SUMMARY OF PROPOSAL 71044

DR. TARO KOTANI
KOTANI@RIKEN.GO.JP

RIKEN
HIROSAWA 2-1
WAKO
SAITAMA JAPAN 351-0198
Tel: 048 462 1111 X3229 Fax: 048 462 4640
Medium: 4GBDAT
Subject: X-RAY BINARIES

XTE J1748-288: SECOND SS 433?


ABSTRACT

The new X-ray nova XTE J1748-288 was discovered in June 1998. VLA observations of the radio counterpart revealed proper motions of >20 mas/day, which would correspond to a speed of > 0.1 c assuming a distance of 10 kpc. Although 70 days have passed since the onset of the flare, the source is still as bright as 100 mJy at 2 GHz. Thus this source is evidently a jet system, probably similar to SS 433, which has a persistent jet of 0.26 c. With ASCA, it is possible to detect Doppler-shifted lines from jets, and to determine jet parameters such as velocity, inclination, and temperature. However, ASCA has never observed any jet system at the very moment of jet ejection except for SS 433. Therefore, it is strongly desired to observe the new jet XTE J1748-288 with ASCA as soon as possible.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
TOMOHARU OKARIKENJAPAN
NOBUYUKI KAWAIRIKENJAPAN
MASAAKI NAMIKIRIKENJAPAN
HITOSHI NEGORORIKENJAPAN
MASARU MATSUOKARIKENJAPAN
YOSHIHIRO UEDAISASJAPAN
FUMIAKI NAGASEISASJAPAN

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)XTE J1748-288
C
267.0213-28.4738
40 ks
N
Y
P
1.00000
1

TARGET 1

SINCE THIS SOURCE IS UNDERGOING AN OUTBURST, IT SHOULD BE OBSERVED AS SOON AS POSSIBLE.