic technique
Pa G = photographic, with astrograph
Pb G = USNO-B astrograph data
Pc Gac = Astrographic Catalog
Pe G = ESO Schmidt astrograph
Pk Gag = AGK Catalog
Po H = photographic, with medium or long-focus technique or
with ocular enlargement
Pp Gp1 = Palomar Observatory Sky Survey (POSS-I)
1948-1958, 48in/1.2m Schmidt
Pp Gp2 = Palomar Observatory Sky Survey (POSS-II)
1985-1999, 48in/1.2m Schmidt
Pu Guk = UK Schmidt Southern Survey
1974-1987, 48in/1.2m Schmidt
S Spe = speckle interferometric technique
Sa Sam = aperture masking technique (MAPPIT, etc.)
Sb Sbi = bispectrum speckle interferometric technique
Sc Sch = CHARA speckle
Si Sir = IR speckle
Sp Spo = speckle polarimetry
Ss Ssa = shift-and-add technique
St S = Tokovinin speckle camera (SOAR)
Su Sus = USNO speckle
T M = Transit circle / Meridian circle
Tm I = "Eyepiece micrometer" transit/chronometric technique
V = visual estimate
X = spectroscopic technique
Xg X = Visual estimate made with an objective grating
Xh Zhr = high-resolution spectroscopy
Xl Zlr = low-resolution spectroscopy
Xr Zre = resolved spectroscopy
Xs Zsp = spectrophotometry
Z Z = photometric technique
Z Zpt = photometer
Zc = CCD photometry
Zd V = Photocell with diaphragm in focal plane
Zp Z = Visual photometry with a double-image or polarizing
photometer
Zw Y = Wedge photometer