1:45 PM - 3:15 PM
[O11-P08] Relationship between Luminosity and Temperature due to the Nova Eruption of the T Coronae Borialis ( T CrB )
Keywords:T Coronae Borealis , Nova eruption
[Background and purpose]
TCrB is a star in which two stars are spinning. There, gas is flowing out of this huge star called red giant star. The gas flows into a small star called a white dwarf star.
And eventually when this star becomes unable to withstand it , the star cause an eruption. At this time, what only the surface erupt is called a nova eruption . The amount of this gas is determined for each star, and every time it reaches that amount, the recurrent nova will erupt.TCrB is 3000 light years away from the Earth. And in normal state, it changes the luminosity from 0.3 to 0.6. It is known as the recurrent nova which repeats nova eruption.
About it, last eruption was in 1964 and before the last eruption was in 1866. So it is said that the eruption period is about 78 years.
Also, the sign of the next eruption , dimming and brightening was observed in 2023. From the period of the eruption, records of the last eruption and sign of the next eruption, we found that it might erupt between February to September in 2024.
This project attempts to make the relarionship clear between its brightening and change in temperature caused by the nova eruption,capturing images.
[Hypothesis]
TCrB in normal state is red. However, as the luminosity changes due to the eruption, the color turns blue.
[Experimental method]
We are trying to absorb the luminosity and color of the eruption before brightening, when brightening, at the peak of brightening, and when dimming.
To compare the luminosity, we mainly use a smart telescope "Seestar s50". The luminosity can be calculated by the Pogson's equation, with accurately measured luminosity of stars in a normal state.
Also, in order to make the calculation more acculate, we are using the SUBARU Image Processor "Makali'i".
Color comparison will be made by our visual observation and images captured by Seestar s50.
Through these multicolor photometry we are going to commute B-V , color index .Strictly speaking, the "sG magnitude" cannot be treated in the same way as the V magnitude, the standard system of astronomy.
However, similar to the wavelength characteristics of the G-plane of the digital camera, it is relatively similar to the standard system, so here it is treated as a simple color index.
[Result]
The eruption has not been caused at the moment . So we cannot make the relarionship clear between its brightening and change in temperature caused by the nova eruption .However, we have continued to observe TCrB.
The values of observation are like these. As for the luminosity,It is being slightly dimmed. And the magnitude of B-G , simplified color index has slightly gotten smaller.
[Interpretation]
In the last eruption, after a period of no change in luminosity, it was dimming about a year before the eruption happened. From the current range of changes in luminosity , we think that TCrB is in the period of the sign of the eruption like here. In addition, from the change in color index , we think that the color of TCrB turns blue and it is getting hotter.
[Conclusion]
We haven't been able to test the hypothesis because there hasn't been an eruption yet. So we are going to continue measuring the luminosity and calculating the color index
Moreover,There is a possibility that the eruption will not happen while we are conducting this research as high school students, but we are going to carry out activities such as predicting the time of the eruption .
[Reference]
*1The Japan variable star society [2024].Let's monitor the eruption of the recurrent nova ,T Coronae borealis!
*2 B. E. Schaefer (Louisiana State Univ.), B. Kloppenborg (AAVSO), E. O. Waagen (AAVSO), and the AAVSO observers[2023 ]. Announcing T CrB pre-eruption dip . AAVSO
*3 Bradley E. Schaefer [2010] . COMPREHENSIVE PHOTOMETRIC HISTORIES OF ALL KNOWN GALACTIC RECURRENT NOVA
*4 Bradley E. Schaefer [2023] .The B & V light curves for recurrent nova T CrB from 1842-2022, the unique pre- and post-eruption high-states, the complex period changes, and the upcoming eruption in 2025.5 ±1.3
TCrB is a star in which two stars are spinning. There, gas is flowing out of this huge star called red giant star. The gas flows into a small star called a white dwarf star.
And eventually when this star becomes unable to withstand it , the star cause an eruption. At this time, what only the surface erupt is called a nova eruption . The amount of this gas is determined for each star, and every time it reaches that amount, the recurrent nova will erupt.TCrB is 3000 light years away from the Earth. And in normal state, it changes the luminosity from 0.3 to 0.6. It is known as the recurrent nova which repeats nova eruption.
About it, last eruption was in 1964 and before the last eruption was in 1866. So it is said that the eruption period is about 78 years.
Also, the sign of the next eruption , dimming and brightening was observed in 2023. From the period of the eruption, records of the last eruption and sign of the next eruption, we found that it might erupt between February to September in 2024.
This project attempts to make the relarionship clear between its brightening and change in temperature caused by the nova eruption,capturing images.
[Hypothesis]
TCrB in normal state is red. However, as the luminosity changes due to the eruption, the color turns blue.
[Experimental method]
We are trying to absorb the luminosity and color of the eruption before brightening, when brightening, at the peak of brightening, and when dimming.
To compare the luminosity, we mainly use a smart telescope "Seestar s50". The luminosity can be calculated by the Pogson's equation, with accurately measured luminosity of stars in a normal state.
Also, in order to make the calculation more acculate, we are using the SUBARU Image Processor "Makali'i".
Color comparison will be made by our visual observation and images captured by Seestar s50.
Through these multicolor photometry we are going to commute B-V , color index .Strictly speaking, the "sG magnitude" cannot be treated in the same way as the V magnitude, the standard system of astronomy.
However, similar to the wavelength characteristics of the G-plane of the digital camera, it is relatively similar to the standard system, so here it is treated as a simple color index.
[Result]
The eruption has not been caused at the moment . So we cannot make the relarionship clear between its brightening and change in temperature caused by the nova eruption .However, we have continued to observe TCrB.
The values of observation are like these. As for the luminosity,It is being slightly dimmed. And the magnitude of B-G , simplified color index has slightly gotten smaller.
[Interpretation]
In the last eruption, after a period of no change in luminosity, it was dimming about a year before the eruption happened. From the current range of changes in luminosity , we think that TCrB is in the period of the sign of the eruption like here. In addition, from the change in color index , we think that the color of TCrB turns blue and it is getting hotter.
[Conclusion]
We haven't been able to test the hypothesis because there hasn't been an eruption yet. So we are going to continue measuring the luminosity and calculating the color index
Moreover,There is a possibility that the eruption will not happen while we are conducting this research as high school students, but we are going to carry out activities such as predicting the time of the eruption .
[Reference]
*1The Japan variable star society [2024].Let's monitor the eruption of the recurrent nova ,T Coronae borealis!
*2 B. E. Schaefer (Louisiana State Univ.), B. Kloppenborg (AAVSO), E. O. Waagen (AAVSO), and the AAVSO observers[2023 ]. Announcing T CrB pre-eruption dip . AAVSO
*3 Bradley E. Schaefer [2010] . COMPREHENSIVE PHOTOMETRIC HISTORIES OF ALL KNOWN GALACTIC RECURRENT NOVA
*4 Bradley E. Schaefer [2023] .The B & V light curves for recurrent nova T CrB from 1842-2022, the unique pre- and post-eruption high-states, the complex period changes, and the upcoming eruption in 2025.5 ±1.3