Astronomer R.G. Chandra: In the Light of His Anglo-American Connection

Eur. Phys. J. HDOI: 10.1140/epjh/e2014-40019-6

Historical document

THE EUROPEANPHYSICAL JOURNAL H

Astronomer R.G. Chandra: In the Light of HisAnglo-American Connection

Saibal Ray1,a, Sudhindra Nath Biswas2,b, and Utpal Mukhopadhyay3,c

1 Department of Physics, Government College of Engineering & Ceramic Technology,Kolkata 700010, West Bengal, India

2 Mahatma Aswini Kumar Dutta Road, Nabapally, Barasat, North 24 Parganas, Kolkata700126, West Bengal, India

3 Satyabharati Vidyapith, Nabapally, Barasat, North 24 Parganas, Kolkata 700126, WestBengal, India

Received 18 May 2013 / Received in final form 26 February 2014Published online 7 April 2014c© EDP Sciences, Springer-Verlag 2014

Abstract. In the present paper we have presented some documents toreveal the longstanding relationship of Indian amateur astronomer R.G.Chandra with the British Astronomical Association and American As-sociation of Variable Star Observers.

1 Introduction

Radha Gobinda Chandra (1878–1975), in spite of being a petty clerk of Treasury Officeof Jessore in undivided India (now in Bangladesh), received international recognitionas an amateur astronomer through his sheer love for astronomy and meticulous ob-servations. A detailed account of his life and works can be found in the study ofBiswas et al. [Biswas et al. 2011]. It will suffice only to mention here that Chandrawas connected with both the British Astronomical Association (BAA) and the Amer-ican Association of Variable Star Observers (AAVSO) in the sense that he regularlycommunicated his observational findings to those organizations and that he did all hisobservations independently with a three inch refracting telescope (the smaller one inFig. 1) which he purchased in 1912 from Bernard and Co. of England and a 6.25 inchtelescope (the larger one in Fig. 1) which was lent to Chandra for his observationsby the Telescope Committee of AAVSO in the year 1926 and Chandra started usingit since 1928. The main motivation of the present work is to highlight the role ofChandra as a responsible member of both BAA and AAVSO as well as reveal somenew findings which were not covered in the aforementioned paper.

a e-mail: [email protected] e-mail: [email protected] e-mail: [email protected]

http://www.epj.org

http://dx.doi.org/10.1140/epjh/e2014-40019-6

2 The European Physical Journal H

Fig. 1. Photograph of aged R.G. Chandra working with his 3 and 6 inches refract-ing telescopes along with a photograph of young Chandra (inset) (Reproduced fromRef. [Biswas et al. 2011]).

2 Initial connections

Chandra’s earliest significant attachment with AAVSO was materialized through thereporting of the observation of Nova Aquilae 1918 (to be discussed afterwards) toEdward Charles Pickering (1846–1919) of the Harvard College Observatory. Pickeringpromptly realized the potential of Chandra as a good observer and accordingly, on14 November 1918, he dispatched an inspiring letter to Chandra accompanied by afew valuable books, Revised Harvard Photometry and some literature on the NovaAquilae 1918. From Eastern India, Chandra was the lone observer of AAVSO to reporthis observational data during the period of the early 20th century. But it should bementioned here that even before Chandra sent his “report” on the “new star” (i.e.Nova Aquilae) to Pickering, he made communication with the AAVSO by expressinghis intention to take part in the process of estimating variables. This point becomesevident from a part of the letter dated 8 July 1918, written by Solon Irving Belly(1854–1931) [Campbell 1932a], on behalf of the AAVSO:

“Situated as you are six hours East of Greenwich, your station should proveof great help in the observation of these variables. . . ”.

On the other hand, the first British connection of Chandra can be traced back throughthe reporting “Search for meteors from Pons-Winnecke Radiant” [Nature 1921], whichgoes as : “R.G. Chandra of Jessore, India, also reports a fruitless search for meteorsin the night of June 25. He states that Prof. Ray of Bolpur saw two meteors radiatingfrom the neighborhood of θ Bootes1. In this way, Chandra came in contact with theBAA and the AAVSO, the two premier organizations of Europe and America inobservational astronomy.

1 Here, Prof. Ray means Jagadananda Roy (1869–1933) of Santiniketan who was arenowned science teacher of the school at Santiniketan under Viswabharati University, Bolpurfounded by the Nobel Laureate poet Rabindranath Tagore (1861–1941).

S. Ray et al.: Chandra’s Anglo-American Connection 3

3 Observation of variable stars

The pioneer amateur variable star observers during the period 1875 to 1910 (i.e. beforethe formation of AAVSO) were Seth Carlo Chandler (1846–1913), Edwin ForrestSawyer (1849–1937), Paul S. Yendell (1844–1918), John H. Eadie (1844–1908) andsome others. Chandler is famous for his three early variable star catalogues, Sawyerpublished in 1882 a catalogue of magnitude of 3415 southern stars, Yendell contributedmore than 125 variable star notes while Eadie contributed a large number of variablestar observations to the Harvard College Observatory.

