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French,â JAAVSOâVolumeâ40,â2012120
John Goodricke, Edward Pigott, and Their Study of Variable Stars
Linda M. FrenchIllinoisâ Wesleyanâ University,â Departmentâ ofâ Physics,â P.O.â Boxâ 2900,âBloomington,âILâ61702;â[email protected]
Presentedâatâtheâ100thâSpringâMeetingâofâtheâAAVSO,âMayâ22,â2011;âreceivedâFebruaryâ28,â2012;ârevisedâAprilâ17,â2012;âacceptedâAprilâ17,â2012
Abstractâ Johnâ Goodrickeâ andâ Edwardâ Pigott,â workingâ inâ York,â England,âbetweenâ 1781â andâ 1786,â determinedâ theâ periodsâ ofâ variationâ ofâ eclipsingâbinariesâsuchâasâbâPerseiâ(Algol)âandâbâLyraeâandâspeculatedâthatâtheâeclipsesâofâAlgolâmightâbeâcausedâbyâaââdarkâbody,ââperhapsâevenâaâplanet.ââTheyâalsoâdeterminedâtheâperiodsâofâvariationâofâtheâfirstâtwoâknownâCepheidâvariables,âtheâstarsâwhoseâperiod-luminosityârelationâtodayâenablesâastronomersâtoâdetermineâdistancesâtoâdistantâgalaxies.ââGoodrickeâholdsâspecialâinterestâbecauseâheâwasâcompletelyâdeafâandâbecauseâheâdiedâatâtheâageâofâ21.ââTheâlivesâandâworkâofâtheseâtwoâastronomersâareâdescribed.
1. Introduction
â TheânameâofâJohnâGoodrickeâ(1764â1786;âFigureâ1)âisârecognizedâbyâmanyâastronomersâ today,â butâ fewâ detailsâ ofâ hisâ lifeâ andâ workâ areâ widelyâ known.âSomeâknowâthatâheâobservedâvariableâstars,âsomeâknowâthatâheâwasâprofoundlyâdeaf,âandâsomeâknowâhimâasâanâamateurâastronomer.âGoodrickeâsâcollaborator,âEdwardâ Pigottâ (1753â1825),â isâ evenâ lessâ wellâ known.â Together,â theseâ twoâdeterminedâtheâperiodsâofâvariationâofâeclipsingâbinariesâsuchâasâbâPerâ(Algol)âandâbâLyrae,âspeculatingâthatâtheâeclipsesâofâAlgolâmightâbeâcausedâbyâaââdarkâbody,ââperhapsâevenâaâplanet.âTheyâalsoâdiscoveredâandâdeterminedâtheâperiodsâofâvariationâofâhâAquilaeâandâdâCephei,âtheâfirstâtwoâknownâCepheidâvariables.âTheâ period-luminosityâ relationâ ofâ Cepheids,â ofâ course,â wouldâ laterâ enableâastronomersâ toâ determineâ distancesâ toâ distantâ galaxies.â Inâ 2010,â theâ authorâwasâableâtoâspendâaâsabbaticalâsemesterâatâtheâUniversityâofâYork,âstudyingâtheâjournalsâ andânotebooksâofâGoodrickeâ andâPigottâ inâorderâ toâunderstandâhowâtheseâpioneersâwentâaboutâtheirâwork.â Richardâ Holmesâ (2008)â cautionsâ aboutâ theâ shroudâ ofâ mythsâ thatâ oftenâenvelopsâscientistsâofâgreatâaccomplishment.âOneâsuchâmythâisâthatâofâtheâlone,âheroicâfigure,âstrugglingâagainstâmisconceptionsâperpetratedâbyâ lesserâminds,âagainstâhisâ(orâher)âownâfamily,âandâperhapsâevenâagainstâsocietyâitself.âThisâmythâdoesânotâapplyâtoâJohnâGoodricke.âRather,âheâwasâableâtoâattendâforward-thinkingâschoolsâthatâaddressedâhisâlearningâneedsâandânurturedâhisâtalents,âandâheâhadâtheâsupportâofâaâfamilyâwhoâclearlyâvaluedâandâencouragedâhisâstudies.â
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2. John Goodricke: background and family lifeââ TheâGoodrickeâfamilyâlineâisâlong,âwithâseveralâbranchesâinâEngland.âTheâGoodrickesâofâYorkshireâtookâupâresidenceâatâRibston,âjustâwestâofâtheâcityâofâYork,âinâ1533âwhenâHenryâGoodrickeâbecameâstewardâofâGreatâRibstonâ(Figuresâ2âandâ3).âInâ1641âSirâJohnâGoodrickeâwasâcreatedâtheâfirstâGoodrickeâbaronetâforâhisâserviceâtoâtheâKingâduringâtheâCivilâWars.âJohn,âtheâastronomer,âwasâtheâeldestâgrandsonâofâtheâfifthâbaronet,âalsoânamedâSirâJohnâ(1708â1789).ââ ZdenÄkâ Kopal,â theâ Czech-Britishâ astrophysicist,â onceâ describedâ theâGoodrickesâasââfox-huntingâcountryâsquiresââ(Kopalâ1986),âaâcharacterizationâthatâtheâfactsâdoânotâsupport.âTheâGoodrickeâbaronetsâwere,âforâtheâmostâpart,ânotâcontentâtoâsitâatâhomeâonâtheâRibstonâestate.âSirâHenry,âtheâsecondâbaronet,âwasâtheâEnglishâAmbassadorâtoâSpainâfromâ1678âuntilâ1682,âandâSirâJohn,âtheâastronomerâsâgrandfather,âwasâEnvoyâExtraordinaryâtoâSwedenâfromâ1764âuntilâ1773.