Open AccessX‐Ray and optical observations of XTE J0052−723: a transient Be/X‐ray pulsar in the Small Magellanic Cloud
Author(s) -
Laycock S.,
Corbet R. H. D.,
Coe M. J.,
Marshall F. E.,
Markwardt C.,
Edge W.
Publication year - 2003
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.1365-8711.2003.06179.x
Subject(s) - physics , astrophysics , pulsar , luminosity , observatory , telescope , small magellanic cloud , astronomy , stars , x ray pulsar , be star , galaxy
On 2000 December 27, during our regular Small Magellanic Cloud (SMC) monitoring programme using the Rossi X‐ray Timing Explorer ( RXTE ), strong pulsations were detected with a period of 4.78 s. Subsequent slew observations performed on January 9 and 13 across the field of view allowed localization of the pulsar's position to RA: 0 h 52 m 17 s , Dec.: 72°19′51″ (J2000). The outburst continued until January 24; seven PCA observations were obtained during this period, yielding a maximum X‐ray luminosity ∼10 38 erg s −1 . Following calculation of the pulsar position, optical observations of the RXTE error box were made on 2001 January 16 with the 1‐m telescope of the South African Astronomical Observatory (SAAO) while the source was still in X‐ray outburst. Candidate Be stars identified from their photometric colours were subsequently observed with the SAAO 1.9‐m telescope on 2001 November 7 to obtain spectra. Only one of the photometrically identified stars [MA93]537 showed prominent Hα emission, with a double peaked line‐profile ( EW =−43.3 ± 0.7 Å , separation v = 200 ± 15 km s −1 ), confirming the presence of a substantial circumstellar disc.