After its inception in 1911, AAVSO took a leading role in variable star astron-omy. The data of instant brightness collected from the systematic observations ofvariable stars enable astronomers to reveal several physical characteristics, viz. themass, radius, temperature, luminosity, both the internal and external structures andevolution of the stars. In order to achieve a more reliable result, these data are re-quired to be collected in sufficient quantity from various stations all over the globe.In this regard, there were a good number of variable star observers contemporaryto Chandra, from Europe and America on the Western longitudes, but not sufficienton the Eastern side to report their estimations on variable stars to AAVSO. FromIndia Chandra [Campbell 1925] of Jessore, Bengal (230 10′N , 890 10′E), GeorgeE. Jones [Chakrabarty 1999] of Mussoorie, U.P. (300 27′N , 780 06′E) and M.K.Bappu [Campbell 1926] of Begampeth, Hyderabad (170 10′N , 700 20′E) were theonly three to contribute ‘estimates’ to the said Association, since 1919, 1924 andaround 1927, respectively.

Leon Campbell (1881–1951) was elected President of AAVSO in 1919, the yearfrom which Chandra began to report his estimations on variables to that organizationat regular intervals. Thus in the process of serving the “Association” in different rolesfrom the opposite hemispheres of the Earth for years together, Campbell and Chandrawere in close contact until the former died in 1951.

The quality of work done by Chandra can be realized from the remark made ina letter [Campbell 1926], dated 20 June 1922, addressed to him by Harlow Shapley(1885–1972), Director of the Harvard College Observatory:

“May I add a personal word of congratulation for the good work you havebeen doing in the observation of long period variable stars. Your longitude isof considerable importance in this work.”

The available data reported by Chandra to the AAVSO and subsequently publishedin its Monthly Reports, reveal how laborious and ardent he was as an observer ofthe ‘Association’. For instance, during Campbell’s tenure as Recording Secretary ofAAVSO, Chandra’s month-wise reporting of estimates of the brightness of a total of1685 variable stars was the largest among such number in any single year ending Oc-tober 1926, though analysis of the said ‘Report’ of the actual number of estimationsrecorded by observing Julian day-wise shows that Chandra made 1682 estimationson about 160 variables, during the year ending September 1926 [Campbell 1926] (seeTab. 1). Although Chandra himself made the highest number of 247 estimations inthe month of January 1926, yet he was lauded later as one of the three major con-tributors of reports on variables to the AAVSO. As such Campbell as the RecordingSecretary, while publishing those reports sent by 25 observers who made 1358 estima-tions on 313 stars for the month of April 1926, in the Monthly Report of the AAVSO[Campbell 1932a] made the following comments on 12 May 1926:

“Most commendable list have been received the past month from MessrsPeltier, Chandra and Waterfield, their combined records totaling more thanhalf the number of all the observations combined therein.”


Table 1. The highest number of estimates made by Chandra on the variables in any singleyear ending October 1926.

Observed no. No. of actual No. of obs.Months Julian day

of stars estimation reported1925 Oct 2424 424–455 67 118 –

Nov 456–485 109 193 105Dec 486–516 108 169 223

1926 Jan 517–547 115 247 178Feb 548–575 109 220 162Mar 576–606 76 185 226Apr 607–636 87 169 175May 637–667 49 81 –Jun 668–697 53 77 312Jul 698–728 52 74 –

Aug 729–759 59 87 139Sep 760–789 48 62 83Oct 790–820 – – 82

Total 1982 1685

In the month of April 1926, L.C. Peltier, R.G. Chandra and W.F.H. Waterfieldreported 259, 175 and 237 estimations, respectively. Actually, the total of these es-timations are not ‘more than half’ but ‘very nearly equal to half’ of the number13582.

Within a few years he became a competent and indispensable member in observa-tional astronomy. In the course of time, he was contemplating to observe fainter starsof higher magnitude than those were capable to be viewed through his 3-inch refractor.At the same time, he came in contact with J.H. Logan of Dallas, Texas who began toreport his ‘estimates’ probably from October 1926 to the AAVSO as its member andwas in the possession of an 11-inch telescope for his observations [Campbell 1928].In reply to some queries of Chandra which included the size of the telescope re-quired for viewing the stars of higher magnitude, Logan sent a long correspondence[Hoffleit 1942]. From this correspondence, the answer related to information of thesize of telescope, is given below:

“You asked me about the size of telescope necessary to see stars to the 16thor 17th magnitude. There is a formula which can determine this:

Logaperture in inches × 5 + 9.2” (1)

The formula (1) implies that the faintest star can be viewed:(a) through his 3-inch is of Log3× 5 + 9.2 or 11.59 mag, and (b) through the 6 1

4 -inchlent to Chandra by the AAVSO, is of Log6.25 × 5 + 9.2 or 13.18 mag. Due to suchvariations in the capabilities of different sizes of instruments, Chandra could not viewthe faint stars beyond the 12.6 magnitude through his 3-inch refractor. But with thelending of the 6 1

4 -inch refractor from the AAVSO he could detect faint stars up to14.1 magnitude (see Tab. 2).

