Delta-Scuti phase folded light curve equation

In summary, there is a concern about the up-down asymmetry in the data and whether it can be accurately modeled by an equation. The possibility of errors in the folding period and the approach to determining the equation is discussed.
  • #1
so_gr_lo
69
10
Homework Statement
Trying to fit a model to the phase folded light curve (v-band mag vs phase) from delta-scuti v-band data, tried to find an equation relating magnitude and phase for variable stars but can't find anything, is there a specific equation I can try to fit ? I've included the equation for asymmetric sinusoidal functions but not sure thats applicable
Relevant Equations
e.g. y=cos(x-1/2cos(x))

equation for calculating phase
[(t–to)/P]
data I'm trying to fit
1676928606971.png
 
Physics news on Phys.org
  • #2
The left-right asymmetry does not seem to be the major issue. It's the up-down asymmetry that bothers me. How does it get to be so sharp at the minima?
But I'm no astrophysicist, so maybe this happens. If so, any known explanation that would suggest an equation form?

If you don't care about the physics and just want some equation that models it I'll have a go.

The thickening approaching the peak is also curious. Is it possible that your folding period isn't quite right, e.g. if you double it do you see alternating behaviours over successive peaks?

Edit: given the raw data, and the desire to express it as ##y=A\sin(f(x))+B##, I would determine A and B by inspection and plot ##\arcsin(\frac{y-B}A)## against x. Of course, you will need to arrange that ##|\frac{y_i-B}A|\leq 1\forall i##, either by exaggerating A or by smoothing the data.

Edit 2: I just tried that by extracting a subset of the raw data from your chart. The result looked remarkably like the raw data. Reiterating led to a series of curves tending towards a sawtooth. Of course, one does have to be careful with an ambiguity arising from arcsin, but that does not seem to be the problem.
 
Last edited:

FAQ: Delta-Scuti phase folded light curve equation

What is a Delta-Scuti phase folded light curve equation?

A Delta-Scuti phase folded light curve equation is a mathematical representation used to describe the periodic brightness variations of Delta-Scuti stars. These stars exhibit pulsations that cause changes in their luminosity, which can be modeled and analyzed using this equation.

Why are Delta-Scuti stars important to study?

Delta-Scuti stars are important because their pulsations provide insights into stellar structure and evolution. By studying these stars, scientists can learn about the internal processes and characteristics of stars, which helps improve our understanding of stellar dynamics and the broader mechanisms at play in the universe.

How is the phase folding process applied in analyzing Delta-Scuti stars?

Phase folding is a technique used to combine multiple observations of a star's brightness over time into a single, coherent light curve. This is done by plotting the observed brightness against the star's phase, which is a measure of its pulsation cycle. This process helps to reveal the periodic nature of the brightness variations and simplifies the analysis of the star's pulsation patterns.

What information can be derived from the light curve of a Delta-Scuti star?

The light curve of a Delta-Scuti star provides information about the star's pulsation periods, amplitudes, and modes. By analyzing these aspects, scientists can infer the star's physical properties, such as its mass, radius, and internal structure. Additionally, the light curve can reveal the presence of multiple pulsation modes, which are critical for understanding the star's behavior and evolution.

What are the challenges in modeling Delta-Scuti phase folded light curves?

Modeling Delta-Scuti phase folded light curves can be challenging due to the complexity of the pulsation patterns, which often involve multiple frequencies and modes. Additionally, observational noise and gaps in data can complicate the analysis. Advanced mathematical techniques and high-quality, continuous data are required to accurately model and interpret these light curves.

Back
Top