SIMBAD references

C. B. Markwardt, University of Maryland and Goddard Space Flight Center (GSFC); and J. H. Swank, GSFC, report that RXTE PCA monitoring observations of the Galactic-center region have revealed a new millisecond pulsar, designated XTE J1814-338. PCA cross scans on June 5.1 UT determined the position to be R.A. = 18h13m.7, Decl. = -33o46' (equinox 2000.0), with a 99-percent confidence radius of 2'. The observation also contained pointed data, during which coherent pulsations were detected at a barycentered frequency of 314.319 Hz, making this the fifth known millisecond accreting pulsar. There appears to be a significant sinusoidal modulation of the pulse frequency, at a period of 1.9 ± 0.3 hr, with a half- amplitude of 0.014 ± 0.002 Hz, although the short time baseline (3400 s) may contribute significant systematic uncertainties. Interpreted as an orbital Doppler modulation, the orbital period is most similar to the first such pulsar, SAX J1808.4-3658 (IAUC 6876, 6877). The following 2-10-keV x-ray fluxes (in mCrab, with uncertainties of approximately 0.1 mCrab) indicate that the source intensity is still increasing: May 27.5, 0.1; 31.5, 1.8; June 3.5, 7.1; 5.1, 10.5. Observations at other wavelengths are encouraged.