The AAVSO authorities, in particular Leon Campbell, never missed any opportu-nity to accord appreciation for any worthy work of Chandra for the advancement ofobservational astronomy. On one such occasion, while reporting contributions of mem-bers of the AAVSO for the year ending October 1932, Campbell [Campbell 1932b]

2 Interested readers may consult the ANNEXURE I [Bandyopadhyay 1991] for some ofthe contributions on Variable Stars by Chandra in Annual and Monthly Reports of AAVSO(1920–1921)


Table 2. The magnitude of some of the most faint stars Chandra observed: (A) prior to and(B) post acquisition of 6 1

4-inch telescope.

ObservedStars

Date of observation Report to AAVSO

magnitude Julian day Gregorian day Year Page

A 12.6 185032 RX LYRAE 242 2984 21 Oct 1921 1922 20

12.5 190925 S LYRAE 3613 12 Jul 1923 1923 98

12.4 050492 U ORIONIS 4262 21 Apr 1925 1925 93

12.3 163264 R DRACONIS 3315 17 Sep 1923 1923 07

12.1 180531 T HERCULIS 2960 27 Sep 1921 1922 08

B 14.1 074922 U GEMINORUM 5649 06 Feb 1929 1929 54

14.0 042209 R TAURI 6712 05 Jan 1932 1932 50

14.0 060547 SS AURIGAE 5622 10 Jan 1929 1929 44

13.7 190967 U DRACONIS 5448 20 Jul 1928 1928 81

13.5 004746a RV CASSIOPEIAE 6635 20 Oct 1931 1932 02

highlighted the work of a few, including Chandra, out of 80 observers from variousparts of the globe:

“Of the 33 000 observations, 21 000 were contributed by 10 observers. Ofthese ten, Peltier heads the list with slightly over 4,000 observations, Jones isa close second, and Lacchini comes third. Next in order are Ahnert of Germany,Chandra of India, Baldwin of Australia, and Ensor of South Africa.”

Actually, Chandra reported 1655 estimations, including the highest number of 487estimations in a single month of March, during that period.

Due to World War II, during the period September 1939–September 1945, manyastronomers were on war duty and could not continue their observations. At such cru-cial time Chandra played an important role for the cause of observational astronomy.How nicely he discharged his responsibilities can be revealed from the following ‘NewsNotes’ published by Dorrit Hoffleit [Hoffleit 1942], in the Sky and Telescope under thetitle ‘Variable Star Observations from India’:

“The Recorder of the American Association of Variable Star Observers,Leon Campbell, reports that the observations of variable stars have continuedto flow in from India, despite the difficulties and delay in transportation, anddespite the great menace of the war. He has received large number of estimatesof the brightness of variable stars from R.G. Chandra, of Bagchar, about everysix months. . .”

We would like to hear on this particular issue of the war-affected period from Campbellhimself [Campbell 1946]:

“R.G. Chandra of Bagchar, India, has been an observer since 1920, withmore than 30,000 observations to his credit. Here again, the war greatly inter-fered with his work during the past five years.”

M.W. Mayall made a report in the Popular Astronomy [Mayall 1951] about the con-tribution by Chandra with his ill health even in 1951. We note from Table 3 that hemade 73 observations with 93 estimates.

Some time prior to August 1945, M.K. Bappu was in need of the service of atelescope. As a genuine astronomer Chandra, at the request of Campbell, gladly agreed


Table 3. A photocopy of the list of observations on Variable Stars during April 1951 byChandra (Chandra can be seen as 8th position in the alphabetical order).


to lend his 3-inch telescope to Bappu. For this generous act Bappu conveyed his thanksto Chandra through a letter by saying :

Begampet 14th August, ’45

Dear Mr. Chandra,It is very kind of you to offer me the loan of your 3” Refractor with its accessories

so as to enable me to continue my observations of variable stars and I thank youheartily for the same. I am also grateful to Prof. Campbell for kindly recommendingme to you. . .

Once again thanking you heartily,

I remain

Sincerely Yours,

M.K. Bapuu

Also, Campbell expressed his thanks to Chandra for complying with his requestthrough a letter by saying :

HARVARD COLLEGE OBSERVATORY CAMBRIDGE, MASS

Mr. R.G. Chandra February 2, 1946Bagchar, Jessore P.O., India.

