Parameters and Pulsation Constant of Cepheid

Round 1

Reviewer 1 Report

In the current state, this paper is not suitable for the publication of "particle" journal. 

  (1)The writing style of the article is also disappointing. It seems rare to use a complete sentence as the title of an article.The innovation and significance of this paper are not found in "Abstract".

  (2)The section of "Introduction" is not only particularly short, but also it does not present the research background, research objectives, research methods, research significance and the structure arrange of the article.

  (3) In the body of the paper,  the authors give a number of corresponding derivations and fitting based on previous empirical formulas on the mass, radius ,effective surface temperature, luminosity, absolute magnitude of Cepheids, but lacks the necessary physics，as well as  theoretical models. 

Author Response

Dear Sir/Madam,

I have taken into account all your comments. My answers for your comments are below:

1) The writing style of the article is also disappointing. It seems rare to use a complete sentence as the title of an article. The innovation and significance of this paper are not found in "Abstract".

I have shortened the title of my manuscript. Now the title is “Pulsation constant of Cepheid”. I have supplemented “Abstract” of my manuscript with the information about the innovation and the significance of my manuscript.

2) The section of "Introduction" is not only particularly short, but also it does not present the research background, research objectives, research methods, research significance and the structure arrange of the article.

I have supplemented “Introduction” of my manuscript with the information about the present research background, the research objectives, the research method, the research significance and the structure arrange of the manuscript.

3)   In the body of the paper, the authors give a number of corresponding derivations and fitting based on previous empirical formulas on the mass, radius, effective surface temperature, luminosity, absolute magnitude of Cepheids, but lacks the necessary physics, as well as theoretical models.

I have supplemented section 5 of my manuscript with the sentence: “The physical foundations and the theoretical models of a star pulsation as a stellar substance pulsation are presented in [13, 14, 93 - 96]”.

Thank you very much for your comments.

Best regards,

Sergei Sinitsyn

 

Author Response File: Author Response.pdf

Reviewer 2 Report

This is a good and interesting paper, concerning mainly the Cepheid it is pulsating? This paper is generally very well written, it is generally very well organized and it seems to me to be mathematically correct, thus this is a paper, which eventually deserves to be published. 

 

However, before it is ready for publication, I have a couple of questions and comments for the author of this paper: 

 

1. Why is Cepheid of type included two times in the title? For the non experts in the field: Is it because it is related to the next object?

 

2. From page 6 and in the rest of the paper, each equation have one or more $\pm$, but how are these uncertainties exactly determined? Are they purely observational or are they partly simulated? Or are they somewhat theoretical? This must be explained in general? 

 

3. What is really positive in this paper, is that the author makes a new standard for the number of citations in this paper. Almost hundred citations. Many scientists could learn of that?  

 

 

Further revision is necessary. 

 

Author Response

Dear Sir/Madam,

I have taken into account all your comments. My answers for your comments are below:

1) Why is Cepheid of type included two times in the title? For the non experts in the field: Is it because it is related to the next object?

I have shortened the title of my manuscript. Now the title is «Pulsation constant of Cepheid». I am preparing the next manuscript but about the variables of type RR Lirae. There will about 150 cited articles. For these variables the pulsation constant also very weakly depends on the pulsation period. 

2) From page 6 and in the rest of the paper, each equation have one or more $\pm$, but how are these uncertainties exactly determined? Are they purely observational or are they partly simulated? Or are they somewhat theoretical? This must be explained in general? 

Now in page 7 of my revised manuscript right after (11) I have pointed that error of this relation is three standard deviations of the sample mean. Further in page 8 right after (12) I have explained the nature of coefficient errors in all relations in the rest of my manuscript. 

Also, I have supplemented the abstract and the introduction of my manuscript with new information.

Thank you very much for your comments.

Best regards,

Sergei Sinitsyn

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

 

The revised manuscript has been made substantially but still does not meet the requirements of publication. A minor revision is suggested.

(1)Please brifely explain the main features of Cepheids of types δCephei and δScuti and shofar variables in the text.

(2) The authors stated that "This pulsation is triggered by the well-known effect of the local optical opacity of stellar substance using the usual pulsation of stellar substance" in Abstract and again stated that "This pulsation is triggered by the well-known effect of the local optical opacity of star's substance using the usual pulsation of star’s substance". Such statements are not specific and in-depth enough, because there is a dense and hot helium core inside a a Cepheid, and helium's self-propagation and periodic ionization and recombination lead to periodic changes in the optical opacity, which in turn lead to changes in temperature and radius of the star, and thus changing the star's brightness. 

(3)In Page 2, the author wrote that "These variable stars are in a wide range of evolutionary states, that is, from a normal dwarf to almost a red giant and a red supergiant. Moreover, these variable stars are in a wide range of masses, that is, about (1–10) solar masses", what cause a wide range of evolutionary states, as well as  a wide range of masses for these variable stars? Please give a simple explaination.

