Open AccessThe discovery of the optical/IR counterpart of the 12‐s transient X‐ray pulsar GS 0834−43
Author(s) -
Israel G. L.,
Covino S.,
Campana S.,
Polcaro V. F.,
Roche P.,
Stella L.,
Di Paola A.,
Lazzati D.,
Mereghetti S.,
Giallongo E.,
Fontana A.,
Verrecchia F.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03404.x
Subject(s) - physics , astrophysics , rosat , pulsar , be star , circumstellar envelope , x ray pulsar , infrared , star (game theory) , astronomy , x ray binary , line (geometry) , neutron star , stars , galaxy , geometry , mathematics
We report the discovery of the optical counterpart of the 12.3‐s transient X‐ray pulsar GS 0834−43. We reanalysed archival ROSAT PSPC observations of GS 0834−43, obtaining two new refined positions, ∼14 and ∼18 arcsec away from the previously published one, and a new spin period measurement. Based on these results we carried out optical and infrared (IR) follow‐up observations. Within the new error circles, we found a relatively faint ( V =20.1) early‐type reddened star ( V − R =2.24). The optical spectrum shows a strong H α emission line. The IR observations of the field confirm the presence of an IR excess for the H α ‐emitting star ( K ′=11.4, J − K ′=1.94), which is likely surrounded by a conspicuous circumstellar envelope. Spectroscopic and photometric data indicate a B0–2 V–IIIe spectral type star located at a distance of 3–5 kpc and confirm the Be‐star/X‐ray binary nature of GS 0834−43.