âBothâmen,âasâwellâasâtheâastronomerâsâfather,âHenryâ(1741â1784),âservedâasâMembersâofâParliament,âandâbothâbaronetsâwereâmembersâofâtheâKingâsâPrivyâCouncilâ(somewhatâsimilarâtoâtheâU.S.âPresidentâsâCabinet).ââ Johnâ Goodricke,â theâ astronomer,â wasâ bornâ onâ 17â Septemberâ 1764â inâGroningen,â theâ Netherlands,â whereâ hisâ father,â Henry,â wasâ employedâ inâdiplomaticâ service.â Johnâsâ motherâ wasâ bornâ Levinaâ Benjaminaâ Sessler;â herâfatherâwasâPeterâSessler,âaâmerchantâofâNamur,âBelgium.âJohnâwasâtheâeldestâsurvivingâchild,âandâsoâheâwouldâhaveâbeenâtheâheirâ toâ theâbaronetcyâhadâheâlivedâtoâsucceedâhisâfatherâandâgrandfather.â Accordingâtoâtheâfamilyâhistory,âJohnâbecameâdeafâatâtheâageâofâfiveâdueâtoâaâsevereâillnessâthatâhasâbeenâconjecturedâtoâbeâscarletâfever.âAtâtheâageâofâsevenâheâwentâtoâstudyâatâThomasâBraidwoodâsâAcademyâforâtheâDeafâandâDumbâinâEdinburgh,âtheâfirstâschoolâforâdeafâchildrenâinâtheâBritishâIsles.âBraidwoodâwasâveryâsecretiveâinâhisâteachingâmethods.âWeâdoâknowâthatâBraidwoodâadvertisedââtoâundertakeâtoâteachâanyoneâofâaâtolerableâgeniusâinâtheâspaceâofâaboutâthreeâyearsâtoâspeakâandâtoâreadâdistinctlyââ(quotedâinâPritchardâ1963);âthatâhisâpupilsâreadâ lipsâandâsigned;âandâ thatâBraidwoodâhadâoriginallyâbeenâaâmathematicsâteacherâ(BransonâandâMillerâ2002).ââ JohnâwentâonâtoâstudyâatâtheâWarringtonâAcademyâforâthreeâyearsâafterâleavingâBraidwoodâs.âWarringtonâ wasâ oneâ ofâ theâ âFreethinkingââ orâ Non-ConformistâacademiesâoriginallyâfoundedâtoâprepareâclergymenâinâdenominationsâotherâthanâtheâChurchâofâEngland.âItâwasâwellâknownâforâitsâemphasisâuponâmathematicsâandânaturalâphilosophy;âtheâchemistâJosephâPriestleyâhadâtaughtâthereâbutâhadâmovedâ onâ beforeâ Johnâ Goodrickeâ arrivedâ inâ 1778â (Parkerâ 1914).â Johnâ wasâdescribedâ asâ âaâ veryâ tolerableâ classicâ andâ anâ excellentâ mathematicianââ inâ aâschoolâreportâ(Turnerâ1813).âDuringâJohnâsâtimeâatâWarrington,âtheâmathematicsâcurriculumâ (whichâ includedâ astronomyâ inâ theâ secondâ year)â wasâ taughtâ byâWilliamâ Enfieldâ (McLachlanâ 1943).â Enfieldâ wasâ primarilyâ aâ theologian,â butâheâworkedâdiligentlyâatâhisâ teachingâandâeventuallyâpublishedâhisânotesâ asâ aâ
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textbook,âInstitutesâofâNaturalâPhilosophyâ(Enfieldâ1785),âwhichâwentâthroughâmanyâeditionsâonâbothâsidesâofâ theâAtlantic.â Johnâsâmathematicsânotebookâ isâpreservedâinâtheâGoodrickeâcollectionâofâtheâYorkâCityâArchives,âandâtheâfigureâseenâthereâcanâbeâfoundâonâtheâinsideâbackâcoverâ(Goodrickeâ1779;âFigureâ4).
2.1.âTheâWarringtonâsketchââ Theâ drawingâ showsâ severalâ constellations:â Orionâsâ beltâ canâ beâ seen,âalongâwithâtheâbrightestâstarâinâTaurus,ââTheâEyeâofâtheâBull,ââAldebaran;âtheâconstellationâofâAuriga;âandââtheâtwoâbrightestâstarsâinâtheâGemini.ââTheâMilkyâWayâisâshown,âasâwellâasâtheâzodiacâ(orâecliptic),âandâtheâMoon.âAtâtheâbottomâofâtheâpageâisâaâsentenceâdescribingâtheâpositionâofâvariousâstarsâonâeitherâsideâofâtheâmeridian,âaâlineâconnectingâtheânorthâandâsouthâpointsâonâtheâhorizonâandâpassingâthroughâtheâzenith.âTheâstarâpositions,âtogetherâwithâtheâMoonâsâpositionâinâtheâsky,âpermitâdeterminationâofâtheâapproximateâdateâofâtheâdrawing.âTheâonlyâtimeâthatâmatchesâbothâtheâMoonâandâstarâpositionsâisâaâone-weekâperiodâinâlateâNovemberâofâ1779.âOnâ23âNovemberâ1779,âaâtotalâlunarâeclipseâwasâvisibleâoverâ Englandâ (Borkowskiâ 1990).â Johnâ Goodrickeâ wouldâ haveâ hadâ accessâ toâtextbooksâwithâtablesâofâpredictedâeclipsesâ(suchâasâFergusonâ1756);âheâwouldâalsoâhaveâbeenâtaughtâtoâdoâsuchâcalculationsâinâhisâschoolworkâ(Enfieldâ1785).âExactlyâhowâheâcameâ toâproduceâ thisâdrawingâweâmayâneverâknow.âWhatâ isâsignificant,âhowever,âisâthatâheâwasâalreadyâobservingâtheâskyâinâ1779,âatâtheâageâofâfifteen.
