View source for A0535+26

[[Category:Accreting X-ray Pulsars]]


'''This page is still edited'''


= System Overview =

{| class="wikitable"
|P<sub>orb</sub> 
| 111.1 
| days 
| Finger et al. 2006 
|- 
|P<sub>spin</sub> 
| 103.4 
| s 
| Rosenberg et al. 1975, Makino et al. 1989, ... 
|- 
|B 
| 4x10<sup>12</sup> 
| G 
| Kendziorra et al. 1994 
|- 
|a sin i 
| 267 
| lt-sec 
| Finger et al. 2006 
|- 
|eccentricity 
| 0.47 
| 
| Finger et al. 2006 
|- 
|ω 
| 130 
|degree 
| Finger et al. 2006 
|- 
|Τ<sub>periastron</sub> 
| 53613.0 
| MJD 
| Finger et al. 2006 
|- 
|distance 
| 2 
| kpc 
| Steele et al. 1994 
|}

= Optical companion =

HDE 245770, spectral class: O9.7IIIe (Giangrande et al. 1980), B0 IIIe (Steele et al. 1998) <br />

{| class="wikitable"
|M 
| 14 / 20 / 26 
| M<sub>⊙</sub> 
| de Loore et al. 1984 / Coe et al. 2006 / Haigh et al. 2004 
|- 
|R 
| 14 
| R<sub>⊙</sub> 
|de Loore et al. 1984 
|- 
|Mdot 
| 10<sup>-8</sup> 
| M<sub>⊙</sub> 
|de Loore et al. 1984 
|- 
|T<sub>eff</sub> 
| 26000-28000 
| K 
| Giovannelli & Graziati 1992 
|- 
|L 
| 0.7 x 10<sup>5</sup> 
| L<sub>⊙</sub> 
| Giovannelli & Graziati 1992 
|}
= Description =

=== Pulse period and pulse profiles ===

* pulse shape and intensity are highly variable (Frontera et al. 1985) 
* lower energies several, irregularly spaced maxima observed (bradt et al. 1976)
* double-peaked pulse profiles above 20 keV
* asymmetric main and more symmetric secondary peak (Kendziorra et al. 1994)
* pulsed fraction increases with energy (Frontera et al. 1985, Kendziorra et al. 1994)

=== Spectrum ===

* hard power law with index 0.8-1.1 with exponential cutoff (Ricketts et al. 1975, Kendziorra et al. 1994) 
* 2 cyclotron lines at about 50, 100 keV
* Pulse phase analysis: main pulse spectrum harder than secondary pulse (Kendziorra et al. 1994)