Dear Mr. Chandra,It is certainly generous of you to place on loan to Mr. Bappu the three inch

telescope, and I thank you on behalf of the Association, as well as on my behalf. . .

I am,

Very sincerely yours,

Leon CampbellRecorder, AAVSO.

In the same letter Campbell wished Chandra to be able to make the one-millionthobservation on a variable star. However, in the long run the one-millionth observationwas achieved not by Chandra but Jocelyn R. Gill in April 1946 [Hoffleit 1946].

Since 1919 observational data on variable stars sent by Chandra were regularlypublished in Memoirs of the BAA [Maunder 1929]. In this way he made a goodrelationship with Felix de Roy, Director, Variable Star Section, BAA who in a letter(dated 27 December 1923) expressed his desire to meet Chandra, by writing:“I seize this opportunity in saying that your excellent observations and remarks arealways much valued by this section. . . . I should be personally pleased to meet you ifever you were to cross to Europe.” [Chakrabarty 1999].

Besides Felix de Roy we would like to mention here some other astronomers of theBAA with whom Chandra had a cordial relationship. Here is part of the letter (dated28 August 1928), written by Brown of the BAA to be quoted:

“I acknowledge with thanks the report of 15 complete sheets of your obser-vation of variables made this year ... I have so far only just glanced over yoursheets, but this glance is sufficient to show that you have again done valuable


work, particularly, perhaps, in the regularity of your observations of some ofthe Irregular U Germinorum etc. in spite of the unfavorable weather with whichyou say you have had. . . ”

From another letter (dated 30 January 1941) by Holborn, the then secretary of theBAA, we come to know how indispensable were, for the professionals, the data col-lected by Chandra from the observation of variable stars. Due to his very old age whenChandra tendered his resignation from the membership of the BAA, then Holbornreacted as follows:

“I am passing on your letter of resignation to Mr. Brown who deals withthese things. But I must say, I think it is a great pity to resign at this timewhen the Association is in the utmost need of support.

Your longstanding work for the variable star section too will be greatlymissed just at the time when Lindley and others like myself with full timewar duties have had to give up observing.

I beg to you as an old member to reconsider this decision of yours.”

However, no concrete official document is available to us to ascertain whether Chandraultimately withdrew his resignation or not. We guess he did not, as very sincereChandra thought that without contributing any astronomical data to the BAA heshould not be an ornamental member.

In a month, Chandra made a maximum number of 226 observations with his3-inch telescope in March 1926 and that of 387 observations with 6.25-inch tele-scope in March 1932. Actually, in the year ending in October 1926 he made no fewerthan 1685 observations, of which he made 226 observations in the month of Marchonly [Kochhar 1993]. During his observational period he made as many as 37 215 ob-servations on the variable stars [Kochhar 1993]. Chandra reported 1348 observationson 34 individual variable stars to the BAA [Struve 1962] during the period 1920–1924(Tab. 1) [Struve 1962].

4 Observations of Novae

A nova is a certain type of variable star whose brightness increases abruptly withina short period. As an assiduous observer Chandra had observed a few novae be-sides his detection of the nova Aquilae 1918 or V 603 Aquilae as its first observer.Nova Aquilae 1918 (R.A.: 18h48m43.48s, Dec. +00o29m28.2s) was a bright nova thatoccurred in Aquila constellation in 1918. It reached a peak magnitude of −1.4. Inci-dentally it was the brightest nova of the twentieth century. It is now a well-knownfact that Chandra’s ignorance about the formalities related to the reporting of dis-covery of a celestial object, deprived him of the glory of discovery of the Nova Aquilae1918 [Biswas et al. 2011]. The report sent by Chandra about his observation of NovaAquilae reached Edward Charles Pickering of the Harvard College Observatory sixmonths after its first reporting. When Campbell came to know about Chandra’s ef-fort, he consoled him through some encouraging words in a letter on 16 June 1621:

“You have taken up nova search in a good spirit and I hope you may berewarded some day with a real Nova discovery.”

Along with the usual observation on variables Chandra also estimated the brightnessof 184300 Nova Aquilae in the year 1918. It has been found in the Monthly Reportof the AAVSO for the years 1921, 1922, 1925 and 1926 that during the period of twoyears from September 1921, Chandra made 15 estimations (see Tab. 4) [Eaton 1922]


Table 4. The brightness of the Nova V 603 Aquilae estimated by Chandra during theperiod from September 1921 to September 1923.