2.2.âCorrectingâsomeâpopularâmisconceptionsâaboutâJohnâGoodricke:âaââdeaf-muteâ?â JohnâGoodrickeâisâoftenâdescribedâasââdeafâandâdumb,ââorâaââdeaf-mute.ââEvidenceâfromâtheâGoodrickeâjournalsâsuggestsâthat,âwhileâheâwasâcertainlyâdeaf,âheâalmostâcertainlyâspoke.âHeâevidentlyâwasâableâtoâreadâlipsâ(teachingâstudentsâtoâlip-readâandâtoâspeakâifâtheyâwereâcapableâofâitâwasâpartâofâtheâcurriculumâatâ theâ BraidwoodâAcademy).âTheâ evidenceâ forâ thisâ isâ inâ twoâ passagesâ fromâGoodrickeâsâJournalâofâtheâGoingâofâMyâClockâ(Goodrickeâ1782a):
17âNovemberâ1782:âWhilstâIâwasâwindingâupâtheâClockâtheâsecondâhandâdidânotâgoâonâasâusualâIâspokeâtoâMrâHartleyâ[theâclockmaker]âaboutâitâ&âheâsaidâitâwasâcausedâbyâmyânotâpullingâdownâtheâSpringâhardâenough....
15âDecemberâ1782:âWhilstâIâwasâwindingâupâtheâClockâonâtheâ15thâtheâsecondâhandâdidânotâgoâonâasâusualâAsâthisâisânowâtheâ3rdâtimeâitâdidâso;âIâremonstratedâwithâMrâHartleyâaboutâitâ&âaskedâhimâyeâreasonsâofâitâdoingâsoâHeâgaveâmeâtheâsameâanswerâasâonâtheâ17thâofâNov.âlastâbutâIâdidânotâcreditâhimâHoweverâafterâseveralâtrialsâIâhaveâsinceâhitâuponâtheâtrueâcourseâ&âfoundâthatâitâwasâowingâtoâaâfaultâ
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ofâmyâownâinânotâpullingâtheâspringâdownâhardâenoughâaccordingâtoâHartleyâsâdirectionsâwhichâIâdidânotârightlyâunderstandâorâheâwasânotâveryâparticularâinâexplainingâthemâtoâme.â
â Fromâtheâwordsâalone,ânothingâcouldâbeâclearer:âheâspokeâwithâMr.âHartley,âheâ remonstratedâ withâ Mr.â Hartley.â Theâ secondâ passageâ makesâ itâ evenâ moreâexplicitâthatâtheâconversationâwasâaâverbalâone;âHartleyâexplainedâandâGoodrickeâdidânotâinitiallyâunderstandâtheâexplanations.âHadâtheâdirectionsâbeenâwrittenâout,âitâisâmuchâlessâlikelyâthatâsuchâaâbreakdownâinâcommunicationâwouldâhaveâoccurred.âThus,âtheâavailableâevidenceâsuggestsâthatâGoodrickeâreadâlipsâwellâenoughâtoâcarryâonâbusinessâtransactions,âandâthatâheâmayâwellâhaveâspoken.
2.3.âBurialâPlaceâ ZdenÄkâKopal,â inâhisâ scientificâautobiographyâOfâStarsâandâMenâ (1986),âdescribedâ aâ visitâ toâ theâ churchyardâ ofâ St.â Johnâ theâ Baptistâ atâ Hunsingoreâ(Figureâ5),âtheâburialâplaceâofâJohnâandâtheâotherâGoodrickes,âandâcameâtoâtheâconclusionâ thatâJohnâGoodrickeâhadâbeenâburiedâapartâ fromâhisâ familyâ inâanâunmarkedâ grave.â Kopalâ wrote:â âWhyâ doesâ heâ restâ thereâ forgottenâ byâ allâ hisâclan;âwhyâwasâheânotâburiedâwithâthemâinâtheirâfamilyâvault[?]....ââHeâwentâonâtoâspeculateâthatâJohnâsâparentsâandâgrandparentsâfoundâhisâdeafnessâtoâbeââaâblotâonâtheâfamilyâescutcheon.ââKopalâapparentlyâdidânotâinvestigateâtheâhistoryâofâtheâpresentâchurch;âifâheâhadâheâwouldâhaveâdiscoveredâthatâitâdatesâtoâ1868,âafterâtheâGoodrickeâfamilyâestateâatâRibstonâhadâbeenâpurchasedâbyâtheâDentâfamily.âThereâwasâaâGoodrickeâfamilyâvaultâunderâtheâoldâchurch,âandâthatâvaultâstillâexists.âItâisâmarkedâinâtheâchurchyardâbyâaâstoneâidenticalâtoâthatâusedâforâtheânewâchurch,âwithâonlyâtheâwordsââGoodrickeâVaultââengravedâuponâtheâsideâ(Figureâ6).âTheâburialârecordsâstillâexistâ(N.âYorkshireâCountyâRecordâOfficeââMICâ1685),âandâtheyâshowâthatâJohnâGoodrickeâwasâindeedâburiedâalongsideâhisâparentsâandâgrandparentsâinâtheâfamilyâvault.âAlthoughâtheâdeafâwereâoftenâtreatedâinhumanelyâinâtheâeighteenthâcentury,âJohnâGoodrickeâsâfamilyâgaveâhimâtheâbestâpossibleâeducationâbothâforâhisâscientificâresearchâandâforâhisâstatureâasâtheâHeirâApparentâtoâaâbaronetcy.