Information on symbols and units used
Other Name
The Other Name is either the usual name or the designation in one of
the following main catalogues (in order of preference):
Spectral Type
For the vast majority of sources the
Spectral Type is derived from the
Simbad database.
The
icon indicates objects for which this is not the case.
Keeping the mouse positioned on the icon for 2-3 seconds pop-ups a yellow box with more detailed information.
Bibliography
The Bibliography column gives
the following information :
- ADS - link to the ADS abstract service.
The link opens an ADS page with a list of publications which refer to the object.
- all other links - id's of selected publications. When clicked, a DOI: or Bibcode (via adsabs) name resolver will
be called, and a link to an electronic version of the publication will be shown. note: the availability of the full text version of the
publication may be limited to the journal(s) subscribers only.
SED Diagrams
The following formulae are used to derive
diagram data point coordinates :
Tycho2 BT X[um] = 0.435 Y[Jy] = 4000.0 * 10^(-0.4 * Mag)
Tycho2 VT X[um] = 0.505 Y[Jy] = 3700.0 * 10^(-0.4 * Mag)
GSC2 R X[um] = 0.70 Y[Jy] = 2850.0 * 10^(-0.4 * Mag)
GSC2 B X[um] = 0.44 Y[Jy] = 4270.0 * 10^(-0.4 * Mag)
GSC2 V X[um] = 0.55 Y[Jy] = 3900.0 * 10^(-0.4 * Mag)
Denis I X[um] = 0.82 Y[Jy] = 2499.0 * 10^(-0.4 * Mag)
Denis J X[um] = 1.25 Y[Jy] = 1595.0 * 10^(-0.4 * Mag)
Denis K X[um] = 2.15 Y[Jy] = 665.0 * 10^(-0.4 * Mag)
2MASS J X[um] = 1.235 Y[Jy] = 1594.0 * 10^(-0.4 * Mag)
2MASS H X[um] = 1.66 Y[Jy] = 1024.0 * 10^(-0.4 * Mag)
2MASS K X[um] = 2.16 Y[Jy] = 666.7 * 10^(-0.4 * Mag)
MSC6X A X[um] = 8.28 Y[Jy] = Jy
MSC6X C X[um] = 12.13 Y[Jy] = Jy
MSC6X D X[um] = 14.65 Y[Jy] = Jy
MSC6X E X[um] = 21.34 Y[Jy] = Jy
IRAS Fnu12 X[um] = 12 Y[Jy] = Jy
IRAS Fnu25 X[um] = 25 Y[Jy] = Jy
IRAS Fnu60 X[um] = 60 Y[Jy] = Jy
IRAS Fnu100 X[um] = 100 Y[Jy] = Jy
Only "good" photometric data are plotted, that is no upper limits,
from GSC2, TYCHO-2, 2MASS, DENIS, MSX6C, IRAS catalogues. Specifically, data points
with the following quality flags are excluded from the plot :
- IRAS: qualityflag = 1
- 2MASS: qualityflag = E/X/U/F
- MSX6C: qualityflag = 1
To obtain the SED in Jy, click on SED [Jy] link, to obtain the
SED in erg cm-2 s-1 click on SED [erg cm-2 s-1].
Spectroscopic Data
ISO: - when available, an ISO spectrum
is overplotted on the SED diagram. The ISO observation identifier from which data were taken is given in the
TDT field. Details on how the ISO spectra were processed, are given to the catalogue's official reference.
IRAS: Low Res Spectrum - when available
a low resolution IRAS spectrum is overplotted on the SED diagram. The spectrum has the absolute calibration corrected as in Volk
and Cohen (1989; Astron.J., 98, 1918) and Cohen, Walker, and Witteborn (1992; Astron.J., 104, 2030). The data points are
taken from
http://www.iras.ucalgary.ca/~volk/getlrs_plot.html
using
corrected raw text format.
