2018A&A...615A..44R


Query : 2018A&A...615A..44R

2018A&A...615A..44R - Astronomy and Astrophysics, volume 615A, 44-44 (2018/7-1)

Intriguing X-ray and optical variations of the γ Cassiopeiae analog HD 45314.

RAUW G., NAZE Y., SMITH M.A., MIROSHNICHENKO A.S., GUARRO FLO J., CAMPOS F., PRENDERGAST P., DANFORD S., GONZALEZ-PEREZ J.N., HEMPELMANN A., MITTAG M., SCHMITT J.H.M.M., SCHRODER K.-P. and ZHARIKOV S.V.

Abstract (from CDS):


Context. A growing number of Be and Oe stars, named the γ Cas stars, are known for their unusually hard and intense X-ray emission. This emission could either trace accretion by a compact companion or magnetic interaction between the star and its decretion disk.
Aims. To test these scenarios, we carried out a detailed optical monitoring of HD 45314, the hottest member of the class of γ Cas stars, along with dedicated X-ray observations on specific dates.
Methods. High-resolution optical spectra were taken to monitor the emission lines formed in the disk, while X-ray spectroscopy was obtained at epochs when the optical spectrum of the Oe star was displaying peculiar properties.
Results. Over the last four years, HD 45314 has entered a phase of spectacular variations. The optical emission lines have undergone important morphology and intensity changes including transitions between single- and multiple-peaked emission lines as well as shell events, and phases of (partial) disk dissipation. Photometric variations are found to be anti-correlated with the equivalent width of the Hα emission. Whilst the star preserved its hard and bright X-ray emission during the shell phase, the X-ray spectrum during the phase of (partial) disk dissipation was significantly softer and weaker.
Conclusions. The observed behaviour of HD 45314 suggests a direct association between the level of X-ray emission and the amount of material simultaneously present in the Oe disk as expected in the magnetic star-disk interaction scenario.

Abstract Copyright: © ESO 2018

Journal keyword(s): stars: emission-line, Be - stars: individual: HD 45314 - X-rays: stars

Simbad objects: 16

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Number of rows : 16
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9859 1
2 HD 5314 * 00 55 26.3920 +40 22 56.849   8.26 8.08     A2 14 1
3 * gam Cas Be* 00 56 42.5317 +60 43 00.265 1.18 2.29 2.39 2.32 2.40 B0.5IVpe 1156 2
4 * 28 Tau Be* 03 49 11.2175463444 +24 08 12.172181348 4.73 5.01 5.09   5.08 B8Vne 443 0
5 V* X Per HXB 03 55 23.0778791365 +31 02 45.045745259 6.090 6.840 6.720     O9.5III 923 0
6 * mu. Gem LP* 06 22 57.62686 +22 30 48.8979 6.37 4.51 2.87 1.30 -0.08 M3IIIab 370 1
7 HD 45314 Be* 06 27 15.7780829067 +14 53 21.219330074 5.91 6.79 6.64     O9:npe 158 0
8 HD 49330 Be* 06 47 57.2678873802 +00 46 34.039802717 8.45 9.14 8.95     Bnn(e) 79 0
9 HD 60848 Be* 07 37 05.7328585099 +16 54 15.303398878 5.55 6.67 6.87     O8:V:pe 132 0
10 HD 119682 Be* 13 46 32.5707617771 -62 55 24.153203600 7.26 7.978 7.901 8.72   B0Ve 55 0
11 HD 120678 Em* 13 52 56.4133085414 -62 43 14.259143108 7.04 9.45 8.20 9.02   O9.5Ve 68 1
12 * del Sco SB* 16 00 20.00528 -22 37 18.1431 1.30 2.20 2.32 2.36 2.49 B0.3IV 703 0
13 HD 157832 Be* 17 27 54.8113464489 -47 01 34.399141463 5.81 6.636 6.663     B2ne 57 1
14 * alf Aql dS* 19 50 46.99855 +08 52 05.9563 1.07 0.98 0.76 0.62 0.49 A7Vn 834 0
15 * f01 Cyg Be* 20 59 49.5516391039 +47 31 15.378902421 3.77 4.71 4.75 4.62 4.63 B1.5Vnne 472 0
16 * pi. Aqr Be* 22 25 16.6228499 +01 22 38.634579 3.64 4.60 4.64 4.48 4.48 B1III-IVe 390 0

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2021.08.03-02:45:50

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