Asteroseismic investigation of 44 Tau, a slowly rotating delta Scuti star

Kirbiyik, H
Civelek, R
Kiziloglu, N
Evolutionary model calculations of 44 Tau, a delta-Scuti star, have been carried out. The star in question is a slow rotator (vsini = 6.8 kms(-1)). However small it may be, the effect of rotation on the oscillation properties of the star was thought to be worth of studying. Models were evolved with uniform rotation. Radial and non-radial adiabatic oscillation frequencies were calculated. In determining oscillation frequencies rotation has been treated as a perturbation. First order effect has been considered. The possible rotational splittings, due to two rotation speeds, have been calculated.


Radial and nonradial oscillations of 44 Tauri
Civelek, R; Kiziloglu, N; Kirbiyik, H (American Astronomical Society, 2001-10-01)
Evolutionary stellar models of 44 Tauri, a multiperiodic delta Scuti star, have been developed theoretically and compared with earlier observational reports. The models depict 44 Tau at the hydrogen-shell-burning stage, when it is in radiative equilibrium with a very thin surface convective layer. Using the models, we performed calculations to obtain radial and nonradial adiabatic oscillation frequencies, and the equations were treated linearly. The results showed that the radial fundamental (6.899 cycles d...
Chandra observation of the shell of Nova Persei 1901 (GK Persei): Detection of localized nonthermal X-ray emission from a miniature supernova remnant
Balman, Şölen (IOP Publishing, 2005-07-10)
I present data on the shell of classical Nova Persei (1901) obtained by the Advanced CCD Imaging Spectrometer S3 detector on board the Chandra X-Ray Observatory. The X-ray nebula is affected mostly by the complex interstellar medium around the nova and has not developed a regular shell. The X-ray nebula is lumpy and asymmetric, with the bulk of the emission coming from the southwestern quadrant. The brightest X-ray emission is detected as an arc that covers the region from the west to the south of the centr...
Pregalactic-primordial low-mass stars
Kızıloğlu, Nilgün Gülşan; Eryurt, Dilhan Ezer (Springer Science and Business Media LLC, 1987-8)
The Main-Sequence positions as well as the evolutionary behavior of Population III stars up to an evolution age of 2×1010 yr, taking this time as the age of the Universe, have been investigated in the mass range 0.2 and 0.8M ⊙. While Population III stars with masses greater than 0.3M ⊙ develop a radiative core during the approach to the Main Sequence, stars with masses smaller than 0.3M ⊙ reach the Main Sequence as a wholly convective stars. Population III stars with masses greater than 0.5M ⊙ show a bright...
Upper limits to the SN1006 multi-TeV gamma-ray flux from HESS observations
Aharonian, F; et. al. (EDP Sciences, 2005-07-01)
Observations of the shell-type supernova remnant SN1006 have been carried out with the HESS system of Cherenkov telescopes during 2003 (18.2 h with two operating telescopes) and 2004 (6.3 h with all four telescopes). No evidence for TeV gamma-ray emission from any compact or extended region associated with the remnant is seen and resulting upper limits at the 99.9% confidence level are up to a factor 10 lower than previously-published fluxes from CANGAROO. For SN1006 at its current epoch of evolution we def...
Very high energy gamma rays from the composite SNR G0.9+0.1
Aharonian, F; et. al. (EDP Sciences, 2005-03-01)
Very high energy (> 100 GeV) gamma-ray emission has been detected for the first time from the composite supernova remnant G0.9+ 0.1 using the HESS instrument. The source is detected with a significance of approximate to 13sigma, and a photon flux above 200 GeV of ( 5.7 +/- 0.7(stat) +/- 1.2(sys)) x 10(-12) cm(-2) s(-1), making it one of the weakest sources ever detected at TeV energies. The photon spectrum is compatible with a power law ( dN/dE proportional to E-Gamma) with photon index Gamma = 2.40 +/- 0.1...
Citation Formats
H. Kirbiyik, R. Civelek, and N. Kiziloglu, “Asteroseismic investigation of 44 Tau, a slowly rotating delta Scuti star,” ASTROPHYSICS AND SPACE SCIENCE, pp. 305–313, 2003, Accessed: 00, 2020. [Online]. Available: