Spectroscopic Surface Gravity Estimates for Subgiant MK Spectral Standard Stars Eric Mamajek 8/26/2013 I was unable to find a compilation of typical log(g) surface gravity values for stars spectrally classified as subgiants (luminosity class IV). Here I construct one based on published spectroscopic log(g) values for subgiant standard stars. Subgiant standards were taken by compendium of spectral standard stars http://www.pas.rochester.edu/~emamajek/spt/ The subgiant standards are listed in the *IV.txt files, and a preliminary assessment of the quality of the standards was made (those that showed the most consistency in the literature, and/or had the best pedigrees were used). Spectroscopic log(g) values were taken from the most recent version of the PASTEL catalog of stellar spectroscopic parameters (Soubiran et al. 2011; version 2013-04-01; http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/pastel; accessed 8/26/2013). As much as I dislike polynomial fits which use spectral type as a variable, I decided to do it in this case as surface gravity was fairly insensitive to spectral type. I quantified spectral type as follows: SpT=0 => B0IV, SpT=10 => A0IV, SpT=20 => F0IV, SpT=30 => G0IV, SpT=40 => K0IV. All stars had spectral types between B0V and K1V [0 through 41]. The lowest order polynomial fit which did a reasonable job fitting the SpT vs. log(g) data was: log(g) = 4.2197037039017085e+000 - 1.8596748210408906e-001*spt + 2.4340886159923317e-002*spt^2 - 1.3285889634321057e-003*spt^3 + 3.3193957646843436e-005*spt^4 - 3.1501729718472546e-007*spt^5 Unfortunately the rms scatter in the fit is +-0.19 dex, reflecting a mix of differences amongst spectroscopic log(g) values published for a single subgiant standard star, and standard-to-standard differences. Given the heterogeneity of the data, I do not attempt to disentangle which effects dominate, but the data seem to suggest that +-0.2 dex (or so) rms accuracy in log(g) is a reasonable lower limit on the predictive power of luminosity class "IV" to predict surface gravity. Here is a preliminary spectral type vs. spectroscopic log(g) sequence for subgiants: SpT log(g) B0IV 4.22+-0.2 B5IV 3.75+-0.2 B9IV 3.75+-0.2 A0IV 3.77+-0.2 A5IV 3.86+-0.2 F0IV 3.91+-0.2 F5IV 3.91+-0.2 G0IV 3.91+-0.2 G2IV 3.89+-0.2 G5IV 3.83+-0.2 K0IV 3.42+-0.2 K1IV 3.25+-0.2 # PASTEL spectroscopic parameters for subgiant standard stars # Taken from http://cdsarc.u-strasbg.fr/viz-bin/Cat?B/pastel #SpT Name Teff uTeff Logg uLogg [Fe/H] u[Fe/H] Author bibcode 0.2 phi01_Ori 28340 1900 Zorec 2009A&A...501..297Z 0.2 phi01_Ori 30000 300 4.050 0.050 0.020 0.040 Nieva 2012A&A...539A.143N 0.5 lam_Lep 29890 4.220 -0.240 Gies 1992ApJ...387..673G 0.5 lam_Lep 30400 300 4.300 0.050 0.040 0.070 Nieva 2012A&A...539A.143N 0.5 lam_Lep 31500 4.050 1.000 Hardorp 1970ApJS...19..193H 1.0 zet_Tau 21135 Moujtahid 1999A&A...349..151M 1.0 zet_Tau 21478 4.220 Chauville 2001A&A...378..861C 2.0 gam_Peg 20160 0.480 Snidgers 1969A&A.....1..452S 2 gam_Peg 21870 1390 Zorec 2009A&A...501..297Z 2 gam_Peg 21913 3.700 0.040 Peters 