SUMMARY OF PROPOSAL 41049 DR FUMIAKI NAGASE ISAS KANAGAWA-KEN JAPAN 229 SAGAMIHARA-SHI 3-1-1 YOSHINODAI E-mail: NAGASE@ASTRO.ISAS.AC.JP Tel: 81-0427-51-3911 EXT.2611 Fax: 81-0427-59-4253 Medium: 4GBDAT Subject: X-RAY BINARIES Title: A NEW TRANSIENT WITH A RECURRENT OUTBURST PERIOD OF 241 DAYS Abstract: BATSE on CGRO found a new transient, GRO J1849-03, with a recurrent outburst period of 241 days. A few periodic transients have been known so far. Most of them are massive binaries with eccentric orbits and experience a flare at every periastron passage. GRO J1849-03 may be a binary pulsar with an unordinary long orbital period of 241 days, or a new kind of X-ray source like GRO J1655-40 (Nova Sco), which also shows periodic outbursts. In either (or neither) case, it would be an exciting target of Asca. We propose to observe the outburst of GRO J1849-03 "scheduled" on 14 Sept. 1996. The main purposes are positioning and identification of the source. This proposal should be accepted in AO-4 because the next chance for Asca to observe an outburst of GRO J1849-03 would be Sept. 1998. Co-Is: 1 TARO KOTANI ISAS JAPAN KOTANI@ASTRO.ISAS.AC.JP 81-0427-51-3986 2 HAJIME INOUE ISAS JAPAN 3 HIDEKI OZAWA ISAS JAPAN 4 TADAYASU DOTANI ISAS JAPAN 5 TAKASHI SONOBE FUJITSU JAPAN 6 SHUANG ZHANG USRA USA Target Name PRI RA Dec Time TC Off GIS SIS_Cts Obs ------------------- --- -------- -------- ---- -- --- --- ------- --- GRO J1849-03 2 282.2500 -3.3700 80 Y Y P 100.00000 2 REMARKS: 2 POINTINGS ARE REQUIRED TO SEARCH IN THE POSITION ERROR BOX. THE CENTERS OF EACH POINTING ARE (282.25, -3.17) AND (282.25, -3.57). Phase Critical Oservation: Epoch: 48412.0000 Period: 241.00000000 Min: 0.0000 Max: 0.0500