Julian day Gregorian day Magnitude242 2940.2 1921, Sep 07 9.0

2984.0 Oct 21 9.33016.0 Nov 22 9.23142.5 1922, Mar 28 9.43178.4 May 03 9.93196.2 May 21 10.03238.2 Jul 02 10.03292.2 Aug 25 10.03312.2 Sep 14 9.93339.1 Oct 11 9.73341.1 Oct 13 9.63563.5 1923, May 23 10.23608.1 Jul 07 10.23643.1 Aug 11 10.33677.2 Sep 14 10.3

and that from September 1924, he made 19 estimations on the brightness of the nova.From these it is found that the brightness of the nova, estimated during the periodof two years from September 1921, were slightly fluctuating in between 9.00 mag and10.3 mag, whereas those for the succeeding years remained almost steady at about10.4 mag which is close to its normal brightness of 10.5 mag. Perhaps Chandra wasable to observe the transition stage of the nova before it declined to its minimumbrightness at steady state.

Another famous nova of the 20th century, Nova Herculis 1934 (R.A.:18h07m30.25s, Dec. +45o51m32.6s) or DQ Herculis [Campbell 1925] was dis-covered by a British amateur astronomer J.P.M. Prentice on 13 December 1934[Struve 1962]. It reached its highest brightness (apparent magnitude 1.5) on 22December 1934 [Wright 1935]. It was a certain type of cataclysmic variable stardesignated as intermediate polars. The nova attained its maximum brightness on22 December 1934. From the text of Campbell’s letter, it is apparent that Chandraobserved the nova DQ Herculis to oscillate in its postnova stage and the samephenomena continued for a long time. The letter, dated 29 March 1935, written byCampbell is as follows:

“I am pleased to acknowledge your postal card of the 16th January, concerningthe first estimates of Nova Herculis. I am glad to note that you have kept watch onthis star and have secured such a continuous series of observations. The fluctuationsnoted in the star certainly been real and these have not ceased even up to present time.”

We also notice about Chandra’s observation from another source [Mayall 1963]report:

“In the early morning hours of December 13, 1934, a nova of magnitude 3.3 wasdiscovered visually by J.P.M. Prentice, an English amateur. It was also discoveredindependently by three members of the A.A.V.S.O.: Leslie Peltier, who was travellingin Arkansas; R.G. Chandra in Bagchar, India; and Margaret Harwood, in Nantucket,Massachusetts”.


In the above letter, dated 29 March 1935, the Recording Secretary of AAVSO LeonCampbell congratulated Mr. Chandra. The letter goes as – “I am pleased to receivesuch a splendid report of observations as made during January and congratulate youon the excellence of observations”. So, this letter of Campbell reveals that Chandraestimated the variability of Nova Herculis for the first time [Biswas et al. 2011].

5 Observation of SV Andromedae

To us it is remarkable that Chandra even observed SV Andromedae by using his 3and 6 1

4 inches refracting telescopes. The record is in the paper written by J. vander Bilt [van der Bilt 1934]. It was published in the very prestigious and authenticBritish journal Monthly Notices of the Royal Astronomical Society with the title “Thelight-variation of V 22 = SV Andromedae”. Incidentally, V 22 = SV Andromedae is aM type variable star of spectral type M 5e – M 7e. In the Introductory part of thepaper it has been mentioned by Bilt that –

“From the list of A.A.V.S.O. observers I have omitted the names of those whohave contributed only a single observation. As to the others I consider it a matterof courtesy not to treat them anonymously, but to give a list of their names andparticulars about their instruments; especially since it appears that the mean deviationof the estimates of these observers (taken as a group) from the final light-curve doesnot differ appreciably from that of my own estimates”.

From this statement about the list of the AAVSO-observers (see Tab. 5) it isclear that Chandra, rather than a single observation, contributed lots of data on SVAndromedae. Also it is obvious from Bilt’s remarks that Chandra’s observational dataand hence the estimates on mean deviation from the final light-curve were comparableto the other World-class observers including the author of the paper himself.

6 Observation of eclipses and transits

Chandra observed the lunar eclipse of 20 February 1924, concentrating on observingstellar occultation during the eclipse which he reported to BAA [Chandra 1924a] asfollows: “Arrangements were made with two friends to observe the Lunar eclipse andoccultation of stars, one to watch the minute hand, the other to watch the secondhand, and both counting the minutes and seconds independently and record the timewhen I shouted ‘one’, ‘two’ and ‘three’ from the telescope. This was carefully done sothat we get a very accurate time. Time was taken from the Jessore Telegraph Officeat 4 p.m. at which hour each day the time is signaled from the Government TelegraphOffice at Calcutta. The sky was very fine and seeing very good: the observations weremade with naked eye, with binoculars and with a 3-inch refractor using powers of 32and 80.” The observational report of the Lunar eclipse of 26 September 1931 waspublished in the JBAA [Chandra 1932] which is very interesting in connection tosome specific observations in detail. Chandra made his observation with the 3-inchrefractor, binocular and naked eye. According to the report, during the eclipse heobserved the lunar craters Aristarchus, Copernicus, Litchenberg, Harding, Kepler,Plato, Tycho and Gassendi as well as the Seas of Fecundity, Serenity, Showers, etc.He also noted the precise timings of appearance and removal of shadow on thosecraters and seas. Chandra reported that the eclipse started at 16h 51.4m GMT andended at 21h 41.4m GMT.