â Theâ previousâ Goodrickeâ baronetsâ hadâ attendedâ universityâ atâ eitherâCambridgeâ orâ Aberdeen,â andâ Johnâ surelyâ wouldâ haveâ beenâ intellectuallyâqualifiedâforâuniversity.âWhyâheâreturnedâtoâYorkâatâseventeenâtoâliveâwithâhisâfamilyâisâsomewhatâpuzzling.âBothâJohn,âinâhisâjournal,âandâEdwardâPigott,âinâaâdiary,âmakeâoccasionalâreferencesâtoâJohnâsânotâbeingâwell,âsoâperhapsâhisâhealthâhadâalreadyâbegunâtoâfail.âAtâanyârate,âtheâfirstâentryâinâJohnâsâformalâobservingâjournalâ(Goodrickeâ1781)âcomesâearlyâNovemberâ1781,âwhenâheâwrites:ââLastâeveningâatâ9âp.m.âMr.âE.âPigottâdiscoveredâaâcomet.ââ DuringâtheâfirstâfewâentriesâJohnâdescribesâEdwardâsâcorrespondenceâwithâWilliamâHerschelâandâwithâNevilâMaskelyne,âtheâAstronomerâRoyal.âEdwardâsâcontactsâinâtheâastronomicalâworld,âasâwellâasâhisâdiscoveries,âclearlyâimpressedâJohn,âwhoâimmediatelyâsetâaboutâkeepingâaârecordâofâhisâownâobservations.
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3. Edward Pigott: background and family life
â Edwardâ Pigottâsâ father,â Nathanielâ (1725â1804),â wasâ alsoâ anâ astronomer,âandâheâwasâtheâprimaryâsourceâofâEdwardâsâastronomicalâtraining.âTheâPigottsâwereâ relatedâ toâ theâ wealthy,â landedâ Fairfaxâ familyâ ofâYorkshire;â NathanielâsâmotherâAltheaâFairfaxâPigottâwasâtheâsisterâofâCharlesâGregoryâPigottâ(d.â1772),âninthâLordâFairfaxâandâViscountâEmley.âAsâCatholics,âtheâPigottsâfoundâlifeâinâFranceâmoreâcongenialâthanâlifeâinâtheânorthâofâEngland,âandâtheyâspentâaâgreatâdealâofâtimeâthere.âEdwardâwentâtoâschoolâinâbothâcountries,âbutâFrenchâwasâhisâfirstâ language,âwhichâgivesâanâoccasionalââinventedââfeelâtoâtheâwordingâandâspellingâofâhisâjournals.â NathanielâsâprimaryâinterestâwasâinâusingâastronomicalâmethodsâsuchâasâtheâtimingâofâeclipsesâofâtheâMoonâandâtheâJovianâsatellitesâtoâdetermineâlatitudeâandâlongitude.âAlthoughânotâaâwealthyâman,âheâwasâableâtoâacquireâinstrumentsâmadeâbyâtheâfinestâcraftsmenâofâtheâtime,âincludingâRamsden,âDollond,âSisson,âandâ Bird.â Betweenâ 1773â andâ 1775â Nathanielâ andâ Edwardâ collaboratedâ withâcontinentalâ astronomersâ includingâ Messierâ andâ Mechainâ toâ determineâ theâlatitudeâ andâ longitudeâ ofâ severalâ citiesâ inâ theâ Austrianâ Netherlandsâ (nowâBelgium;âPigottâ1778).â NathanielâPigottâownedâpropertyâinâMiddlesexâandâinâWales,âandâinâ1781âtheâfamilyâsettledâinâYork,âwhereâNathanielâhopedâtoâmanageâtheâestatesâofâLadyâAnneâFairfax,â theâsoleâsurvivingâdaughterâofâLordâFairfax,âandâtoâeventuallyâsecureâ theâ estatesâ asâ anâ inheritanceâ forâ Edwardâsâ youngerâ brother,â CharlesâGregoryâPigott.âTheâPigottâ familyâ tookâupâ residenceâ inâYork,â approximatelyâone-quarterâ mileâ fromâ whereâ theâ Goodrickesâ wereâ living.â Hereâ NathanielâconstructedâanâobservatoryâsaidâtoâbeâamongstâtheâfinestâprivateâobservatoriesâinâEngland.ââ AâdiaryâkeptâprimarilyâbyâEdwardâPigottâwithâsomeâentriesâbyâNathanielâ(nowâ inâ theâ Beineckeâ Libraryâ ofâ Yaleâ University)â includesâ storiesâ ofâ jointâGoodricke-Pigottâ familyâ outings.â Thus,â evenâ thoughâ theâ startâ ofâ theâ officialâcollaborationâ datesâ fromâ Johnâsâ beginningâ toâ keepâ theâ observingâ journal,â itâseemsâlikelyâthatâtheâtwoâdiscussedâastronomyâatâanâearlierâdate.
