A FINDING LIST OF STARS OF SPECTRAL TYPE A7 AND EARLIER IN REGIONS AT HIGH GALACTIC LATITUDES 11. SOUTH GALACTIC POLE* A. G.

Transcription

1 A FNDNG LST OF STARS OF SPECTRAL TYPE A7 AND EARLER N REGONS AT HGH GALACTC LATTUDES 11 SOUTH GALACTC POLE* A G Davis Philip** Nicholas Sandulak*** ABSTRACT An objctiv prism survy of stars of spctral typ A7 and arlir has bn mad of stars in a 230 squar dgr rgio n at th South Galactic Pol as part of an invstigation of galactic structur prpndicular to th galactic plan Th survcy rportd hr was mad with th 4 prism on th Tonantzintla Schmidt tlscop and th UV prism on th Michigan Curtis Schmidt tlscop at Crro '1'01010 A finding list containing positions and spctral typcs for 10 stars is prscntd, with finding charts for th stars too faint to b includd in th CD or BD catalogus lntmduction As part of a stutly of galactic structur prpndicular to th galactic plan, survys ar bing mad of arly typ stars in high galactic latitud s Th first papr in this sris (Philip, 196a) prsntd positions and spctral typs for 34 stars, A5 and arlir, in th HLF 4 rgion (111 = 76, bl = -45 ) Radrs ar rfrrd to this artid for a summary of progrss in th galactic structur programo n this papr w prsnt similar data for 10 stars of typs A7 and arlir in an ara at th South Galactic Pol As notd in th first papr, it is hopd that publication of finding lists will ncourag spctroscopic and photomtric invstigations of ths stars, particularly th faintr ons Som of th brightr stars at th South Galactic Pol hav bn masurd in th UB V systm by vvstrlund (1963) Photomtric obsrvations mad at th North Galactic Pol hav turnd up many intrsting halo objcts Ultimatly, th goal is to diffrntiat th various dasss of arly typ halo objcts am lo dtrmin thir dnsity distribution prpndicular to th galactic plano Obsrvations This papr prsnts a finding list giving positions and spctral typs for 10 stars in a 230 squar dgr rgio n surrounding th South Galact'ic Pol A survy was mad with th 4 objctiv prism on th Schmidt tlscop at Tonantzintla on svral obsrving runs starting in Sptmbr, 1965, and nding in Sptmbr, 1967, by on of us (AGDP) On hour xposurs wr mad on 103aO mulsion which rachd an avrag limiting magnitud of approximatly B = 125 n August, 1967, a scond survy was mad by th othr author with th UV prism (on loa n from th Warnr and Swasy Obsrvatory) on th Michigan Curtis Schmidt tlscop at Crro Tololo Twnty minut xposurs wr mad on BaO mulsion, which bcaus of th lowr disprsion, rachd a limiting ma~nitud of approximatly B = 135 Th disprsion of th spctra on th 4 plats is 20 Amm at Hó; on th UV plats th disprsion is 50 Amm at Hy Both sts of plats wr sarchd indpndntly by ach author and all stars of spctral class A7 or arlir wr dassifid according to th critria st up by Nassau and Van Albada (1947), Nassau and Syfrt (1946) for th 4 spctra, and Nassau and Stphnson (1960) for th UV spctra Th cut off at A7 was chosn bcaus stars of typ FO an" latr can b sgrgatd radily on th basis of th quivalnt strngths of th H and K lins Th rgions covrd by th two sts of plats' d~d not coincid xactly and consquntly for som stars only on spctral typ is listd Th total ara covrd by on or th othr st of plats is approximatly 230 squar dgrs Short xposur plats wr not takn Stars brightr than about Mpg = 7 could not b classifid with assuranc bcaus of ovrxposd imags For th sak of compltnss in th finding list w hav listd all th stars of spctral typ A7 and arlir that fall in our ara from th HD catalogu Th magnituds listd for th stars ar in tndd primarily for idntification purposs Thos for th brightr stars wr takn from th photomtry of Wstrlund (1963) and Wayman (1961) Magnitud stimats for th faintr stars wr mad by masuring imag diamtrs on th Lick Atlas Charts Th photomtry of Bok and Basinski (1964) srvd as calibrations for ths masurmnts Th probabl rror of ths masurs for th faintr stars is + 03 magnituds Contributions from th Crro '1'01010 ntr-amrican Obsrvatory No 37 Dudly Obsrvatory, Stat Univrsity of Nw York at Albany Warnr and Swasy Obsrvatory, Cas "\Vstrn Rsrv Univrsity

