This file contains information from the Tycho catalogue, [83], for the stars used as ISO guide stars. This file is not a full extract of the Tycho catalogue, but a subset. Users are recommended to refer to the Tycho catalogue for further information on the contents of this file. It was used in some detailed pointing corrections and was not designed to be of use to the general observer.
The TYCHO file contains a primary header with the fields described in Table D.38. In this example non-mandatory fields are filled with example values.
| Keyword | Value | Description |
| SIMPLE = | T | / |
| BITPIX = | 8 | / |
| NAXIS = | 0 | / |
| EXTEND = | T | / |
| ORIGIN = | 'ESA ' | / European Space Agency |
| TELESCOP = | 'ISO ' | / Infrared Space Observatory |
| COMMENT | ISO guide-star Tycho catalogue data | |
| FILENAME = | 'TYCHO ' | / File name in ISO archive |
| DATE = | '09/07/95' | / Creation date |
| FILEVERS = | '0298 ' | / Version ID in ISO archive |
| OLPVERS = | 'OLP_21 ' | / SOC OLP system version |
| CALGVERS = | 'CALG_31 ' | / SOC OLP CAL-G files version |
| USERNAME = | 'PIPELINE' | / |
| CREATOR | 'OLP_CREATE v1.0' | / Task which created the file |
| CALIBRAT = | 'CAL-G v5.6' | / Calibration Data release |
| TIME = | '22:59:29' | / Time of file creation (hh:mm:ss) |
| DATE-OLD = | '1999-08-16' | / Date of original creation by IDT |
The TYCHO file contains records described in Table D.39.
| Keyword | Number | Format | Description |
| T1 | 3 | I2 | TYC identifier |
| T0 | 1 | C1 | Catalogue (T = Tycho) |
| T2 | 1 | C1 | Proximity flag |
| T3 | 1 | C12 | Identifier RA(J1991.25), as `h m s' |
| T4 | 1 | C12 | Identifier Dec(J1991.25), as `d m s' |
| T5 | 1 | R4 | Johnson V magnitude |
| T6 | 1 | C4 | Blank |
| T8 | 1 | R8 | alpha(J1991.25), in degrees |
| T9 | 1 | R8 | delta(J1991.25), in degrees |
| T11 | 1 | R8 | Trigonometric parallax, in mas |
| T12 | 1 | R8 | mu_alpha*, in mas/year |
| T13 | 1 | R8 | mu_delta, in mas/year |
| T14 | 1 | R8 | Standard error in alpha(J1991.25), in mas |
| T15 | 1 | R8 | Standard error in delta(J1991.25), in mas |
| T16 | 1 | R8 | Standard error in pi, in mas |
| T17 | 1 | R8 | Standard error in mu_alpha*, in mas/year |
| T18 | 1 | R8 | Standard error in mu_delta, in mas/year |
| T19 | 1 | R4 | Correlation: alpha*/delta |
| T20 | 1 | R4 | Correlation: alpha*/pi |
| T21 | 1 | R4 | Correlation: delta/pi |
| T22 | 1 | R4 | Correlation: alpha*/mu_alpha* |
| T23 | 1 | R4 | Correlation: delta/mu_alpha* |
| T24 | 1 | R4 | Correlation: pi/mu_alpha* |
| T25 | 1 | R4 | Correlation: alpha*/mu_delta |
| T26 | 1 | R4 | Correlation: delta/mu_delta |
| T27 | 1 | R4 | Correlation: pi/mu_delta |
| T28 | 1 | R4 | Correlation: mu_alpha*/mu_delta |
| T29 | 1 | I4 | Data points rejected, in percent |
| T30 | 1 | R4 | F2 (goodness-of-fit) |
| T31 | 1 | I4 | HIP number |
| T32 | 1 | R4 | BT, in magnitudes |
| T33 | 1 | R4 | sigma(BT), in magnitudes |
| T34 | 1 | R4 | VT, in magnitudes |
| T35 | 1 | R4 | sigma(VT), in magnitudes |
| T37 | 1 | R4 | B V, in magnitudes |
| T38 | 1 | R4 | sigma(BV), in magnitudes |
| T41 | 1 | R4 | S/N ratio, in magnitudes |
| T44 | 1 | R4 | V(T) scatter, in magnitudes |
| T45 | 1 | R4 | Magnitude at maximum VT (5th percentile), in magnitudes |
| T46 | 1 | R4 | Magnitude at minimum VT (95th percentile), in magnitudes |
| T7 | 1 | C1 | Source of magnitude identifier |
| T10 | 1 | C1 | Reference flag for astrometry |
| T36 | 1 | C1 | Reference flag for BT and VT |
| T40 | 1 | I1 | Astrometric quality flag |
| T42 | 1 | C1 | Source of astrometric data |
| T43 | 1 | I1 | N(photom) |
| T47 | 1 | C1 | Variability (from GCVS/NSV) |
| T48 | 1 | C1 | Variability (from Tycho) |
| T49 | 1 | C1 | Duplicity (from Tycho) |
| T50 | 1 | C1 | Flag (epoch data) |
| T51 | 1 | C2 | CCDM component Identifier |
| T52 | 1 | I4 | PPM identifier |
| T53 | 1 | I4 | HD identifier |
| T54 | 1 | C10 | DM (BD) identifier |
| T55 | 1 | C10 | DM (CoD) identifier |
| T56 | 1 | C10 | DM (CPD) identifier |
| T57 | 1 | C1 | Notes flag |
| T39 | 1 | C1 | Blank |
| SPARE | 36 | I1 | Spare space |