3.1.âInterestâinâvariableâstarsâ Stellarâastronomyâwasâstillâinâitsâinfancyâinâtheâeighteenthâcenturyâ(see,âforâexample:âHoskinâ1982;âWilliamsâandâHoskinâ1983).âAmongâvariableâstars,âaâperiodâhadâbeenâdeterminedâonlyâ forâ theâ longâperiodâvariableâoâCetiâ (Mira).âIsmaelâBoulliau,âbetterâknownâbyâhisâLatinizedânameâBullialdus,âobservedâtheâstarâ systematicallyâ betweenâ 1660â andâ 1666,â obtainingâ anâ accurateâ periodâ ofânearlyâ 333â daysâ (Hoskinâ 1982;â Hatchâ 2011).â Bouilliauâ wentâ onâ toâ considerâsourcesâofâtheâstarâsâvariability,âandâhypothesizedâthatâtheâmostâlikelyâcauseâofâtheâvariationâwasâdarkâregionsâonâtheâstarâcomingâintoâviewâasâitârotated;âinâotherâwords,âspotsâanalogousâtoâsunspots.âThatâlongâperiodâvariablesâdoânotâalwaysâ
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showâanâexactâperiodicityâorâreachâtheâsameâpeakâbrightnessâwasâtoâbeâexpected,âsinceâ theâvariationâ inâ theâSunâsâ lightâdueâ toâsunspotsâ isânotâexact.âBoulliauâsâexplanationâwasâacceptedâandâadoptedâbyâNewtonâinâBookâ3âofâtheâPrincipia,âandâbyâWilliamâHerschelâinâhisâfirstâpublishedâpaperâ(1780),âwhichâcontainedâobservationsâofâMiraâ(Hatchâ2011).â Asâ earlyâ asâ 1778,â whileâ observingâ fromâ Wales,â Edwardâ Pigottâ wasânoticingâthatâbothâtheâreportedâpositionsâandâbrightnessesâofâstarsâvariedâfromâoneâcatalogueâtoâanother,âandâheâspeculatedâonâpossibleâsourcesâofâ theânotedâdiscrepancies.â Heâ continuedâ thisâ practiceâ fromâ York.â Inâ Julyâ ofâ 1781,â forâexample,âEdwardâwroteâinâhisâjournal:
Theâ22ndâstarâofâTychoâsâAndromedaâisâprobablyâtheâoâ(omicron)âofâthatâconstellation,âthoââitâdiffersâveryâconsiderablyâbothâinâLongitudeâandâLatitude,âwhichâIâamâconvincedâisâoccasionedâbyâanâerrorâeitherâinâ theâ Observationâ orâ Calculation,â theâ Princeâ Hesseâ [probablyâWilliamâIV,âLandgraveâofâHesse-Kassel]âobservedâtheâoâthereforeâitâwasâvisibleâinâTychoâsâtimesâandâhasâbeenâsince;âSeeâHeveliusâsâ&âFlamsteedâsâObservations;ânowâitâisânotâprobableâthatâTychoâwouldâhaveâoverlookedâaâstarâofâtheâ3rdâorâ4thâmag.â(Pigottâ1781)
â Aâ discussionâ ofâ theâ positionalâ uncertaintiesâ inâ theâ catalogsâ ofâ Tycho,âHevelius,âFlamsteed,âandâtheâLandgraveâisâbeyondâtheâscopeâofâthisâpaper.âWhatâisâsignificantâinâthisâpassageâisâEdwardâsâtakingânoteâofâdiscrepantâmagnitudeâestimatesâandâcommentingâthatâTychoâwouldânotâhaveâomittedâaâstarâasâbrightâasâtheâthirdâorâfourthâmagnitudeâexactlyâtheâmagnitudeârangeâofâtheâstarsâthatâheâandâJohnâwouldâsoonâstudyâsystematically.âTheâimplicationâisâthatâtheâstarâmightâwellâhaveâvariedâinâbrightness.â Inâtheâautumnâofâ1782âJohnâandâEdwardâdecidedâtoâpursueâobservationsâofââStarsâwhichâareâVariableâorâThoughtâtoâbeâso,ââasâJohnâwroteâinâtheâheadingâofâoneâjournalâentryâinâearlyâNovemberâ(Goodrickeâ1782b).âTheâfirstâstarâonâhisâlistâisâbâPerseiâ(Algol),âwhoseâchangesâinâbrightnessâhadâbeenânotedâasâearlyâasâ1672âbyâtheâItalianâastronomerâGeminianoâMontanari.âInâOctoberâ1782,âEdwardâPigottânoted,ââThisâstarâisâvariableââforâAlgol,âalmostâcertainlyâasâaâresultâofâaâliteratureâsearch,âasâheâhadâmadeânoâextensiveâobservationsâofâtheâstarâupâtoâthatâdate.âOtherâstarsâonâJohnâsâ listâasâcandidatesâforâvariabilityâincludedâdâUrsaeâMajoris,â notâ thoughtâ todayâ toâbeâvariable,â andâaâHerculis,â nowâclassedâasâ aâsemiregularâvariableâwithâamplitudeâofânearlyâoneâmagnitude.â Onâ12âNovemberâ1782,âJohnânoted,â
ThisânightâIâlookedâatâBetaâPerseiâ[Algol],âandâwasâmuchâamazedâtoâ findâ itsâ brightnessâ alteredâItâ nowâ appearsâ toâ beâ ofâ aboutâ 4thâmagnitude.â Iâ observedâ itâ diligentlyâ forâ aboutâ anâ hourâIâ hardlyâbelievedâthatâitâchangedâitsâbrightnessâbecauseâIâneverâheardâofâanyâ
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starâvaryingâsoâquicklyâinâitsâbrightness.âIâthoughtâitâmightâperhapsâbeâowingâtoâanâopticalâillusion,âaâdefectâinâmyâeyes,âorâbadâair,âbutâtheâsequelâwillâshowâthatâitsâchangeâisâtrueâandâthatâIâwasânotâmistaken.â(Goodrickeâ1782c)
