[vsolj-alert 427] XTE J1859+226 continues to rise; softens

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

XTE J1859+226 continues to rise; softens

　Ｘ線新星のXTE J1859+226がＸ線で引き続き増光中のようです。うーん、天気が
　悪いのが残念。スペクトル変化から、V518 Per (GRO J0422+32) のようなUSXT
　に分類されそうな気配です。

From: "Don A. Smith" <dasmith@space.mit.edu>
Subject: XTE J1859+226 continues to rise; softens
To: rhjellmi@aoc.nrao.edu (Robert M.)
Date: Fri, 15 Oct 1999 09:25:26 -0400 (EDT)
Cc: michiel@astro.uva.nl, rpf@astro.uva.nl, rudy@space.mit.edu (Rudy Wijnands),
        gehrels@lheavx.gsfc.nasa.gov, giommi@napa.sdc.asi.it,
        jem@head-cfa.harvard.edu, lewin@space.mit.edu (Walter H.G. Lewin),
        rr@space.mit.edu (Ron Remillard), shrader@grossc.gsfc.nasa.gov,
        stroh@pcasun1.gsfc.nasa.gov, swank@pcasun1.gsfc.nasa.gov,
        bmg@space.mit.edu (Bryan Gaensler), tkato@kusastro.kyoto-u.ac.jp,
        HARMON@SSLMOR.msfc.nasa.gov, chaswell@star.cpes.susx.ac.uk,
        ehm@space.mit.edu (Edward Morgan), Michael.McCollough@msfc.nasa.gov,
        p.charles1@physics.oxford.ac.uk, eiken@astrosun.tn.cornell.edu,
        srk@astro.caltech.edu, tavani@astro.columbia.edu,
        ewaltman@rsd.nrl.navy.mil, fghigo@cv3.cv.nrao.edu, rmw@as.arizona.edu,
        rhjellmi@zia.aoc.NRAO.EDU, mrupen@zia.aoc.NRAO.EDU,
        amiodusz@zia.aoc.NRAO.EDU, satr@cats.sao.ru, jgreiner@aip.de,
        mnowak@rocinante.colorado.edu, wheel@alla.as.utexas.edu,
        garcia@head-cfa.harvard.edu, RWH@physics.usyd.edu.au, res@jb.man.ac.uk,
        cjd@jb.man.ac.uk, amsr@jb.man.ac.uk, stg@jb.man.ac.uk,
        mirabel@discovery.saclay.cea.fr, rhjellmi@cv3.cv.nrao.edu,
        vdhawan@cv3.cv.nrao.edu, luisfr@astrosmo.unam.mx,
        ogley@discovery.saclay.cea.fr, guy@mrao.cam.ac.uk,
        jmarti@burriac.ujaen.es, Eric.Gerard@obspm.fr, S.Chaty@open.ac.uk

Greetings,

The most recent ASM observations of XTE J1859+226 indicate that the
source continues to brighten.  A cluster of four measurements around
Oct 15, 02:00 (UT) put the mean source intensity at 665+-12 mCrab
(2-12 keV).  After displaying no significant evolution during the
first day of outburst, the source spectrum began to soften, as
indicated by the hardness ratios.  For example, the ratio of counts in
the (5-12 keV) to the counts in the (3-5 keV) band fell from its mean
value of 1.6 for Oct 9 to a mean value of 0.8 for the four points this
morning.  A plot of this light curve and hardness ratio is posted at

http://xte.mit.edu/crossbox/xbox_011/main.html

Yours sincerely,
-- 
Dr. Don Smith			     The Rossi X-Ray Timing Explorer
dasmith@space.mit.edu        		http://vsnet.mit.edu/~dasmith/

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