2 Th Finding List Th stars ar listd in Tabl and 2 Tabl lists th stars which ar ithr CD or BD stars ami Tabl 2 lists stars too faint to b in ithr catalogu Column lists th catalogu numbr Th stars ar listd in ach tabl in ordr of incrasing right ascnsion (1950) n Tabl 1, columns 2 and 3 list th CD or BD numbr and th HD numbr; columns 4 and 5, th right ascnsion and dclination (Equinox, 1950); columns 6 and 7, th spctral class as dtrmind from th UV and 40 prism plats rspctivly HD spctral classs ar listd for all HD stars in column Column 9 lists th photographic magnitud Tabl 2 has a similar format, xcpt that columns 2 and 3, which list th HD and CD numbrs, and column which lists th HD spctral class, ar missing An astrisk following th numbr indicats a not at th nd of th tabl n th nots, PHL (Haro and Luytn, 1962) and Ch (Chavira, 195) rfr to stars founcl by ths atuhors at th South Galactic Pol which w wr abl to classify on th Schmiclt spctral plats TABLE 1 Stars o{ typ A7 and arlir nar th south galactic pol which ar listd in th BD and CD catalogus No CD HD RA (1950) DEC SP( U V) SP(4 ) SP(HD) mpg o h m AO AO A >A7 A A2 A A * BD-2\ A7 GO \ B A2: A2: AO O \2 A5: A7 A AO: AO: AO AO AO A7 A BD A AO A2: AO A5 71 \ A5 A AO AO A A2 AO: AO A A7 A A7 A7 A A7 A5 A A7 A7 A A7 >A A A A A3 FO A7 A A5 A2: A5 A5 A BD B A5: A5 A A7 A '1 23 AO: BD AO AO A2 A2 AO AO AO A7 A A5 A2 A BD A2 AO BD AO A A A5 A5 A A2 AO

3 T A B L E 1 (cont) No CD HD RA (1950) DEC SP(UV) SP(4 ) SP(HD) mpg h m 44 BD A5 A A2 A2 AO A2 A A7 A7 A A7 A A7 A5 A A7 A AO AO A A5 A3 A5 0 53* A7 A * rJ B9 A B A5 A A5 A A7 A5: A AO AO A2 A * Pco A A7 >A7 A A2 A A2 AO * AO AO AO A5 A2 A A5 A3 A A AO AO A7 A * B * Pco A3 A2 A A2 AO A5: A7 A A2 56 7* AO AO A5: A A2 AO A7 A5 A A5 A3 A A3 A2 A2 6 4 BD A2 A A7 A A5: A3: A A7 A2 6 * _,00 B E >A7 A * AO AO * B5 ES AO AO A7 A A7 A A5 A5 A AO A A2 A A2 AO A7 >A A7 A7 A A7 A A2 A2 AO o,

4 T A B L E 1 (cont) No CD HD RA (1950) DEC SP(UV) SP(4 ) SP(HD) mpll h m A2 A AO A A2 A A7 A AO A A7 A A7 A BD A7 A A A7 A BD A A A AO A A7 114 Nots to Tabl 1 6 1t is vry lnlikly that th disparity in th cassifica- 71 PHL 314 tions is dll to a misidntification 72 Similar to star no 60 abov, L a possibl composit 53 Spctrum obtaind Spt 12, 1966 (4 prism) shows a F + OB dfinit G-band 7 PHL PHL 666 Ton 192 (Ch) 60 Possibl composit of F + OB 90 Ton 194 (Ch) == PHL PHL Ton 195 (Ch) TABLE 2 Stars 01typ A7 and arlirnar th south galacticpol which ar not listd in th BD and CD catalogus No Nam RA (1950) DEC SP(UV) SP(4 ) mpll h m S AO: El AO S A7: N A7: N AO: W AO: El A S A * N >A7 A7: S AO: Wl AO: S AO: El AO AO N AO A El AO: S AO: El AO AO W AO N AO: W AO:

5 T A R L E 2 (con t) No Nam RA (1950) DEC SP( U V) SP(4 ) mpg h D W ' AO: S A2: W AO: N A S AO: W AO: W AO: A El A2: N A5:: 141 :\') W A5: A5: S A3: * S AO: AO: S A * N DA * El AO AO: S AO: El ) A2 A2 U S AO S A3:: N >A7 A El A S A «' El B5 B N A7 >A7 lo \V AO: W AO * S DA N A5: A2: * N A W AO W A5 >A * El AO: AO * N () AO AO * N B W AO 1\ N A7: W A5 A W AO: AO El AO: El AO: )7 El AO N A7: 129 Nols lo Tabl 2 9 A pculiar spctrum was obtaind on August in 43 Ton 13 (Ch) which th hydrogn lins indica t approximatly a E typ but a faint K lin is prsnto On our othr plats th star shows a lat A or arly Ftyp spctrum 47 Ton 191 (CH) = EPM 46934, probabl whit dwarf 32 PHL G-band prsnt 52 PHL Probabl availabl whit dwarf No propr motion data ar 53 PHL !í PHL Ton 201 (Ch) = PHL

6 'CD-33 1l1 2 3 CD-2goS0 CD-22 S6 \ ' -- CD CD CD CD " BD2r " CD;,, Fig la lo Figs la to 19-Finding harts for starstoo,aint to b in th Southrn Durhmustrung or th Cardaba Durh: mustrung Th harts ar 15' of ar on a sid, North is up and East is to th lft Th catalogu star is markd by a dash on ithr sid 01 th star

7 ~~ 1 ~ ' :-0 ' CD-a» l Y' 'CD ' \ \ -- CD ~ CD , BD-2~ ~ lid ' -21't o - CD \ """ -- ' Fig lb CD-2~224 o l

8 CD CD 'CD Figl 21 BD-21<>g1 CD ' r ' CD CD-2go201 CD ' \ ('o n,o ', \: ' " 22

9 ,, CD C D O 3 --, Fig d CD \ CD CD CD CD-2 25 CD CD-24396, ]-

10 ' CD CD CD D CD O Fig l CD-34 33, \ CD CD-24 44, -- t CD '

11 CO , CD >A ' -('0-21' 47 4 '''- 49 ', --, CD CD-23 4S C O CD CD , _-_ Fig f

12 CO CO CD CD \ CO J \ CD Fi~ g

13 A colon aftr th spctral typ indicats that th classification is doubtful, usually bcaus of faintnss but somtims bcaus of ovrlap A >A7 in th spctral classification ntry indicats that th UV or 4 spctrum was class FO or latr f no ntry appars undr th spctral classification, thn ithr th star was too faint to b classifid or it didn't fall in th rgion covrd by th UV or 4 plats Finding charts for th stars too faint to b in th Cordoba Durchmustrung or Bonnr Durchmustrung wil b found in Figur 1 Th charts ar 15' of ar on a sid, North is up and East is to th lft n most cass, a CD or BD star is markd on th chart n th cas that no Durchmustrung star fll in th fild, a squar dgr of th CD or BD chart for that ara, on a rducd sal, is rproducd in on comr of th chart Rmarks Th distribution of th arly typ stars on th sky found in th South Galactic Po! ara is shown in Figur 2 Th apparnt grouping of bright stars (mpg < 90) in th NW quadrant is random Th propr motions of th bright stars ar random and a plot of B- V vrsus V shows no sign of a main squnc which would b th cas if ths stars wr mmbrs of a physical group Th distribution of spctral typ with apparnt magnitud is shown in Figur 3 for spctral classs

