# Tag Info

## Hot answers tagged star-catalogues

8

As far as I know, there is no standard that defines valid characters for a stellar designation. Sometimes people write using Greek letters (e.g. "α Centauri") and there are many odd catalogue notations. I would not trust that star designations could not contain commas or pipes (aka vertical bar, |), although I think it would be rare. The IAU has ...

6

Variable stars might challenge this. A distant Mira type variable or recurrent nova could have been at its minimum when the (for example) Gaia catalogue was being assembled, but appear in an amateur photographs. These stars undergo very large variation in brightness. Mira can increase in brightness by 8 magnitudes, so it is not inconceivable that an ...

3

The Hipparcos results can be used as an earlier epoch to improve the astrometry produced by Gaia. This was the linchpin of data release 1 (DR1), but less important in DR2 and DR3, because the astrometry of Gaia alone is so much better in general. An exception to this is bright stars where much data is still missing in DR3, but can be found in the Hipparcos ...

3

For Gaia EDR3： Note (G1): Note on magnitude errors: They are obtained with a simple propagation of errors with the formulas e_Gmag = sqrt((-2.5/ln(10)*e_FG/FG)**2 + sigmaG_0**2) e_GBPmag = sqrt((-2.5/ln(10)*e_FGBP/FGBP)**2 + sigmaGBP_0**2)) e_GRPmag = sqrt((-2.5/ln(10)*e_FGRP/FGRP)**2 + sigmaGRP_0**2)) with the G, G_BP, G_RP zero point uncertainties ...

3

That is because what is measured is a flux and the flux errors are in the DR2 catalogue. Since magnitudes are based on the logarithm of the flux, then there is no straightforward correspondence (although it matters little if the error bars are less than a few hundredths if a magnitude). Simple error propagation formulae give |\Delta G| \simeq \frac{2.5}{\...

3

For me, it looks like Max Wolf discovered the movements of the Wolf 359, see the (German) original publication from 1918 "Zwei Sterne mit großer Eigenbewegung in Leo," but he does not mention which previous observations existed: Fun fact: The object was observed from Königstuhl, a peak next to the city of Heidelberg, Germany. That was back in the ...

3

The SIMBAD link might be there just because Osterbrock's 2004 AAS presentation about the interferometer mentioned an observation of Betelgeuse. This would be consistent with the policy stated in Wenger et al. 2000: No assessment is made of the relevance of the citation in terms of astronomical contents: the paper can be entirely devoted to the ...

3

Note that astronomers generally are not concerned with hemispheres, so it is unlikely that you will find a catalog that is only for a specific hemisphere. Catalog generally cover the entire sky. Also, most catalogs are for either stars or deep sky objects (galaxies, nebulae, and so on). I have not seen a catalog that includes both stellar and non-stellar. ...

2

30.0 mean "variable". If you click on the "Ptm" column header, you get a pop-up window including "Note (2) : codes used for the magnitudes:"; below that is a list of codes, including "30.0 = variable (var. in published catalog)"

2

It's pretty simple: those are the names of the named stars, also called 'proper names'. All other designations you show in your table are catalogue numbers assigned to them. While these names are historically grown, the official names are assigned / decided by the IAU to avoid confusion and standardize them.

2

As you’ve discovered, there are a lot of different catalogs out there, and many ways to search them. It would help if you could narrow your question a bit - what kind of data are you looking for? You seem to want stellar masses at least - what else? As noted above, there are few stars for which mass is measured directly, but there are robust ways of ...

2

FK5 is based on optical observations. ICRS is based on radio data. Radio observations (ironically) are much higher accuracy than optical through the application of long baseline interferometry. Other than extremely accurate astrometry (fractions of an arcsec), they are essentially identical.

2

$\eta$ Cassiopeiae A has an estimated mass of 0.972 M$_\odot$, an estimated temperature of 5973 K, and a B-V color index of ~0.58[1]. In addition to the spectrum of the star, we look at these and other properties when attempting to classify main sequence stars. You can see a table [here] which shows the bulk properties of each spectral type that we can use ...

2

A catalogue is just that what one would understand usually: it's a table of stars with their coordinates and possibly other properties like relative or absolute brightness, proper motion etc. The accuracy depends on how it was created, thus mostly is expression of the available instrumentation, processing pipeline and its limitations. They usually are output ...

1

Well - not sure why distance and parallax tables are empty, but I missed something super simple, the PLX_VALUE column on the BASIC table. SELECT * FROM BASIC WHERE plx_value IS NOT NULL ORDER BY plx_value DESC OR convert to distance with D = 1000/PLX_VALUE for dist in parsecs

1

The spectral type of a star is determined by looking at its spectrum. Sometimes authors will use other, approximate, relationships between spectral type and colour or mass, or they will look at the spectrum compared with standard templates in different wavelength regions. These are all possible reasons why different sources might suggest slightly different ...

1

Simbad is giving a catalogue of astronomical objects (that are identified in the Simbad catalogue) referred to in the AAS article. This is routinely done for most papers in the recognised astronomical literature. In this case, Betelgeuse appears to be the only star specifically mentioned in that AAS paper (actually just the abstract that is seen on the ADS ...

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