Photometric Data
HD: Ptm Ptg - Photovisual & Photographic magnitude in HD catalogue
HD(Nesterov): Ptm Ptg - Photovisual & Photographic magnitude in HD(Nesterov) catalogue
SAO: P V - Photographic & Visual magnitude in SAO catalogue
GSC: P err - photographic magnitude & Mean error on photographic magnitude
in The HST Guide Star Catalog, Version GSC-ACT
GSC2: R e_R B e_B V e_V - Magnitude in F photographic band (red) & Mean
error on Rmag & Magnitude in J photographic band (blue) & Mean error
on Bjmag & Magnitude in V photographic band (green) & Mean error on
Vmag in The GSC 2.2 Catalogue
TYCHO-2: BT e_BT VT e_VT - Tycho-2 BT magnitude & error of BT & Tycho-2 VT
magnitude & error of VT in The Tycho-2 Catalogue. Approximate Johnson photometry may be obtained as:
V = VT - 0.090 * (BT - VT)
B-V = 0.850 * (BT - VT)
IRAS: Fnu_12 Fnu_25 Fnu_60 Fnu_100 qqqq - Average non-color corrected flux
density, 12um & Average non-color corrected flux density, 25um & Average
non-color corrected flux density, 60um & Average non-color corrected
flux density, 100um & Flux density quality in each band
2MASS: J H K Qflg - J selected default magnitude & H selected default
magnitude & K selected default magnitude & JHK Photometric quality flag
in 2MASS All-Sky Catalog of Point Sources. Three character flag, one character per band [JHK],
that provides a summary of the net quality of the default photometry
in each band, as derived from the Read Flag (Rflg), measurement
uncertainties ([jhk]cmsig), scan signal-to-noise ratios ([jhk]snr),
frame-detection statistics (Ndet), and profile-fit reduced chi-squared
values ([jhk]psfchi). The value for Qflg is set for a band
according to the precedence of the table below. For example, a source
that is tested and meets the conditions for category "X" is not tested
for subsequent qualities.
- X - There is a detection at this location, but no valid brightness
estimate can be extracted using any algorithm. Rflg="9" and
default magnitude is null.
- U - Upper limit on magnitude. Source is not detected in this band
(Rflg="0"), or it is detected, but not resolved in a consistent
fashion with other bands (Rflg="6"). A value of Qflg="U"
does not necessarily mean that there is no flux detected in this
band at the location. Whether or not flux has been detected can
be determined from the value of Rflg. When Rflg="0", no flux
has been detected. When Rflg="6", flux has been detected at the
location where the images were not deblended consistently in all
three bands (JHKs).
- F - This category includes Rflg="1" or Rflg="3" sources where a
reliable estimate of the photometric error, [jhk]cmsig, could
not be determined. The uncertainties reported for these sources
in [jhk]cmsig and e_[jhk]mag are flags and have numeric
values >8.0.
- E - This category includes detections where the goodness-of-fit
quality of the profile-fit photometry was very poor (Rflg=2 and
[jhk]psfchi>10.0), or detections where psf fit photometry did
not converge and an aperture magnitude is reported (Rflg=4), or
detections where the number of frames was too small in relation
to the number of frames in which a detection was geometrically
possible (Rflg="1" or Rflg="2").
- A - Detections in any brightness regime where valid measurements
were made (Rflg="1","2" or "3") with
[jhk]snr>10 AND [jhk]cmsig<0.10857.
- B - Detections in any brightness regime where valid measurements
were made (Rflg="1","2" or "3") with
[jhk]snr>7 AND [jhk]cmsig<0.15510.
- C - Detections in any brightness regime where valid measurements
were made (Rflg="1","2" or "3") with
[jhk]snr>5 AND [jhk]cmsig<0.21714.
- D - Detections in any brightness regime where valid measurements
were made (Rflg="1","2" or "3") with
no [jhk]snr OR [jhk]cmsig requirement.
MSX6C: A C D E q_A q_C q_D q_E - Flux density in A (8.28um) band & Flux
density in C (12.13um) band & Flux density in D (14.65um) band & Flux
density in E (21.34um) band & Band A quality & Band C quality & Band D
quality & Band E quality. The Quality flags in each band are:
- 4 = excellent, SNim >= 10.0
- 3 = good, 7.0 <= SNim < 10.0 or SNim = -800 and SNpsx >= 10.0
- 2 = fair, 5.0 <= SNim < 7.0 or SNim = -800 and 5.0 <= SNpsx < 10.0
- 1 = limit, SNim < 5.0
DENIS: I e_I J e_J K e_K - Magnitude in I band from PSF fit & Magnitude
error in I band from PSF fit & Magnitude in J band from PSF fit &
Magnitude error in J band from PSF fit & Magnitude in K band from PSF
fit & Magnitude error in K band from PSF fit in The DENIS database