（4）In order to increase the appeal of the article, the author can expand as follows: There may be many factors affecting the formation path and evolution state of variable stars, such as parameters of metallicity and overshooting(Deng, et al. 2020,ApJ, 892,4, DOI:10.3847/1538-4357/ab76c4). In particular, convective overshoot is not only related to the formation and evolution of pulsating variable stars, but also associated with many important celestial bodies and extreme physical processes，such as massive pulsating variable stars(Shi et al. 2023 ApJS, 265 33, doi.10.3847/1538-4365/acba91), white dwarfs(Gao et al. 2023, AN,344,easna.20220112, doi.10.1002/asna.20220112), X-ray binaries(Deng, et al. 2021,ApJ,909,174, doi.10.3847/1538-4357/abe0b2), high-magnetic pulsars(Gao et al. 2016,MNRAS,456,55,doi.org/ 10.1093/mnras/stv2465;Gao et al.2017, ApJ,849,19, doi.10.3847/1538-4357/aa8f49) and supernova explosion.

(5)In Page 3, the authors wrote that“The dependence of BCV on log(Te) is weak when 3.64 ≤ log(Te) ≤3.93”. This sentence needs to be expanded appropriately as follows: This temperature (Te~ (4400 -8500)K) range happens to be the critical temperature region at which helium is completely ionized.

Best wishes

 Referee

Author Response

Dear Sir/Madam,

I have taken into account all your comments. My answers for your comments are below:

1) Please brifely explain the main features of Cepheids of types δCephei and δScuti and shofar variables in the text.

I have added the brief explanation of the main features of Cepheids of types δ Cephei and δ Scuti in the first paragraph on Page 2 of my revised manuscript. Unfortunately, I don’t know shofar variables. Moreover, I don’t find them in the site: https://ui.adsabs.harvard.edu.

2) The authors stated that "This pulsation is triggered by the well-known effect of the local optical opacity of stellar substance using the usual pulsation of stellar substance" in Abstract and again stated that "This pulsation is triggered by the well-known effect of the local optical opacity of star's substance using the usual pulsation of star’s substance". Such statements are not specific and in-depth enough, because there is a dense and hot helium core inside a Cepheid, and helium's self-propagation and periodic ionization and recombination lead to periodic changes in the optical opacity, which in turn lead to changes in temperature and radius of the star, and thus changing the star's brightness. 

In Abstract and Conclusions of my revised manuscript I have changed this sentence to “This pulsation is triggered by the well-known effects, for example, the local optical opacity of a star’s substance and overshooting, using the usual pulsation of a star’s substance”.

 

3) In Page 2, the author wrote that "These variable stars are in a wide range of evolutionary states, that is, from a normal dwarf to almost a red giant and a red supergiant. Moreover, these variable stars are in a wide range of masses, that is, about (1–10) solar masses", what cause a wide range of evolutionary states, as well as  a wide range of masses for these variable stars? Please give a simple explanation.

 

I have added the simple explanation of this cause in the second paragraph on Page 2 of my revised manuscript.

4) In order to increase the appeal of the article, the author can expand as follows: There may be many factors affecting the formation path and evolution state of variable stars, such as parameters of metallicity and overshooting (Deng, et al. 2020,ApJ, 892,4, DOI:10.3847/1538-4357/ab76c4). In particular, convective overshoot is not only related to the formation and evolution of pulsating variable stars, but also associated with many important celestial bodies and extreme physical processes，such as massive pulsating variable stars(Shi et al. 2023 ApJS, 265 33, doi.10.3847/1538-4365/acba91), white dwarfs(Gao et al. 2023, AN,344,easna.20220112, doi.10.1002/asna.20220112), X-ray binaries(Deng, et al. 2021,ApJ,909,174, doi.10.3847/1538-4357/abe0b2), high-magnetic pulsars(Gao et al. 2016,MNRAS,456,55,doi.org/ 10.1093/mnras/stv2465;Gao et al.2017, ApJ,849,19, doi.10.3847/1538-4357/aa8f49) and supernova explosion.

I have added this sentence before Conclusions on Page 13 of my revised manuscript. In this regards, I have added references 98 – 103.

 

5) In Page 3, the authors wrote that“The dependence of BCV on log(Te) is weak when 3.64 ≤ log(Te) ≤3.93”. This sentence needs to be expanded appropriately as follows: This temperature (Te~ (4400 -8500)K) range happens to be the critical temperature region at which helium is completely ionized.

I have added this sentence in the first paragraph on Page 4 of my revised manuscript.

 

 

I have changed the title of my manuscript a little, namely, from “Pulsation constant of Cepheid ” to “Parameters and pulsation constant of Cepheid”. The last title is more complete.

 

Also, I have checked orthography of my revised manuscript.

 

Thank you very much for your comments.

 

Best regards,

Sergei Sinitsyn

Reviewer 2 Report

The author of this paper, has answered all my questions and comments, which I raised in my first report, in a very satisfying way and he has improved his paper in many different ways, so I can now clearly recommend this paper for publication in this Journal. 

 

Author Response

Dear Sir/Madam,

 

Thank you very much for your comments and decision.

 

Best regards,

Sergei Sinitsyn