2015-07-17T08:00:00 1000 The first U.S. Naval Observatory Astrometric Robotic Telescope Catalog URAT1 star catalog URAT1 is an observational catalog at a mean epoch between 2012.3 and 2014.6; ot covers the magnitude range 3 to 18.5 in R-band, with a positional precision of 5 to 40 mas. It covers most of the northern hemisphere and some areas down to -24.8° in declination. In the GAVO data center, we left out all columns originating from cross matches with other catalogs; on-the fly crossmatches can be done in our TAP service. Zacharias, N.; Finch, C.; Subasavage, J.; Bredthauer, G.; Crockett, C.; Divittorio, M.; Furguson, E.; Harris, F.; Harris, H.; Henden, A.; Kilian, C.; Munn, J.; Rafferty, T.; Rhodes, A.; Schultheiss, M.; Tilleman, T.; Wieder, G. 2015AAS...22543301Z stars surveys astrometry photographic-photometry NOFS, Arizona CTIO, Chile USNO Robotic Astrometric Telescope Optical Time TT "epoch" Position ICRS Epoch "epoch" "raj2000" "dej2000" Positions are on the International Celestial Reference System (ICRS) as represented by the UCAC4 catalog. Mean observed positions are given at mean epoch of URAT observations (column "Epoch"). Thus the epoch is slightly different from star to star, but it is always in the range between 2012.311 and 2014.679. Note that the position is originally given in mas, i.e. ±3 in the last digit. The 2 years of observing used for this catalog release was split into a total of 38 sets of data (19 each for regular survey and one grating survey). Unless very bright or very faint or variable, a source on the sky should show up in several sets (adjacent sets, 1st and 2nd year at same season...). If an object is within the about 5 to 17.5 mag range and does not show up in several sets it is suspicious and might be a variable or moving source or sometimes blended image. n_sets_used is set negative for stars which were not matched with the GSC 2.4 catalog (about 1.1 million objects, priv. comm. R.Smart). Some of these are fake entries in URAT (like a minor planet at a certain epoch), others appear to be slightly offset from a real star (possible large proper motion object), and others are at the limiting magnitude thesholds. In order to pick a somewhat cleaner sample of URAT reference stars these objects could be avoided This is the mean, observed magnitude in the 680-750 nm URAT bandpass, calibrated by APASS photometry. This bandpass is between R and I, thus further into the red than UCAC. Observations in non-photometric nights *are* included thus the URAT magnitudes need to be taken with caution. Unknown or unrealistic magnitudes are blanked. The faintest maybe real celestial object magnitude is about 19.0, while the URAT1 catalog should be complete to about magnitude 18.0. Each object on every individual exposure and CCD gets a reference star flag assigned during the conventional, astrometric "plate" reduction. The largest value of this flag for a given star over all its observations is carried into this URAT1 catalog flag. The meaning of the values of this flag is as follows: == ============================================================= 0 not a reference star 1 o.k, both coordinates used as reference star 2 x-coord. excluded in adjustment 3 y-coord. excluded in adjustment 4 x and y-coord. excluded in adjustment 5 not selected due to astrometry flag 6 too bright on URAT exposure (amplitude limit exceeded) 7 no valid sigma_xy from profile fit on URAT exposure 8 excluded by distance from URAT center (accepted field of view) 9 excluded because outside of adopted UCAC4 magnitude range == ============================================================= The UCAC4 was used as reference star catalog, however, only "clean" (astrometry flag) UCAC4 stars within the 8.0 to 16.0 mag were used. Thus there are some UCAC4 stars with reference star flag 5 and 9. These are identified, valid UCAC4 stars but were not used as reference stars in the URAT1 astrometric reductions. 0/0-3 1/19,23,27,31 2/69,71,73,75,85-87,89-91,101-103,105-107,117-119,121-123 3/273,283,291,297-299,333-335,337-339,353,355,397-399,401-403,418-419,455,461-463,466-467,481-483,574-575,637-639,701-703,766-767 4/1083,1086-1087,1091,1101,1127,1130-1131,1158-1159,1185-1187,1311,1325,1327,1331,1347,1411,1417-1419,1567,1583,1587,1603,1667,1669-1671,1811,1814-1815,1839,1843,1859,1861-1863,1923,2287,2291,2293-2295,2527,2543,2547,2783,2799,2803,3055,3059 5/4326-4327,4329-4331,4338-4339,4342-4343,4359,4363,4388-4389,4401,4412-4413,4415,4501-4503,4505,4507,4519,4623,4627,4629-4631,4653-4655,4737-4739,5239,5243,5277-5279,5307,5319,5322-5323,5383,5387,5639,5665-5667,6261-6263,6265-6267,6327,6341-6343,6345,6347,6405-6407,6411,6663,6667,6675,7237-7239,7243,7248,7250-7251,7254,7268-7269,7271,7349-7351,7353-7355,7365-7367,7369-7371,7431,7434-7435,7441-7443,7685-7687,7689-7691,9085-9087,9143,9147,9159,9163,9169-9171,10103,10107,10167,10171,10183,10187,11127,11131,11189-11191,11194-11195,11207,11209-11211,12213-12215,12217,12219,12230-12231,12233-12235,12248,12250-12251,12253-12255 6/17151,17295,17298-17300,17302-17303,17314-17315,17346-17348,17350-17351,17362,17366-17367,17429-17431,17433-17435,17445-17447,17449,17451,17540-17541,17543,17560-17561,17563-17566,17600-17602,17613,17615,17636-17637,17639,17656-17657,17659,17997-17999,18002-18003,18017-18019,18025,18027,18056,18058-18059,18071,18075,18487,18507,18513,18515,18581,18590-18591,18605,18607,18609,18611,18945,18947,20949-20951,20953-20955,20965-20967,20969-20971,21103,21107,21188-21189,21191,21221-21223,21225-21227,21269-21271,21273-21275,21282,21285-21287,21525-21527,21529-21531,21543,21547,22549-22551,22553-22555,22565-22567,22573-22575,22657-22659,24959,25023,25039,25043,25059,25303,25307,25319,25324-25325,25327,25359,25363,25379,25387,25619,25637,25639,25642-25643,26649-26651,26661-26663,26665-26667,26695,26697-26699,28943,28947,28965-28967,28969,28971,28996,28998-28999,29010,29022,29060-29061,29063,29080-29081,29083,29109,29119,29311,29375,29391,29395,29411,29455,29459,29475,29723,29735,29761-29763,30735,30739,30755,36317-36319,36333-36335,36337-36339,36567,36569-36571,36581-36583,36585-36587,36635,36647,36651,36673-36675,40405-40407,40409,40411,40423,40426-40427,40661-40663,40665-40667,40677-40679,40681-40683,40725-40727,40729-40731,40741-40743,40745-40747,44415,44501-44503,44505-44507,44517-44519,44521-44523,44671,44735,44751,44755,44773-44775,44823,44827,44835,48063,48106-48107,48767,48847,48851,48867,48911,48915,48918-48919,48931,48970,48989,48991,48998,49009-49011 2012-01-01 2014-12-31 2.879e-19 3.679e-19