EXO 041604-5504.9

D. Alloin and D. Pelat, Meudon Observatory; and S. D'Odorico, European Southern Observatory, write: "A new, soft x-ray source at high galactic latitude (R.A. = 4h16m03s5 +/- 1s5, Decl. = -55deg04'55" +/- 20", equinox 1950.0) has been discovered from EXOSAT low-energy observations. The x-ray flux in the range 0.04-2 keV is variable and changes by 70 percent on a timescale of 1 month. We find channel- multiplier array (+ thin Lexan) count rates between 0.5-0.85 x 10**2 cts/s, corresponding to ~ 0.14-0.23 mCrab. The source is detected at a 6-sigma level. An optical counterpart can be found on the ESO B Survey as a star of B ~ 16. Quick image-dissector-scanner and CCD spectra of this object were obtained on May 1 and 14 at ESO with a spectral resolution ~ 1.3 nm; they show strong Balmer absorption features and a weak Ca-II K line, suggesting an A5-type star. From an echelle spectrum taken on Apr. 3 the H-beta line-center provides a heliocentric velocity of 20 +/- 8 km/s."