Information on Service 'ARIHIP astrometric catalogue'

For a list of all services and tables belonging to this service's resource, see Information on resource 'ARIHIP astrometric catalogue'

Service Documentation

The ARIHIP Catalogue is a suitable combination of the results of the HIPPARCOS astrometry satellite with ground-based data.

The ARIHIP contains 90842 stars in total. The best astrometric data for 90072 of these ARIHIP stars have been selected from the direct solutions given in the combination catalogues FK6(I), FK6(III), GC+HIP, and TYC2+HIP. Such direct solutions are appropriate for single stars or for objects which can be treated like single stars. For these 90072 stars with direct solutions, ground-based measurements have contributed to the astrometric data (mainly to the proper motions).

In addition the ARIHIP contains the original HIPPARCOS solutions for 770 stars which do not occur in one of these combination catalogues but are basically qualified for direct solutions.

Besides the astrometric data, the ARIHIP provides a variety of flags which inform about the known (or possible) binarity of each object. From the 90842 stars in the ARIHIP we have selected 73023 objects as "astrometrically excellent stars", since their instantaneous proper motions and mean (time-averaged) ones do not differ significantly. Hence most of the astrometrically excellent stars are well-behaving "single-star candidates" with good astrometric data. These stars are most suited for high-precision astrometry.

On the other hand, 2827 of the stars in the ARIHIP are Δμ binaries in the sense of Wielen et al. (1999). Many of them are newly discovered probable binaries with no other hitherto known indication of binarity. The ARIHIP gives, besides the classical "single-star mode" solutions (SI mode), other solutions which take into account the fact that hidden astrometric binaries among "apparently single-stars" introduce sizable "cosmic errors" into the quasi-instantaneously measured HIPPARCOS proper motions and positions.

The ARIHIP gives in addition to the SI mode the "long-term prediction (LTP) mode" and the "short-term prediction (STP) mode". These LTP and STP modes are on average the most precise solutions for apparently single stars, depending on the epoch difference with respect to the HIPPARCOS epoch of about 1991. The typical mean error of an ARIHIP proper motion in the single-star mode is 0.89 mas/year. This is about a factor of 1.3 better than the typical HIPPARCOS errors for these stars of 1.13 mas/year.

In the long-term prediction mode, in which cosmic errors are taken into account, the ARIHIP proper motions have a typical mean error of 1.15 mas/year, which is by a factor of more than 1.6 better than the corresponding error for the HIPPARCOS values of 1.89 mas/year (cosmic errors included).

Overview

You can access this service using:

• static -- static (i.e. prepared) data or custom client-side code; probably used to access ancillary files here
• form -- allows access via an HTML form
• scs.xml -- a standard SCS interface as defined by the IVOA to access catalog-type data; SCS clients use https://herschel-vos.phys.sussex.ac.uk/arihip/q/cone/scs.xml? to access the service

VOResource XML (that's something exclusively for VO nerds)

Note bin

The column Kbin describes the multiplicity of the object. In consists of up to two digits.

The first digit describes the evidence for the multiplicity of the object based on proper-motion differences. For details on the method and the various test parameters F see Wielen et al (1999a).

1	all values of F (F_{FH}, F_{0H}, F_{0(GC)H}, F_{0F}, F_{TH}) are below 2.49
2	at least one value of F (F_{FH}, F_{0H}, F_{0(GC)H}, F_{0F}, F_{TH}) is larger than 3.44
3	all other (intermediate) cases
	empty means no F value(s) are available

The second digit gives evidence for the multiplicity of the object based on non-PM methods. If the data indicate various kinds of binarity, the 'astrometrically most disturbing' effect is given. :

1

single star indicated

2

the star is a member of a visual binary (gravitationally bound system), or the object is resolved by speckle interferometry

3

the object is suspected to be a visual binary (mainly due to HIP)

4

the star has at least one optical companion with a separation of rho < 60"

5

the star has at least one optical companion, but all companions have a separation of rho <= 60"

6

astrometric binary (mainly the non-standard solutions O, G, V, X of HIP)

7

spectroscopic binary with a known orbit, or the star is an eclipsing binary

8

the radial velocity of the star is variable (indicating a spectroscopic binary), or the object shows a composite spectrum (indicating a double star)

9

the radial velocity of the star may be variable (possible indication for a spectroscopic binary), or the object may show a composite spectrum (possibly indicating a double star), or other weak indications of binarity, or the star has a (suspected) planetary companion

Note src

The srcSel field indicates which catalogue the astrometric solution was taken from using the following codes:

