scholarly journals The light curve of type I Supernovae

1980 ◽  
Author(s):  
S. A. Colgate ◽  
Albert G. Petschek ◽  
John T. Kriese
Keyword(s):  
1999 ◽  
Vol 117 (3) ◽  
pp. 1175-1184 ◽  
Author(s):  
Nicholas B. Suntzeff ◽  
M. M. Phillips ◽  
R. Covarrubias ◽  
M. Navarrete ◽  
J. J. Pérez ◽  
...  

2020 ◽  
Vol 500 (3) ◽  
pp. 2958-2968
Author(s):  
Grant Merz ◽  
Zach Meisel

ABSTRACT The thermal structure of accreting neutron stars is affected by the presence of urca nuclei in the neutron star crust. Nuclear isobars harbouring urca nuclides can be produced in the ashes of Type I X-ray bursts, but the details of their production have not yet been explored. Using the code MESA, we investigate urca nuclide production in a one-dimensional model of Type I X-ray bursts using astrophysical conditions thought to resemble the source GS 1826-24. We find that high-mass (A ≥ 55) urca nuclei are primarily produced late in the X-ray burst, during hydrogen-burning freeze-out that corresponds to the tail of the burst light curve. The ∼0.4–0.6 GK temperature relevant for the nucleosynthesis of these urca nuclides is much lower than the ∼1 GK temperature most relevant for X-ray burst light curve impacts by nuclear reaction rates involving high-mass nuclides. The latter temperature is often assumed for nuclear physics studies. Therefore, our findings alter the excitation energy range of interest in compound nuclei for nuclear physics studies of urca nuclide production. We demonstrate that for some cases this will need to be considered in planning for nuclear physics experiments. Additionally, we show that the lower temperature range for urca nuclide production explains why variations of some nuclear reaction rates in model calculations impacts the burst light curve but not local features of the burst ashes.


2019 ◽  
Vol 16 (11) ◽  
pp. 1950177 ◽  
Author(s):  
H. Hossienkhani ◽  
N. Azimi ◽  
Z. Zarei

Recent observers have shown that an anisotropy cosmic expansion may exist. In this work, we study the effects of low anisotropy with Bianchi type I model using the current observational data, which includes the supernova Legacy Survey (SNLS) sample of 238 SN events ([Formula: see text]) and 1048 Pantheon sample confirmed type Ia supernova (SNIa) covering the redshift range [Formula: see text]. Assuming an anisotropic universe, we use the two parametrizations of the dark energy equation-of-state, such as the [Formula: see text] (PA) and [Formula: see text] (PB), and then we fit the SNIa light-curve parameters and free cosmological parameters, simultaneously employing maximum likelihood estimation method. When combining the Baryon Acoustic Oscillations (BAO) and the observational Hubble data (OHD) measurements with the SNLS SN sample, we find [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PA model and [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PB model. When combining also Pantheon data, we obtain [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PA model and [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PB model. The analysis shows that by considering the anisotropy effects, it leads to more best-fit parameters in [Formula: see text]CDM model with the current observational data.


2018 ◽  
Author(s):  
Salvador Barquin

Discovery of a new binary star system (GSC 03905-01870 = USNO-B1.0 1431-0327922 = UCAC4 716-059522) in the Draco constellation is presented. It was discovered during a search for previously unreported eclipsing binary stars through the ASAS-SN database. The shape of the light curve and its characteristics (period of 0.428988±0.000001 d, amplitude of 0.34±0.02 V Mag, primary minimum epoch HJD 2457994.2756±0.0002) indicates that the new variable star is an eclipsing binary of W Ursae Majoris type. I registered this variable star in The International Variable Star Index (VSX), its AAVSO UID is 000-BMP-891.


2017 ◽  
Vol 851 (1) ◽  
pp. L14 ◽  
Author(s):  
J. Craig Wheeler ◽  
Emmanouil Chatzopoulos ◽  
Jozsef Vinkó ◽  
Richard Tuminello

1987 ◽  
Vol 93 ◽  
pp. 413-417
Author(s):  
R. Lopez ◽  
J. Isern ◽  
J. Labay ◽  
R. Canal

AbstractWe present models for Type I supernova light curves based on the explosion of partially solid white dwarfs in close binary systems. Studies of such explosions show that they leave bound remnants of different size. Our results reproduce quite well the maximun luminosities, the expansion velocities and the shape of the light curve. As the two basic papameters that govern the light curve, the ejected mass and the mass of 56Ni produced, are variable our models reproduce the slow and fast subclasses of “classical” Type I supernovae.


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