XY Arietis = H0253+193

IPs

AE Aqr
FO Aqr
XY Ari
V405 Aur
HT Cam
MU Cam
DW Cnc
BG CMi
V709 Cas
V1025 Cen
TV Col
TX Col
UU Col
V2306 Cyg
YY Dra
PQ Gem
DQ Her
EX Hya
NY Lup
V2400 Oph
GK Per
AO Psc
WX Pyx
V1223 Sgr
V1062 Tau
RX J2133

Candidates

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XY Arietis = H0253+193

A non-finding chart for XY Ari

SkyView image of the XY Ari region of the sky (see important notes). This image intentionally left blank, you are staring at the heart of the nearby molecular cloud, Lynds 1457.

Position:

Equatorial: 02^h56^m08.15^s, +19^d26^m33.8^s (J2000)
Galactic: l=159.25, b=-34.49

Finding Chart:

None published (not even in tne IR).

Brigntness:

Optical ; fx (2-10 keV)~1.9x10^(-11) ergs/cm/cm/s (ASCA)

Periods:

Orbital: 0.25270 d = 6.0648 hr= 21833.28s (X-ray eclipses, IR light curves).
Mid Eclipse = HJD 2447751.8398(1) + 0.25269664 (6) E
(Allan et al 1996b)
Spin: 0.00239d = 3.44 min = 206.3s, seen in X-rays.
No good spin ephemeris known?
Others:

Inclination:

80-84 (Hellier 1997)

Distance:

270+/-100 pc (Littlefair, Dhillon & Marsh 2001)

XY Ari is currently the only known deeply eclipsing, X-ray bright IP, unfortunately sitting right behind the molecular cloud Lynds 1457 (i.e., no optical counterpart). The egress timing study with XTE (Hellier 1997b) has placed tight constraints on the accretion region. The same capaign has also serendipitously caught XY Ari in an X-ray outburst (Hellier et al 1997). In quiescence, both poles appear to be visible, producing a double-humped spin pulse.