F61	Part I of the FK6 (Wielen et al. 1999d)
F63	Part III of the FK6 (Wielen et al. 2000a)
GCH	GC+HIP Catalogue (Wielen et al. 2001b)
T2H	TYC2+HIP Catalogue (Wielen et al. 2001c)
HIP	HIPPARCOS Catalogue (ESA 1997)

Note tabflags

The flags field collects a number of flags related to indications of multiplicity. The flags are organized into columns in the form H UF KC GBST AML VPI. The individual columns mean:

Column H

HIPPARCOS indicators for a suspected visual binary:

s	Flag S in HIP Field H61
d	Flag D in HIP Field H52, based on photometry.
t	HIP Flags S and D (t = s+d).

Column U

HIPPARCOS percentage of rejected data (HIP Field H29, F1); one digit: 0, 1, 2, ... percent; 9: 9 or more percent. A high percentage of rejected data may be caused by a duplicity of the object, but other reasons cannot be excluded.

Column F

HIPPARCOS goodness-of-fit parameter (HIP Field H30, F2):

	F2 < 0
0	0 <= F2 < 1
1	1 <= F2 < 2
2	2 <= F2 < 3
3	3 <= F2 < 4
4	4 <= F2 < 5
etc.
8	8 <= F2 < 9
9	9 <= F2

A large value of F2 (e.g. larger than 3) may be caused by a duplicity of the object, but other reasons cannot be excluded.

Column K

Indications on binarity provided by the catalogue of speckle observations (Hartkopf et al. 1999).

b

binary resolved by speckle (or other interferometric) observations (such objects are generally excluded from the ARIHIP)

u

possibly resolved

n

object observed, but not resolved (i.e. no hint to binarity)

Column C

Indicator for a star which has one (or more) visual component(s) with a separation rho of at least 60". Source of information:

c	CCDM (Dommanget and Nys 1994)
t	TYCHO2 (Hoeg et al. 2000)
w	WDS (Worley and Douglass 1997, and updated versions)
r	other sources

Visual binaries with rho < 60" are generally excluded from the ARIHIP.

Column G

Indications on binarity provided by the General Catalogue of Stellar Radial Velocities (GCRV, Wilson 1953):

v	radial velocity is variable
u	radial velocity may be variable
2	variable radial velocities for two stellar components
b	(other) indications of binarity
d	(other) indications of binarity are doubtful

Column B

Indications on binarity provided by the Bright Star Catalogue (BSC, Hoffleit and Jaschek 1982). The symbols v, u, 2, b, d have the same meaning as explained for Column G.

Column S

Indications on binarity provided by the radial-velocity bibliography given in the data block 'oRV' of SIMBAD (CDS Strasbourg). The symbols v, u, 2, b, d have the same meaning as explained for Column G.

Column T

Indications on binarity provided by the spectral-type bibliography given in the data block 'MK' of SIMBAD (CDS Strasbourg); b means binary, u means possibly a binary.

Column A

Indications on binarity provided by the Third Bibliographic Catalogue of Stellar Radial Velocities (Barbier-Brossat et al. 1994). The symbols v, u, 2, b, d have the same meaning as explained for Column G.

Column M

Indications on binarity provided by the Bibliographic Catalogue of Stellar Radial Velocities 1991-1998 (Malaroda et al. 2001). The symbols v, u, 2, b, d have the same meaning as explained for Column G; additionally, f denotes "probably erroneous indication on binarity"

Column L

Indications on binarity from additional literature (e.g. from papers more recent than those used for Column M). The symbols v, u, 2, b, d have the same meaning as explained for Column G. Additionally, c means that the radial velocity is probably constant.

Column V

Indications on binarity from photometric variability.

a	eclipsing binary, Algol type
b	eclipsing binary, beta Lyrae type
e	eclipsing binary, type uncertain
w	eclipsing binary, W Ursae Majoris type

Column P

Indicator for a variability of the radial velocity V_rad due to stellar pulsation (which may be confused with a variability of V_rad due to spectroscopic binarity).

c	Cepheid
s	delta Scuti star
b	beta Cephei star

Column I

An i here means that an individual note on this star is given in Part I (1-560) or III (3001-3024) of the FK6

Note var

The Km flag indicates the variability of the source and is taken from the HIPPARCOS catalogue. The codes denote:

empty	star not variable
1	star variable at the level of < 0.06 mag
2	star variable at the level of 0.06 - 0.6 mag
3	star variable at the level of > 0.6 mag