johanley/star-catalog

Create a new bright star catalog out of existing catalogs.

star-catalog's Issues

Missing two B-V data points - backfill from SIMBAD

For the 2 records missing B-V, see if they can be backfilled using SIMBAD.

No B-V: 2 [26220, 32609]

Simbad gives a B-V for the first HIP, but not the second.

Close pairs: increase the separation to 120 arcseconds.

One record is missing radial velocity, and I can't find a value for it.

This one missing piece of data means that the catalog doesn't provide complete kinematics. It would be nice to add it somehow, but I can't find a source for it.

This occurred after adding 68 variable stars to the catalog. The star is

HIP 110478
HD 212087
HR 8521
π1 Gru
GCVS 399016

This star is an optical double with pi-2 Gru, not a physical double.

Add a standalone constellation field.

The Bayer and Flamsteed fields include the constellation, but that data is not complete for all records.

It might be necessary to pull in constellation boundaries from some source. Sounds like significant work.

Add some bright variables to the catalog (Mira, Chi Cyg)

Mira:
HD 14386, HIP 10826, HR 681. Its HIP Vmag is 6.47 (near the center of its range). Its BSC Vmag is 3.04.

Chi Cyg:
HD 187796, HIP 97629, HR 7564 In HIP its Vmag is 7.91. Its BSC Vmag is 4.23.

With my Vmag limit of 6.0, the Vmag in their Hipparcos records filters-out these variables from my catalog.

Is there a way of catching all such cases?
The field H6 is a coarse variability flag, which could at least give me a list of candidates for inclusion.
1: < 0.06mag ; 2: 0.06-0.6mag ; 3: >0.6mag

There is a separate variability annex file hip_va_1.dat for periodic variables, whose fields P7 and P9 state the observed max and min magnitudes. The docs for fields P7 and P9 show that these are Hp magnitudes, not Johnson-V:

"Fields P7 and P9 provide the magnitudes at maximum and minimum luminosities.
These were derived from (folded) light-curve fitting on the basis of the Hp photometry
for approximately 90 per cent of the stars in the section of periodic variables"

The Band field (P22) in the variability annex seems to refer only to the literature section, since it seems to appear only when the literature-mag is present.

Sources of the 'literature' fields:
"Information entered in Fields P18–P22 and U18–U22 is largely taken from the General
Catalogue of Variable Stars, 4th edition GCVS; P.N. Kholopov et al., Publ. Office
‘Nauka’, Moscow, 1985–88) and its updates, either through the CDS (Strasbourg), or
from the data base of the American Association of Variable Star Observers (AAVSO),
as communicated by J. Mattei. "

HIP 77990 has misaligned fields.

It looks like one of the error fields is unexpectedly wide.

Issue kindly reported by Lee D.

Is it worthwhile to search for a robust source of Johnson-V magnitudes for bright stars?

See issue #8 for related information.

The docs need to note the limitations of Vmag

From the docs for field H5:

"The V magnitude was not measured directly from the Hipparcos observations, but
derived using a series of transformations according to stellar type and the photometric
information available (see Field H7). As a result, the field provides an approximate
but rather homogeneous indication of the Johnson V magnitude useful, for example,
for identification purposes, and for the computation of absolute magnitudes in terms of
MV . Users should, however, be aware of the limitations arising from its construction."

Note as well the docs for field H7, which states the source of H5:

"The number of entries in each category is as follows: G = 23 139; H = 94 669; T = 409; = 1"

G is ground-based, H is Hipparcos, T is Tycho. So, the majority of the Vmag entries are derived from Hipparcos data, not direct measurements of Johnson-V.

It's interesting to note that this limitation is quite similar to that found in the Yale Bright Star Catalog, which is based on the old Harvard Revised photometry, not Johnson-V.

Consider changing the readme to the standard, fortran-friendly format

The readme files in CDS usually conform to this standard:
http://vizier.u-strasbg.fr/vizier/doc/catstd.htx

Readme should state the position as well as the width of each field.

Detect and report close pairs of records.

When creating star charts for the constellations, it's often necessary to consider close pairs of stars.

The human eye may see a close pair as a single object. In that case, you may want to have the chart reflect what is perceived by the eye, and amalgamate two objects into one.

It's likely useful to generate a list of close pairs present in the catalog, to help people with this task. The limiting distance to use is not well defined.

Ref: https://en.wikipedia.org/wiki/Apparent_magnitude#Magnitude_addition

Verify the Yale BSC doesn't repeat HD values across multiple entries.

I'm using the HD identifier to cross-match my data-set and the Yale Bright Star Catalog.

If the HD is not unique in the Yale BSC, then it would be less suitable as a cross-matching tool.

Search for identifiers that appear in multiple records.

Suggested by Lee D.