Studies of Magnetic Chemically Peculiar Stars Using the 6-m Telescope at SAO RAS

Round 1

Reviewer 1 Report

The paper is well written and very thorough. I just have one comment:

Page 3 , line 123: Antonia Maury published her findings in 1897 and not 1899.

Author Response

Author Response File: Author Response.pdf

Reviewer 2 Report

The text of the manuscript Magnetic Chemically Peculiar Stars by I. Romanyuk
was not carefully read by the author before submission.
I have a number of comments and requests that need to be addressed before the manuscript can be
suggested for acceptance:

- The title of the paper is misleading. In fact, the content is mostly related to an overview of the work
carried out with the 6-m telescope. I suggest as a title:
Studies of magnetic chemically peculiar stars using the 6-m telescope at SAO

- Abstract: The sentence on the dynamo mechanism should be removed - the author does not
present in this work any theoretical evidence that the dynamo mechanism cannot be considered
for the field origin at any stage of the stellar evolution.

- Sect. 2:
line 82: remove the word Even in the sentence "Even Babcock discovered..."
line 89: this should not be a new paragraph.
line 92: explain the meaning of oppositely-polarized in a circle.
line 95: who found the average shift, the author or Babcock?
line 96: the spectra are not DETECTED simultaneously...
line 108: this should be a new paragraph.

Sect. 2.2:
line 114: significant increase in what? In the abundance?
line 117: give the reference for the statement that about a quarter of the chemically peculiar
  stars have stable magnetic fields. It is not correct, unless the author refers to a very old study.
line 122: give the full name of the HD catalog.
line 129: reformulate "variations in brightness ... allow to find.. vsini..." - this is not correct.
line 136: it is necessary to mention the merger scenario - there is growing evidence that interaction
  in binaries or multiple stars plays a role in the generation of magnetic fields (see e.g. Mathys 2017).
line 169: the spectral resolution of different spectropolarimeters should be mentioned. Why is HARPS not
  mentioned?
line 180: the low resolution of MSS does not permit to estimate vsini values for slowly rotating stars.
line 184: reformulate the sentence - it is not understandable. What are weak magnetic stars?
line 193: MUSICOS is not used for spectropolarimetry since about two decades. It also had 
  much lower spectral resolution.
line 198: reformulate: Mapping technique requires long-term .. to cover the ...
line 207: what do you mean by the field errors? Errors in the age determination of field stars?
  Reformulate this sentence.
line 216: mention that the reliability depends on cluster membership, i.e. on the astrometric data.
  As a matter of fact, a number of Landstreet's "members" are non-members, if Gaia data are used.
line 219: what are different types of dynamo theories?
line 234: a dynamo mechanism that could have worked at some other
  stage of the stellar evolution cannot be excluded.

Sect. 3 line 252: the work with the Balmer magnetometer referes to Angel and Landstreet. Give the proper
  reference.

Sect. 3.1:
line 266: Babcock's catalog is very old - give another, more recent reference, for your statement that
  only a quarter of the chemically peculiar stars possesses magnetic fields.
line 284: mention that the applicability of photometric methods strongly depends on the spectral type of the
  studied stars.
line 310: certainly more than 600 magnetic stars are known. Give a reference.
line 319: all five known Of?p stars
line 319: The first, unfortunately unsuccessful attempt...
line 322: ..with FORS2 and HARPS.... Why is HARPS not mentioned in your descriptions of spectropolarimeters?
line 325: you need to mention that the membership of these stars has to be reconsidered. 13th magnitude
  was already mentioned in the text.
line 349: why is a field of 50kG mentioned? There is no star with a magnetic field stronger than 34kG.

Sect. 3.2:
line 381: what are the different versions of the dynamo theory?
line 386: the reference 28 is very old - the whole paragraph should be rewritten because it is not
  clear what the author wants to say. Why is the paper of Mathys (2017) discussing the
  field strengths in stars with different periods not mentioned?
  Further, Mathys discusses binarity and observational evidence for the merger scenario.
  The whole dynamo discussion is obsolete, but can get an impulse in the framework of the merger scenario.
line 448: the module - the modulus
line 460: explain what you mean by a cyclic process. It is also important to mention the
  broad-band linear polarization measurements by Leroy.
line 471: reformulate "The world system.."
line 476: reformulate "The data obtained unambiguously.."

Sect. 3.3.1 line 529: see my comments on the Balmer magnetometer above.
Sect. 3.3.2 line 569: three times stronger...

Sect. 3.4 line 648: the author is certainly aware of the proper criticism of the work of Kochukhov et al.
  by Stift et al. The existing strong shortcomings have to be mentioned if the author discusses the mapping
  technique.

Sect. 3.5 line 685: what is the ratio between the number of observed stars in the LMC to the number of
  observed galactic stars? Since only OGLE data were used with a sensivity much lower than the current satellite
  data, the conclusion that there is only a small number of spotted stars in the LMC
  cannot be made. Please rephrase.

Sect. 4:
line 720: remove "Thus"
line 728: paragraph starting with this line - present references related to these statements.
line 737: read my comments on dynamo theories and rephrase the text.
line 749: ..FOR youngest objects..???
line 752: explain "decay velocity"

Author Response

Dear referee,

We are deeply grateful for the detailed and useful review of the paper. We understand that you have spent a lot of time analyzing this work and are deeply appreciative of the effort. The author agrees with all your comments and remarks, they are included in the revised version of the paper. I hope these changes will significantly improve the quality of it. 

Below in the file you will find a detailed report on the edits made

Sincerely,
        Iosif Romanyuk

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

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