Table 5. A photocopy of the list of AAVSO observers on SV Andromedae (Chandra can beseen as 8th position in the alphabetical order).


Fig. 2. Chandra’s observational diary (1931).

Observation of the Annular Solar Eclipse of 21 August 1933 was also reported byChandra in JBAA [Chandra 1934]. Using his 3-inch refractor, Chandra measured thetimings of the first and second contacts of the eclipse. However, due to presence ofclouds, he could not observe the last contact.

A Transit of Mercury on 7 May 1924, was also observed by Chandra. He reportedthe details of his observation in JBAA [Chandra 1924b] in the following manner: “AtJessore, the sky was free from clouds and the seeing was very good up to 15h GMT. Theobservation of egress was made by projection. After 15h GMT, thin clouds appearedand passed over the Sun, but at the time of egress the space over and around the Sunwas free from passing clouds. The first internal contact occurred at 17h 35m 45s GMTwhile the last external contact was at 17h 38m 45s GMT.”


Fig. 3. Chandra’s observational diary (1932).

Some kind of superstitions regarding eclipse prevail in India. As Chandra hada scientific outlook, he tried to dispel those misconceptions through his writings.For instance, when Calendar Reform Committee (CRC) of Government of Indiawas formed in 1952 under the Chairmanship of famous astrophysicist M.N. Saha(1893–1956), F.R.S. to remove inconsistencies of contemporary Indian calendars(Panchangs), Chandra placed his suggestions to CRC in a letter dated 3 April 1953.In the same spirit, Chandra wanted to enlighten people regarding the scientific expla-nation of ‘Rahu’ and ‘Ketu’ which, to common men, were nothing but demons. So hesent a short communication to the BAA on ‘Rahu’ which was published in the abovementioned journal [Chandra 1935] in a different issue. For ready reference a part ofthe communication is reproduced below:


Fig. 4. Chandra’s observation of Annular Solar Eclipse (1933).

Rahu - There have been several communications to the Association [JBAA 43, 317(1933); JBAA 45, 322 (1935)] regarding ‘Rahu’, but so far there has been no correctexplanation. Hindoo astronomy may be divided into two sections, mythological andmathematical. In the Indian Epics there are many narratives and fables relating tocelestial bodies, and these may be taken to constitute the first of these sections. Aswell as Rahu there is another term Ketu, . . .Rahu being the ascending node and Ketuthe descending node.

In the Sreemat Bhagabat Puran, Part 8, Chapter 9, Shloks 21-23, it is narratedthat Rahu was a Danab (demon), the son of Shinghika, the wife of Biprachitti. TheDanabs were the antiparty of the Devs, having no right to drink the ‘Amrita’, a divineliquor which made the Devs immortal. Rahu made an attempt in disguise to drink theAmrita along with the Devs, but this was pointed out by Surja (the Sun) and Chandra(the Moon). On this, Hari, the Prince of the Devs, cut off the head of Danab Rahu, butas a small quantity of the Amrita entered the throat his head became immortal and wasplaced in the sky as a ‘Graha’. The Sun and Moon having betrayed his attempt to drinkthe Amrita, Rahu developed a hatred for them, which has resulted in his endeavouringto devour them whenever he gets an opportunity; this he cannot do because he hasonly a head and no body.

Thus is the story, from the epic, of Rahu and the cause of eclipses; but Indianastronomers have known the real causes from time immemorial.

As Rahu’s body was not immortal it was thrown away, but at a later date Indianastronomers and astrologers placed the body, as Ketu, 1800 from Rahu in the Zodiac.. . . - R.G. Chandra.

7 Observation of meteors

That Chandra also was a competent meteor observer can be revealed from the re-sponse to one of his reports on such observation sent to the American Meteor Society,Lede Mccormick Observatory, University of Virginia. In reply, from the Headquar-ters of the ‘Society’, dated 5 February 1926, not only his excellent observations wereappreciated but also he was invited to join the said Society, in the following words:


“Your note enclosing to excellent observations of telescope meteors reachedme today. . . . As you are evidently a real worker in astronomy, how would youlike to join the Am. Meteor Society?”

