5a) Files z001 to z288 ("u2" directory)
----------------------
These files constitute the main data of the catalog. All items are
(signed) integer. "I*1" means the data for these items are contained
in 1 byte, "I*2" means 2 bytes, etc. The order of bytes is for an
Intel processor. Each record contains the data for one star, totaling
23 items. The record length is 44 bytes, with no additional "end of
line" or unformatted leading or trailing bytes. In Fortran this is
known as a direct access, fixed record length, unformatted file.
(Note, some compilers specify the record length as multiple of
4-byte segments, thus RECL=11 is required in that case,instead
of RECL=44 which applies to other compilers. RECL=44 is used in the
utility software provided on these CDs.)
The following items are on each star record:
Num Bytes Fmt Unit Label Explanation
-----------------------------------------------------------------------------
1 1- 4 I*4 mas RA Right Ascension at epoch J2000.0 (ICRS) (2)
2 5- 8 I*4 mas DE Declination at epoch J2000.0 (ICRS) (2)
3 9-10 I*2 0.01 mag U2Rmag Internal UCAC magnitude (red bandpass) (3)
4 11 I*1 mas e_RAm s.e. at central epoch in RA (*cos DEm)(1,4)
5 12 I*1 mas e_DEm s.e. at central epoch in Dec (1,4)
6 13 I*1 nobs Number of UCAC observations of this star(5)
7 14 I*1 e_pos Error of original UCAC observ. (mas) (1,6)
8 15 I*1 ncat # of catalog positions used for pmRA, pmDC
9 16 I*1 cflg ID of major catalogs used in pmRA, pmDE (7)
10 17-18 I*2 0.001 yr EpRAm Central epoch for mean RA, minus 1975 (8)
11 19-20 I*2 0.001 yr EpDEm Central epoch for mean DE, minus 1975 (8)
12 21-24 I*4 0.1 mas/yr pmRA Proper motion in RA (no cos DE) (9)
13 25-28 I*4 0.1 mas/yr pmDE Proper motion in DE (9)
14 29 I*1 0.1 mas/yr e_pmRA s.e. of pmRA (*cos DEm) (1)
15 30 I*1 0.1 mas/yr e_pmDE s.e. of pmDE (1)
16 31 I*1 0.05 q_pmRA Goodness of fit for pmRA (1,11)
17 32 I*1 0.05 q_pmDE Goodness of fit for pmDE (1,11)
18 33-36 I*4 2m_id 2MASS pts_key star identifier (12)
19 37-38 I*2 0.001 mag 2m_J 2MASS J magnitude (13)
20 39-40 I*2 0.001 mag 2m_H 2MASS H magnitude (13)
21 41-42 I*2 0.001 mag 2m_Ks 2MASS K_s magnitude (13)
22 43 I*1 2m_ph 2MASS modified ph_qual flag (1,14)
23 44 I*1 2m_cc 2MASS modified cc_flg (1,15)
-----------------------------------------------------------------------------
Example:
As an example, the data of the first 5 stars from z001 are
printed here in ASCII. These are the numbers obtained when
using the u2dumpz.f program.
item 1 2 3 4 5 6 7 8 9 10 11 12
1246420 -322767602 1591 75 87 2 97 2 1 17330 15213 31020
4125230 -323707012 1382 15 28 8 21 2 1 23246 22659 134316
7345118 -322447512 1579 24 26 4 25 2 1 22903 22799 45845
8139385 -322284308 1479 53 25 5 41 2 1 20455 22911 18125
11128880 -323115466 1631 15 43 2 27 2 1 23364 21562 39404
item 13 14 15 16 17 18 19 20 21 22 23
-35 70 74 20 20 1229086517 14428 13865 13751 000 000
-187 61 62 20 20 1101364107 12467 12131 11963 000 000
104 61 62 20 20 1329022468 14169 13752 13708 220 000
-16 65 61 20 20 1085341332 13111 12511 12339 000 000
-74 61 63 20 20 1085341834 14515 13918 13877 000 000
Note (1): In order to fit within the range of a 1 byte (signed)
integer (-127 to +127), some items have an offset value of -127
applied. These are items #4,5 (e_RAm, e_DEm), #7 (e_pos),
#14-17 (e_pmRA, e_pmDE, q_pmRA, q_pmDE), and #22,23 (2m_ph, 2m_cc).
When using the provided software, the data items are converted to
I*4 and automatically corrected for this offset on the required items.