â TheâtwoâbeganâcheckingâAlgolâeveryâclearânight.âTheyâdidânotâseeâanotherâdiminutionâ ofâ lightâ untilâ 28â December.â ByâAprilâ theyâ hadâ seenâ consecutiveâepisodesâ ofâ darkening,â andâ wereâ ableâ toâ determineâ thatâ theâ periodâ wasâ veryâshortâcomparedâ toâ thatâofâMira:âonlyâ2âdaysâandâ21âhours.âAccordingâ toâ theâcustomâofâtheâtimeâforâreportingâscientificâresults,âJohnâsentâoffâaâmemorandumâtoâAnthonyâShepherd,âPlumianâProfessorâofâAstronomyâatâCambridge,â toâbeâreadâatâtheâRoyalâSocietyâofâLondon.âAtâtheâsameâtime,âEdwardâPigottânotifiedâNevilâMaskelyne,âtheâAstronomerâRoyal,âandâWilliamâHerschel,âbothâofâwhomâwereâeagerâtoâobserveâAlgol.âTheâvariabilityâwasâquicklyâconfirmedâbyâHerschelâandâ otherâ astronomersâ ofâ theâ Royalâ Society.â Inâ hisâ report,â publishedâ inâ theâPhilosophicalâTransactionsâofâtheâRoyalâSociety,âJohnâstates:
Iâshouldâimagineâ[theâdiminutionâofâlight]âcouldâhardlyâbeâaccountedâforâotherwiseâthanâeitherâbyâtheâinterpositionâofâaâlargeâbodyârevolvingâroundâAlgol,âorâsomeâkindâofâmotionâofâitsâown,âwherebyâpartâofâitsâbody,âcoveredâwithâspotsâorâsuchâlikeâmatter,âisâperiodicallyâturnedâtowardsâtheâearth.â(Goodrickeâ1783)
â Theâ twoâ discussedâ theâ ideaâ ofâ aâ âlargeâ bodyââ revolvingâ aroundâAlgol,âasâ theirâ journalsâbothâ indicate,â andâ inâ theâ journalsâbothâcallâ theâ largeâbodyâaâ planet.â Itâ isâ likely,â asâ Michaelâ Hoskinâ (1982)â suggests,â thatâ theâ planetâhypothesisâoriginatedâwithâEdwardâPigott,âtheâmoreâexperiencedâobserverâandâalwaysâtheâmoreâadventurousâtheorizerâofâtheâtwo.âYetâGoodrickeâwroteâtheâformalâreport,âandâinâAugustâofâ1783âheâwasâawardedâtheâCopleyâMedalâofâtheâRoyalâSociety.â Weâ nowâ believeâ transitsâ ofâ aâ fainterâ stellarâ companionâ toâ beâ theâ correctâexplanationâforâtheâAlgolâsystem.âObservationsâofâtransitsâareâcurrentlyâbeingâusedâbyâNASAâsâKeplerâmissionâtoâdetectâEarthlikeâplanetsâaroundâotherâstars.âYetâinâtheirâownâtimeâGoodrickeâand,âtoâaâlesserâextentâPigott,âwouldâabandonâtheâtransitâhypothesisâinâfavorâofâstarspots.âInâhisâlastâcompletedâpaper,âonâtheâperiodâofâvariationâofâdâCephei,âGoodrickeâwouldâwrite:
What I have before mentioned, that the greatest brightness of ÎŽ Cepheiâdoesânotâseemâtoâbeâalwaysâquiteâtheâsame,âisânotâpeculiarâtoâthisâstar,âbutâisâalsoâtoâbeâobservedâinâtheâotherâvariableâones....EvenâAlgolâdoesânotâseemâtoâbeâalwaysâobscuredâinâtheâsameâdegree,âbeing perceived to be sometimes a little brighter than Ï Persei, and sometimesâlessâthanâit....Thisâmay,âIâsuppose,âbeâaccountedâforâbyâaâ
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rotationâofâtheâstarâonâitsâaxis,âhavingâfixedâspotsâthatâvaryâonlyâinâtheirâsize.â(Goodrickeâ1786)
â SeveralâfactorsâcouldâhaveâcontributedâtoâGoodrickeâsâchangeâofâmind.âByâthisâtime,âheâhadâvisitedâNevilâMaskelyneâatâGreenwichâandâbeenâexposedâtoâtheâopinionsâofâ seniorâ astronomers,âwhoâ favoredâ sunspots,â asâweâhaveâ seen.âButâalso,âtheânatureâofâdâCepheiâsâlightâcurveâdiffersâfromâthatâofâAlgol.âThereâisânotâoneâsingleâisolatedâdiminution,âbutâaâcontinuousâfadingâandâbrightening;âaâpatternâthatâisâlessâeasilyâinterpretedâinâtermsâofâanâeclipse.âFinally,ârâPersei,âconvenientlyâplacedâforâcomparisonâwithâAlgol,âisâitselfâaâvariableâstar,âandâsoâitâmayâwellâhaveâbeenââsometimesâaâlittleâbrighterââandâsometimesâlessâbrightâthanâAlgol.âMostâmodernâobserversâcanâ relateâ toâ theâdilemmaâofâchoosingâaâcomparisonâstarâthatâturnsâoutâtoâbeâvariable!âOnlyâaâcenturyâlaterâwasâtheâeclipseâhypothesisâconfirmedâusingâspectralâanalysisâ(seeâBattenâ1989âforâaâreview).â
4. Other astronomical work