In a letter, dated 23 June 1927, Willard J. Fisher of the Harvard College Observatory(H.C.O.) Cambridge, Massachusetts wanted to know from Chandra about therecorded knowledge of ancient Indians on the Leonid meteors [Chandra 1985]. Froma paper published by Hubert A. Newton [Newton 1865], Fisher found such knowledgefrom the countries like China, Arab and Europe, except India. He was sure aboutthe fact that such wonderful celestial event could not evade the knowledge of ancientIndians. In spite of his best effort, Chandra was sorry for not being able to replythe queries of his request. Yet, Chandra sent him about the incidents of meteor fallsand cometery apparitions available in the Indian epics Mahabharata and Ramayana.In the case of another letter by Chandra dated 7 September 1927, containing somereports on the Indian records of a shooting star shower, Fisher gladly replied on3 October 1927 as follows:

“Dear Mr. Chandra,I have yours about Indian records of shooting star shower, dated Sept. 7, for which

I am greatly obliged. I must confess to a very complete ignorance of the astronomicalliterature to which you refer, and I learn for the first time about the ruling motionsfor the study of astronomy in ancient India.

I am certainly pleased that you are willing to take further trouble with regard tothese matters. Could you not work up the result of your search, negative results aswell as positive, into a paper? Such a paper would be welcome, I am sure, and I haveno doubt that a place for its publication could be found, in India, or failing that herein this country.

Yours very truly,Willard Fisher.”

From available records, it is found that Chandra reported on his successfulobservation of 24 meteors during 1928–1930 and another 9 in 1937. Also, thefollowing report on his observations of 22 meteors was published by Charles P. Oliverin 1931 [Oliver 1931]:

“We have also received, too late for last years’ report, observation of 17 telescopicand 5 casual meteors by R.G. Chandra of Jessore, India.”

8 Observation of comets

Some years after his first British connection, Chandra was successful in observing thecomet 7P/Pons-Winnecke 1927 which he detected on 20 June 1927 at about 15.5h U.T.(21h IST)3 on the line joining the stars γ Draconis and α Lyrae and was nearer to thelatter one (R.A.: 18h48m43.48s, Dec. +00o29m28.2s) [Observer’s Handbook (1999)].He could ascertain the identity of the observed object by consulting the handbook ofBAA.

Following the instruction of A.C.D. Crommelin (1865–1939), the Director of BAA(Comet Section), Chandra also observed the comet 2P/Encke 1927 having periodof 3.30 years [Chandra 1985]. He detected this comet in 1928 at 7 PM from Jessorewith his 3-inch telescope in Pegasus and observed the same until 17 January, 1928.

3 IST or Indian Standard Time = UT + 05h30m.


This comet which appeared to him as a small nebulosity near the Andromeda galaxy(M31) remained visible to observers from 19 October 1927 to 3 April 1928 during thisapparition.

On 24 February 1943, at about 16.5 U.T. (22.00 IST) Chandra noticed a fuzzyobject near the star γ Ursae Majoris [Chandra 1985]. Later, consulting the Handbookof BAA for 1943 he could recognize the object as the long period comet C/1942 X1 Whipple-Fedtke-Tevzadze. Recording the brightness of the comet regularly andconsulting the Journal of BAA, he could confirm that the variability of the cometidentified by him was real and variations in magnitude were due to the influence ofsolar magnetic disturbances during a sunspot maximum.

9 A responsible person

As Chandra became incapacitated to perform any kind of observational activity, onthe advice of AAVSO authorities, he handed over the 6 1

4 -inch refractor to M.K. VainuBappu (1927–1982), in 1958. The said telescope has been installed at the entranceof Vainu Bappu Observatory at Kavalur (780 49.6′E, 120 34.6′N , Altitude - 725 m)in the North Arcot district of Tamil Nadu, India, under the direct supervision of theIndian Institute of Astrophysics. This handing over of the telescope shows Chandra’ssense of responsibility towards astronomy. This dutifulness prompted him not to keepthe equipment in his own custody when he was unable to make proper use of it.

Not only that, when old age forced Chandra to withdraw himself from activeastronomical activities, he donated all his books and periodicals (sent to him by theBAA, AAVSO and other organizations) as well as his legendary 3-inch telescope toBarasat Satyabharati Vidyapith, a Higher Secondary School close to his residence,for the use of future generations. Finally, it may be mentioned that some volumes ofthose Journals are still there in the school library of that institution.

Apart from observation of celestial objects, Chandra was a keen reader ofastronomical journals, including the Sky and Telescope. After reading its March, 1951issue, he became curious about the origin of names of the days in a week. In orderto know about the ‘origin of naming’, he wrote the following letter to the Editor ofthat journal and it was published in its January, 1952 issue:

“Sir,In terminology Talks, March, 1951, under ‘The Week’, I read ‘we readily recognize

the planetary origin of the names. . .But was there any reason, cause, or rule to arrange the names of the days in

alternate order of one outer and one inner planet? For example, after Moon, DiesLunie, the outer Planet Marsis taken for Dies Martis, the inner planet Mercury isfor Dies Mercurii, then the outer planet Jupiter for Dies Jovis. Venus was taken forDies Veneris and next Saturn as Dies Saturni. The Moon is the inner bright orb atnew Moon and the outer on at full Moon, therefore I assume Dies Lunae after Solis.But for the others? I shall be glad if anybody could find out the cause.

