Gamma Cassiopeiae: History and Mystery

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please note the following minor corrections/typos:

page 4, 

line 73: please indicate the epoch of those observations
line 77: what does "other observational epoch" mean? Which period does it refer
to?

page 7,

line 137: axis and vsini remain constant. --> axis and projected rotational
velocity vsini remain constant.

line 145: companion During --> companion. During

Author Response

Comments to the referee 1 notes:

 

Comment 1) page 4, line 73: please indicate the epoch of those observations

Responce 2: The epoch of the observations was indicated

Comment 2) page 4, line 77: what does "other observational epoch" mean? Which period does it refer to?

Responce 2:

The period of observation was indicated.

Comment 3) page 7, line 137: axis and vsini remain constant. --> axis and projected rotational velocity vsini remain constant.

Responce 3: The correction is made.

Comment 4) page 7, line 145: companion During --> companion. During

Responce 4: Corrected

Reviewer 2 Report

Comments and Suggestions for Authors

The paper deals with a very interesting object, gamma Cas, a prototype of a subclass of Be variable stars with strong brightness variations, complicated spectroscopic phenomena, and X-ray emission. The authors correctly emphasize that the prototype remains enigmatic after decades of research. In general, the paper is a thorough review of articles concerning the star. It definitely deserves publication.

I have a number of remarks and suggestions towards improvement of the paper.

The abstract is insufficiently informative, it does not give a reader a correct impression of what to expect from the paper.

In lines 7-9, the authors write: "Many hundreds and even thousands of years people of the Nothern hemisphere have been observing the variability of the middle star in the beautiful constellation of Cassiopeiae". Actually, people did not know anything about the existance of variable stars (with the exception of Novae) till the discovery of Mira Ceti at the end of the 16th century; why thousands of years? Also, "gamma Cassiopeiae" but "constellation of Cassiopeia".

Throughout the paper, the spelling of the word "disk" differs from one case to another (see, for example, lines 11, 130, 139-140).

In the caption to Fig. 2, I recommend to give a reference to the source of this figure and to add "J.B.L." in front of "Foucault".

The authors call A. Secchi the "discoverer of canals on Mars surface". Indeed, Secchi noticed linear structures on Mars, but the term "canals" (Italian "canali") was introduced by G. Schiaparelli, as if he meant artificial structures, as is implied with the English word "canals".

I do not like the name "Cat Rock" used by the authors (line 71). It is "Koshka" (Cat) mountain, large enough for the observatory, and the observatory still exists (though the authors write: "was situated").

In line 75 and in references 17, 22 the spelling of the name "Boyarchuk" is different. At that time, translators of the Russian Astronomical Journal used the spelling "Boyarchuk".

In line 126, we read: "fall to nearly 3.0". If the authors mean the light curve in Fig, 4, the magnitude at minimum light is about 2.4; if they mean anything else, a reference would be helpful. The GCVS currently also gives 3.0 V for the magnitude at minimum. In the caption to Fig. 4, I recommend to indicate the system of magnitudes (probably visual).

In lines 139-140, the word "as" is repeated three times - two of them in the very beginning of the sentence (typo?). In line 145, there is no full stop before the word "During".

Comments on the Quality of English Language

The language problems start with the abstract ("untranslated into English papers of Soviet period"). I have a feeling that problems with understanding are possible (not for me, also a Russian native speaker),

Author Response

Comments to the referee 2 notes:

Comments 1) The abstract is insufficiently informative, it does not give a reader a correct impression of what to expect from the paper.

Response 1: Abstract is corrected

Comments 2) In lines 7-9, the authors write: "Many hundreds and even thousands of years people of the Nothern hemisphere have been observing the variability of the middle star in the beautiful constellation of Cassiopeiae". Actually, people did not know anything about the existence of variable stars (with the exception of Novae) till the discovery of Mira Ceti at the end of the 16th century; why thousands of years? Also, "gamma Cassiopeiae" but "constellation of Cassiopeia".

Response 2:

The text is corrected.

Comments 3) Throughout the paper, the spelling of the word "disk" differs from one case to another (see, for example, lines 11, 130, 139-140).

Response 3:

Throughout the paper, the version "disc" is accepted

Comments 4) In the caption to Fig. 2, I recommend to give a reference to the source of this figure and to add "J.B.L." in front of "Foucault".

Response 4: The source of the figure is given, J.B.L. is added

Comments 5) The authors call A. Secchi the "discoverer of canals on Mars surface". Indeed, Secchi noticed linear structures on Mars, but the term "canals" (Italian "canali") was introduced by G. Schiaparelli, as if he meant artificial structures, as is implied with the English word "canals".

Response 5: We correct the text and mention G. Schiaparelli too. We base on the text of the paper by G.Abetti (https://articles.adsabs.harvard.edu/pdf/1960ASPL....8..135A): «in 1859 Secchi observed Mars intensively and discovered two permanent dark "canali" between the two large equatorial continents. To him we owe the name 'canali', later adopted by Schiaparelli.»

Comments 6) I do not like the name "Cat Rock" used by the authors (line 71). It is "Koshka" (Cat) mountain, large enough for the observatory, and the observatory still exists (though the authors write: "was situated").

Response 6: The name "Cat Rock" is changed to "Koshka" (Cat)”.

Comments 7) in line 75 and in references 17, 22 the spelling of the name "Boyarchuk" is different. At that time, translators of the Russian Astronomical Journal used the spelling "Boyarchuk".

Response 7:

The spelling "Boyarchuk" is used throughout all the paper.

Comments 8) In line 126, we read: "fall to nearly 3.0". If the authors mean the light curve in Fig, 4, the magnitude at minimum light is about 2.4; if they mean anything else, a reference would be helpful. The GCVS currently also gives 3.0 V for the magnitude at minimum. In the caption to Fig. 4, I recommend to indicate the system of magnitudes (probably visual).

Response 8:

Indeed, the minimum photoelectric magnitude in Fig. 4 (light curve in 1936-1937) is only 2.44. The minimum of the visual magnitude, close to 3.0, was reached only in 1940. The caption to Fig. 4 is corrected. We also add the references to Fig. 8 and Fig. 1 in paper by Doazan et al. (1983), to convince the reader that the magnitude of the star falls up to 3.0.

Comments 9) In lines 139-140, the word "as" is repeated three times - two of them in the very beginning of the sentence (typo?). In line 145, there is no full stop before the word "During".

Response 9: Corrected