14 10000 () w o:: C> w d () O Q () o:: ~() LL O * B- AO (OO)LF3b r-- "(-300) HLF2, \ \ \ \1 10,- () w o:: lb d () o Q () o:: «1- () LL o * ' 10 A2- A7, ~, (OO)LF3b (-30 ) HLF2 r 1\ \ \ \ \ J \ SGP (-90 ) a Fig3b Figs 3a and 3b- Th distribution af lh numbr of stars with apparnt lagnitlld by spctral tyj Fig 3a-slwws th distribution for B9-AO slars, Fig 3b-th distribution for A2-A7 star! Th havy lin marks th distriljlltion lor SGP stars, th light lin, lor NGP stars (Slttbak and Stock, 1949) and dashd Uns lor 1 HLF 2 (Philip, 1966) and LF3b (NaHall and MacRa, 1949) B-AO and A2-A7 Th distribution founu by Slttbak and Stock (1959) at th North Galactic Pol is shown by a lightr soliu lin in ach graph Th uistributions at ach pol ar quit similar Thr appar to b mor stars in ach magnitud intrval for stars faintr than 10th magnitud at th South Galactic Polo For comparison, th distributions founu by Philip (1966) at b = -30 and Nassau and MacRa (1949) b = 0, ar shown by dashd lins Both ths aras ar along }l = 76 Th drop in th curvs for th North anu South Galactic Pols for B > 135 is du to incompltnss in th data For Population 1 stars, a distanc of 500 parscs from th galactic plan is rachd ata B magnituu of approximatly 95 for B-AO stars anu 106 for A2-A7 stars t is xpctd that th majority of th stars in ach of ths groups that ar faintr than 95 and 106 rspctivly will turn out to b mmbrs of Population 11 Studis mad of arly typ NGP stars (Philip, 1967, 196b) with B magnituds > 12 hav shown that th majority of ths stars hav low m indics and high C indics in Stromgrn four-color photomtry Low m and C indics hav bn found to b charactristic of som typs of arly typ, Population 11 stars Similar studis ar in progrss for th SGP stars in this catalogu A comparison of th spctral typs of this survy with Hnry Drapr spctral typs is shown in Figur 4a As was notd by Slttbak anu Stock (1959) and Philip (196a) th Schmidt spctral typs ar slightly latr than th HD typs Figur 4b compars th UV and 4 spctral typs Thr is a vry slight tndncy for th stars to b classifid latr at th lowr disprsion On of us (AGPD) wishs to thank th National Obsrvatory of Mxico for th tim mad availabl for this projct on th Schmidt tlscop This part of th work was supportd by NSF grant GP 6692 Th othr (NS) obtaind th UV spctral plats whil h was a mmbr of th Crro Tololo ntr-amrican Obsrvatory staff His prsnt activitis ar supportd by an ONR grant and this support is gratfully acknowldgd

15 A7 5 x> cfb 3f- (f) (f) <X J t) x> w => <!) o J 2r fij} (X) <X o Q <!) n AoL c#> 9 AO 2 3 H D CLASS Fig4a Figs 4a and 4b-Fig 4a-Campars SGP catalogu class with HD class, Fig 4b-Compars th 4 and UV spctral classs

16 A7 00 CJ) CJ) «J O O v :r At 9 áb 1m 00 áb o AO UV Fig4b CLASS REFERENCES Bok, B J, and Basinski, j, 1964, Mm of th Mt Stromolo Chavira, E, 195, Bol Obs Tonantzintla, No 17, 15 Obs, Vol V, No 16 Haro, G and Luytn, W J, 1962, Bol Obs Tonantzintla, No 22, 37 Nassau, J J and Albada, G B van, 1957, Ap l 106, 20 and MacRa, D J, 1949, Ap l 110,40 and Syfrt, C K, 1946, Ap l 103, 117 and Stphnson, C B, 1960, Ap l 132, 130 Philip, A G D, 1966, Ap l, Supp 12, 391, 1967, Ap l Lttrs, 14, 143, 196a, Bol Obs Tonantzintla, No 29, 215, 196b, Ap l, 152, 1107 Slttbak, A and Stock, J, 1949, Astr Abh Hamburg, No 5 Wayman, P A, 1961, Royal Obs Bull Wstrlund, B, 1963, MNRAS 127,