R.G. CHANDRA

Sarkarbati,P.O. Sukchar,Dist. 24 Pargana,India (West Bengal).”


In response, Chandra received a brief reply in March 1952, issue from Edgar W.Woolard of Washington D.C. given below:

“The names of the seven planets of the ancient were attached to the 24 hours ofthe day as ruler of these hours, in order of descending distance from the Earth in theancient Greek geocentric system; the planet that rule the first hour was the ruler ofthe day and the day was named after this planet.”

10 Recognition from AAVSO

Apart from tendering appreciation from time to time for his outstanding work inestimations of variables, Chandra was accorded some rare distinction by the AAVSO.In connection to this we would like to quote here from the Centenial History of theAmerican Association of Variable Star Observers [Williams 2011]:

“The case of Radha G. Chandra of Bagchar, Jessore, India, illustrates a growinginternational influence in this period. A clerk in the tax collector’s office by day, heenjoyed watching the stars at night. When Chandra made an independent discoveryof Nova Aquilae 1918 and reported his results to HCO, Campbell recommended himas a member of the AAVSO.”

On one such occasion, in 1932, Campbell intimated him that he was relievedfrom paying annual subscription to the ‘Association’ in the following words[Campbell 1941]:

“In view of the splendid record which you. . . have made during the past years inconnection with variable star observing and in view of the fact a good friend of theAssociation decided to defray the annual dues. . . ”.

Two most prestigious rewards for Chandra were his election as an honourary mem-ber of the BAA on 24 November, 1920 and that of AAVSO on 11 October, 1947. Thenews of his election as honorary member of AAVSO at its Annual Meeting in 1947 atHarvard was reported in the Sky and Telescope [Hoffleit 1947] in the following manner:

“Two outstanding observers were elected to honorary membership: Rev. T.C.Bouton, St Petersburg, Fla, and R.G. Chandra of Bagchar, India.”

In connection to the opportunity for international involvement, the AAVSOCouncil, held in November 1920, gave extraordinary importance and recognition toChandra. The available Record [Williams 2011] on this matter is like this:

“. . . the Council considered a suggestion from Indian member and regularcontributor R.G. Chandra that the AAVSO undertake a statistical analysis of itsobservations database on a regular basis but concluded that the financial resourcesavailable would not permit such an undertaking”.

Another remark can be quoted here as made in a letter, dated 12 December 1950,by Harlow Shapley, Director of the Harvard College Observatory [Chakrabarty 1994]:

“The American Association of Variable Star Observers, with Head-quarters at theHarvard Observatory, is honored to salute you as one of its important contributorsfrom abroad.”


Probably in this same spirit Leon Campbell, Recording Secretary of AAVSO, hadremarked in his article “The Role of the Amateurs in Variable Star Astronomy”: “Inforeign countries we have Radha G. Chandra, official of Bagchar, India. Mr. Chandra,now in his sixtieth year, who has been aiding in the variable star work since 1919,has accumulated probably more observations on variable stars than any other AAVSOforeign observer, well over 50,000” [Chakrabarty 1999].

11 Conclusion

In the context of collaborative scientific work, Chandra made invaluable contributionsin observational astronomy. He did most of his observations from a remote villageBagchar, situated in the far Eastern longitude. Hence the astronomers of Europe andAmerica, being placed in Western longitude, valued his contributions so much. More-over, Chandra had no formal training in astronomical observations. In fact, he was aself-taught amateur astronomer whose accurate observational findings could well beparallel with those of professionals. As Chandra did his duty by sending observationaldata regularly to the BAA and AAVSO, the authority of those organizations helpedChandra by sending books, journals and encouraging letters to enhance his perfec-tion. Those materials boosted Chandra to continue his tireless observations whichwere mostly nocturnal. For these reasons, an inseparable bond of mutual cooperationdeveloped between Chandra and BAA as well as AAVSO which proved to be usefulfor progress of astronomy. No doubt, R.G. Chandra will remain as a beacon of in-spiration to young astronomers of the world for his love, zeal and perseverance forachieving dexterity in astronomical observations.

Acknowledgements. SNB is grateful for personal interactions with the sons and grandson ofR.G. Chandra, and grandson of Kalinath Mukherjee. SR is personally grateful to ProfessorJ.V. Narlikar for his special encouragement to write this article and the authority of IUCAA,Pune for providing Visiting Associateship under which a part of this work was carried out.

References

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Astronomer R.G. Chandra: In the Light of His Anglo-American Connection