SIMBAD references

S. Campana and M. Ravasio, Osservatorio Astronomico di Brera; and G. L. Israel and V. Mangano, Osservatorio Astronomico di Roma, report: "XMM-Newton observed the fourth millisecond pulsar XTE J1807-294 (IAUC 8080) during Mar. 22.581-22.778 UT. The source position is consistent with that determined with Chandra (IAUC 8095). The 0.5-10-keV x-ray countrate measured with EPIC-pn (in timing mode) was approximately 34.2 ± 0.1 count/s. No x-ray bursts were detected. Pulsations at 5.2459996(4) ms were detected with a pulsed fraction of 1.9 ± 0.3 percent (90-percent confidence level) in the band 0.5-10 keV. The orbital modulation instead was barely visible (probably due to the short exposure). No prominent emission or absorption lines are present in the RGS spectra. Analysis of the EPIC-MOS1 (full-frame mode) and EPIC-pn (timing mode) provided an absorbed (0.5-10 keV) source flux of 2 x 10**-10 erg cm**-2 s**-1. The source is still bright, and optical and infrared observations are encouraged in order to identify the optical counterpart."