scholarly journals High Time Resolution Spectroscopic Observations of Stellar Shock Waves

1988 ◽  
Vol 132 ◽  
pp. 205-208
Author(s):  
P. L. Cottrell ◽  
W. A. Lawson ◽  
S. M. Smith

An absorption line–splitting phenomenon, first reported by Cottrell and Lambert (1982a), has been shown to occur at about maximum light in the semi-regular pulsations of the R Coronae Borealis (RCB) star, RY Sgr (Lawson 1986). This has been interpreted as a shock wave propagating through the photospheric layers (Lawson and Cottrell 1986). We present spectroscopic observations of this star, taken to coincide with this line–splitting event. A sequence obtained during 1986 October revealed that this event extended over about 6 days (out of a period of about 40 days) and began at about the bluest B-V. This colour maximum, which corresponds to maximum photospheric temperatures and minimum radius, leads the V maximum by about 6 days.

1993 ◽  
Vol 139 ◽  
pp. 428-428
Author(s):  
Michael D. Joner ◽  
John M. Powell

AbstractCY Aquarii is a Population II dwarf Cepheid that has been observed on a regular basis since 1930. We present evidence from unpublished times of maximum light from Brigham Young University observations secured in the mid-1970s to the present that indicate that the period of CY Aqr has changed in a discontinuous manner. Furthermore, we find that the period has changed significantly since the epoch of the last published investigation (1988). Finally, contrary to some past claims, examination of our high time resolution light curves yields no indication of multi-periodic pulsation in CY Aqr.


1994 ◽  
Vol 144 ◽  
pp. 431-434
Author(s):  
M. Minarovjech ◽  
M. Rybanský

AbstractThis paper deals with a possibility to use the ground-based method of observation in order to solve basic problems connected with the solar corona research. Namely:1.heating of the solar corona2.course of the global cycle in the corona3.rotation of the solar corona and development of active regions.There is stressed a possibility of high-time resolution of the coronal line photometer at Lomnický Peak coronal station, and use of the latter to obtain crucial observations.


2010 ◽  
Vol 180 (4) ◽  
pp. 424 ◽  
Author(s):  
G.M. Beskin ◽  
S.V. Karpov ◽  
S.F. Bondar ◽  
V.L. Plokhotnichenko ◽  
A. Guarnieri ◽  
...  

APL Photonics ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 036114
Author(s):  
J. Chang ◽  
J. W. N. Los ◽  
J. O. Tenorio-Pearl ◽  
N. Noordzij ◽  
R. Gourgues ◽  
...  

2021 ◽  
Vol 772 ◽  
pp. 144766
Author(s):  
Lingling Lv ◽  
Yingjun Chen ◽  
Yong Han ◽  
Min Cui ◽  
Peng Wei ◽  
...  

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