â Johnâ Goodrickeâsâ remainingâ timeâ onâ Earthâ wasâ short.â Heâ continuedâtoâ observeâAlgol;â inâ additionâ toâ determiningâ theâ periodâ ofâdâ Cepheiâ heâ alsoâobtainedâtheâperiodâofâbâLyrae.âInâtheâautumnâofâ1784,âasâGoodrickeâstudiedâdâCephei,âEdwardâPigottâdetectedâtheâvariationâofâanotherâCepheid,âhâAntinoiâ(todayâhâAquilae).âEdwardâwouldâeventuallyâdiscoverâtwoâmoreâvariableâstars,âRâScutiâandâRâCoronaeâBorealis;âheâdiscoveredâtheâspiralâgalaxyâknownâasâM64âbeforeâBode,âandâJeromeâLaâLandeâwouldâwriteâhimâthat
Theâobservationsâwhichâyouâsentâmeâinâ1782âŠhaveâbeenâveryâusefulâinâmyâresearchâintoâaâtheoryâforâMercury,âwhichâIâhaveâpublishedâŠtheirâephemeridesâshowedâmeâforâtheâfirstâtimeâthatâtheâplaceâofâtheâaphelionâwasâtooâfarâadvancedâinâmyâtables.â(LaLandeâ1786)
â Thus,âEdwardâPigottâsâobservationsâmayâwellâhaveâbeenâamongâ theâ firstâshowingâtheâadvanceâofâtheâperihelionâofâMercury!â Johnâ Goodrickeâ diedâ onâ Aprilâ 20,â 1786,â inâ York,â 14â daysâ afterâ beingâelectedâ toâmembershipâ inâ theâRoyalâSocietyâatâ theâageâofâ21.âEdwardâPigottâcompletedâtheirâdeterminationâofâtheâlatitudeâandâlongitudeâofâYorkâandâwroteâofâGoodricke:
Thisâworthyâyoungâmanâexistsânoâmore;âheâisânotâonlyâregrettedâbyâmanyâfriends,âbutâwillâproveâaâlossâtoâastronomy,âasâtheâdiscoveriesâheâ soâ rapidlyâ madeâ sufficientlyâ evince:â alsoâ hisâ quicknessâ inâ theâstudyâofâmathematicsâwasâwellâknownâtoâseveralâpersonsâeminentâinâthatâline.â(Pigottâ1786)
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5. The Goodricke-Pigott legacy
â JohnâGoodrickeâisâbetterâknownâtodayâthanâEdwardâPigott.âTheâUniversityâofâYorkâhasâaâGoodrickeâCollege,âandâtheâdramaticâstoryâofâGoodrickeâsâshortâlifeâfiguresâprominentlyâinâseveralâastronomicalâtextbooksâ(forâexample,âFraknoiâetâal.â2006).âSurelyâGoodrickeâsâbeingâawardedâtheâCopleyâMedalâandâelectedâtoâmembershipâ inâ theâRoyalâSocietyâbroughtâhimârecognition.â Itâ isâclearâ thatâEdwardâPigottâdeservesâatâleastâequalâcreditâforâtheirâjointâwork.âToday,âEdwardâwouldâbeârecognizedâasâaâco-discovererâofâtheâperiodsâofâAlgol,âdâCephei,âandâbâ Lyrae,â whileâ Johnâ wouldâ beâ creditedâ withâ helpingâ discoverâ theâ periodâ ofâhâAquilaeâandâdeterminingâtheâcoordinatesâofâYork.ââ Theâ petitionâ nominatingâ Johnâ Goodrickeâ toâ membershipâ inâ theâ RoyalâSocietyâ wasâ apparentlyâ initiatedâ byâ Nathanielâ Pigott;â co-signersâ includeâNevilâMaskelyne,âAnthonyâShepard,âThomasâHornsby,âSavilianâProfessorâofâAstronomyâatâOxford,âandâWilliamâWales,âaâmemberâofâtheâBoardâofâLongitude,âamongâothers.âEdwardâPigott,âonâtheâotherâhand,âalthoughâdeserving,âwasâneverâevenânominated.âWasâthisâdueâtoâdifferencesâinâtheâsocialâstandingâofâtheâtwo?âWasâthereâaâreluctanceâonâNathanielâsâpartâtoâpushâforâhisâsonâsânomination?âOrâwasâEdwardâsimplyânotâconsideredâaââclubbableâmanâ?âItâisâpossibleâthatâallâofâtheseâplayedâaâpart.ââ Whatâisâcertainâisâthatâtheâtwoâheldâeachâotherâinâhighâregardâandâfrequentlyâexpressedâthatâregardâbothâinâtheirâjournalsâandâinâtheirâpublications.âEdwardâPigottâfelt,âjustly,âthatâhisâfatherâNathanielâdidânotâgiveâhimâenoughâcreditâforâhisâastronomicalâwork,âandâitâisâcertainâthatâNathanielâcutâEdwardâoutâofâhisâwill,âasâevidencedâbyâEdwardâsâpleadingâlettersâtoâhisâgreat-auntâLadyâAnneâFairfaxâ(N.âYorkshireâCountyâRecordâOfficeâZDVâF:âMICâ1132/1201).âEdwardâdidânotâsufferâslightsâlightly.âYetâEdwardâfrequentlyâmentionsâJohnâGoodrickeâsâtalentsâbothâasâanâobserverâandâinâtheâinterpretationâofâdata.âNeitherâinâprintânorâinâEdwardâsâjournalsâisâthereâanyâhintâthatâheâresentedâGoodrickeâsâauthorshipâofâ theâAlgolâpaper,âhisâreceptionâofâ theâCopleyâmedal,âorâhisâelectionâtoâ theâRoyalâSociety.ââ JohnâGoodrickeâclearlyâadmiredâandâlearnedâfromâEdwardâPigott.âEdwardâsâlong-heldâinterestâinâtheânatureâofâtheâstars,âespeciallyâtheirâpossibleâvariability,âfloweredâintoâaâproductiveâscientificâresearchâprogramâalmostâasâsoonâasâheâandâJohnâGoodrickeâbeganâtheirâjointâinvestigations.âTheseâtwoâdeserveâtoâbeâbetterâknown,âandâtoâshareâjointâcreditâforâtheirâdiscoveries.
