The OmegaWhite survey for short-period variable stars – VII. High amplitude short-period blue variables
The OmegaWhite survey for short-period variable stars – VII. High amplitude short-period blue variables
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OmegaWhite 对短周期变星的巡天 – VII。
DOI：
10.1093/mnras/stac1000
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发表时间：
2022
影响因子：
4.8
通讯作者：
Irrgang, Andreas
中科院分区：
文献类型：
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作者：
Ramsay, Gavin;Woudt, Patrick A.;Kupfer, Thomas;van Roestel, Jan;Paterson, Kerry;Warner, Brian;Buckley, David A. H.;Groot, Paul J.;Heber, Ulrich;Irrgang, Andreas
蓝色大振幅脉冲星（BLAPs）是一类相对较新的蓝色变星，它们的光变曲线具有周期性变化，周期短于几十分钟，振幅超过10%。我们报告了在使用ESO的VST进行的OmegaWhite调查中发现的9颗蓝色变星，这表明，在7-37分钟的范围内的周期性调制和幅度在0.11-0.28马格的范围内。我们已经获得了一系列的后续测光和光谱观测主要使用SALT和望远镜在SAAO。我们发现四颗恒星，我们确定为BLAPs，其中一个是以前已知的。其中一颗星星，OW J 0820 -3301，似乎是V361 Hya类脉动恒星的成员，在空间上接近一个扩展的星云。另一颗星星OW J1819-2729，具有类似sdAV的特征。相比之下，OW J 0815 -3421是一颗包含一颗sdB和一颗白色矮星的联星星星，轨道周期为73.7分钟，是六颗轨道周期小于80分钟的白色矮星-sdB联星之一。最后，四个候选BLAP的高节奏测光显示的功能，我们比较在更长的周期造父变星看到的缺口状功能。
Blue Large-Amplitude Pulsators (BLAPs) are a relatively new class of blue variable stars showing periodic variations in their light curves with periods shorter than a few tens of minutes and amplitudes of more than 10 per cent. We report nine blue variable stars identified in the OmegaWhite survey conducted using ESO’s VST, which shows a periodic modulation in the range 7–37 min and an amplitude in the range 0.11–0.28 mag. We have obtained a series of followup photometric and spectroscopic observations made primarily using SALT and telescopes at SAAO. We find four stars which we identify as BLAPs, one of which was previously known. One star, OW J0820–3301, appears to be a member of the V361 Hya class of pulsating stars and is spatially close to an extended nebula. One further star, OW J1819–2729, has characteristics similar to the sdAV pulsators. In contrast, OW J0815–3421 is a binary star containing an sdB and a white dwarf with an orbital period of 73.7 min, making it only one of six white dwarf-sdB binaries with an orbital period shorter than 80 min. Finally, high cadence photometry of four of the candidate BLAPs show features that we compare with notch-like features seen in the much longer period Cepheid pulsators.