6. Acknowledgements
â Itâ isâ aâpleasureâ toâ thankâ JoyâCannâandâCarolineâStockdaleâ forâ assistanceâwhileâ workingâ atâ theâ Yorkâ CityâArchives.â Theâ authorâ thanksâAlisonâ Brech,âCharlesâandâAnnieâDent,âMartinâLunn,âAnitaâMcConnell,âJohnâPercy,âandâIanâStuartâforâfruitfulâdiscussions;âRonâEmmonsâforâresearchâassistance;âandâThomasâ
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Williamsâforâaâhelpfulârefereeâsâreport.âResearchâforâthisâworkâwasâcarriedâoutâwhileâtheâauthorâwasâaâVisitingâProfessorâofâPhysicsâinâtheâUniversityâofâYork.âSupportâfromâtheâHerbertâC.âPollockâAwardâofâtheâDudleyâObservatoryâandâfromâaâ Smallâ Researchâ Grantâ ofâ theâAmericanâAstronomicalâ Societyâ isâ gratefullyâacknowledged.ââ Unlessâ otherwiseâ cited,â informationâ onâ Johnâ Goodrickeâ andâ hisâ familyâcomesâ fromâaâ familyâhistoryâoriginallyâwrittenâbyâCharlesâAlfredâGoodrickeâ(1897).â Anâ abbreviatedâ versionâ isâ currentlyâ maintainedâ onlineâ byâ MichaelâGoodrickâ(2010).âTheâprimaryâsourceâofâinformationâonâEdwardâPigottâisâtheâ1999âarticleâbyâAnitaâMcConnellâandâAlisonâBrechâ(1999)âentitledââNathanielâandâEdwardâPigott,âItinerantâAstronomers.â
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French,â JAAVSOâVolumeâ40,â2012 131
Figureâ2.âRibstonâHallâinâtheâseventeenthâcentury.âFromâtheâGoodrickeâfamilyâhistoryâwebsiteâmaintainedâbyâMichaelâGoodrickeâatâhttp://www.goodrick.info/main.htm
Figureâ 3.â Ribstonâ Hallâ today.â ©â Copyrightâ Gordonâ Hattonâ <http://www.geograph.org.uk/profile/4820>â andâ licensedâ forâ reuseâ underâ thisâ CreativeâCommonsâLicense<http://creativecommons.org/licenses/by-sa/2.0/
Figureâ1.âJohnâGoodrickeâ(1764â1786).âPastelâportraitâbyâJamesâScouler,ânowâtheâpropertyâofâtheâRoyalâAstronomicalâSociety.âUsedâwithâpermissionâofâtheâRAS.
French,â JAAVSOâVolumeâ40,â2012132
Figureâ6.âTheâeast-facingâsideâofâtheâmarkerâstoneâforâtheâvault.âTheâonlyâengravingsâareâtheâletterââEââatâtheâtopâandâtheâwords,ââTheâGoodrickeâVault.â
Figureâ4.âDrawingâfoundâinâtheâinsideâbackâcoverâofâJohnâGoodrickeâsâmathematicsânotebookâfromâWarringtonâAcademy,â1779â1780.âTheâconstellationsâofâOrion,âTaurus,âAuriga,âandâGeminiâareâshown,âalongâwithâtheâMoon,âMilkyâWay,âandâZodiac.âPositionsâofâstarsâareâgivenâthatâareâconsistentâwithâtheâdrawingâhavingâbeenâmadeâinâNovemberâ1779.âReproducedâfromâanâoriginalâheldâbyâCityâofâYorkâCouncilâArchivesâandâLocalâHistoryâ(Goodrickeâ1779).
Figureâ5.âTheâchurchâofâSt.âJohnâtheâBaptistâinâHunsingore.âTheâlow,âflatâstoneâjustâtoâtheâleftâofâcenterâinâtheâphotographâmarksâtheâlocationâofâtheâGoodrickeâvault.