1976ApJS...30..551P 2 gam_Peg 22000 400 3.950 0.050 0.010 0.070 Nieva 2012A&A...539A.143N 2 gam_Peg 22670 4.020 -0.340 Gies 1992ApJ...387..673G 2 del_Cet 21250 400 3.800 0.050 0.060 0.100 Nieva 2012A&A...539A.143N 2 del_Cet 21500 500 4.100 0.100 Levenhagen 2006MNRAS.371..252L 2 del_Cet 23160 1500 Zorec 2009A&A...501..297Z 2 del_Cet 23750 4.080 -0.240 Gies 1992ApJ...387..673G 2 zet_Cas 20160 0.480 Snidgers 1969A&A.....1..452S 2 zet_Cas 20750 200 3.800 0.050 0.050 0.070 Nieva 2012A&A...539A.143N 2 zet_Cas 21850 1390 Zorec 2009A&A...501..297Z 2 zet_Cas 22180 3.920 -0.230 Gies 1992ApJ...387..673G 3 iot_Her 17500 200 3.800 0.050 0.010 0.080 Nieva 2012A&A...539A.143N 3 iot_Her 18000 4.000 -0.400 Peters 1970ApJ...159..525P 3 iot_Her 19100 1170 Zorec 2009A&A...501..297Z 3 iot_Her 19385 3.500 0.710 Aller 1967cmrs..R....339A 3 iot_Her 20160 3.750 0.000 Kodaira 1970A&A.....6...93K 5 tau_Her 14824 3.650 -0.130 Adelman 1986A&AS...64..173A 5 tau_Her 14824 3.650 -0.570 Adelman 1988MNRAS.230..671A 5 tau_Her 14824 4.000 0.560 Adelman 1977MNRAS.181..667A 5 tau_Her 15000 3.950 0.150 Smith 1993A&A...274..335S 5 tau_Her 16350 940 Zorec 2009A&A...501..297Z 6 19_Tau 14180 740 Zorec 2009A&A...501..297Z 7 16_Tau 14020 720 Zorec 2009A&A...501..297Z 8 alf_Del 11220 450 Zorec 2009A&A...501..297Z 9 134_Tau 0.000 Adelman 1985A&A...152..434A 9 134_Tau 10850 4.100 -0.050 Smith 1993A&A...274..335S 9 134_Tau 10957 3.900 0.080 Adelman 1984MNRAS.206..637A 10 gam_Gem 0.080 Hill 1995A&A...294..536H 10 gam_Gem -0.050 Strom 1966AJ.....71..181S 10 gam_Gem 9040 280 Zorec 2009A&A...501..297Z 10 gam_Gem 9260 3.600 -0.110 Adelman 1992PASP..104..316A 10 gam_Gem 9260 3.600 -0.120 Adelman 1994PASP..106.1239A 10 gam_Gem 9341 di Benedetto 1998A&A...339..858D 10 gam_Gem 9440 3.590 -0.080 Hill 1993A&A...276..142H 11 rho_Peg 9528 67 Blackwell 1998A&AS..129..505B 11 rho_Peg 9749 di Benedetto 1998A&A...339..858D 12 bet_Ser 8542 77 Blackwell 1998A&AS..129..505B 12 bet_Ser 8810 270 Zorec 2009A&A...501..297Z 13 HR_4293 8217 74 Blackwell 1998A&AS..129..505B 13 HR_4293 8305 di Benedetto 1998A&A...339..858D 15 tau_Peg 7655 3.780 -0.280 Erspamer 2003A&A...398.1121E 20 eps_Cep 7244 4.020 0.080 Erspamer 2003A&A...398.1121E 22 32_Tau 6852 80 Casagrande 2011A&A...530A.138C 25 48_Gem 6860 108 Casagrande 2011A&A...530A.138C 26 alf_Tri 6288 3.910 0.000 Balachandran 1990ApJ...354..310B 26 alf_Tri 6321 57 Blackwell 1998A&AS..129..505B 26 alf_Tri 6400 80 Casagrande 2011A&A...530A.138C 27 sig_Peg 6072 3.970 -0.490 Francois 1986A&A...165..183F 27 sig_Peg 6072 3.970 -0.530 Francois 1986A&A...160..264F 27 sig_Peg 6072 3.970 -0.620 Hearnshaw 1974A&A....34..263H 27 sig_Peg 6142 4.050 -0.410 Balachandran 1990ApJ...354..310B 27 sig_Peg 6186 3.970 -0.300 0.050 Ramirez 2007A&A...465..271R 27 sig_Peg 6200 4.000 -0.300 Cunha 2000ApJ...530..939C 27 sig_Peg 6212 80 3.850 0.100 -0.260 0.070 Fuhrmann 2000Priv.C........F 27 sig_Peg 6222 3.670 -0.330 Gratton 1989A&A...208..171G 27 sig_Peg 6229 30 3.870 0.060 -0.190 0.020 Takeda 2005PASJ...57...27T 27 sig_Peg 6232 3.900 -0.260 Zhang 2006A&A...449..127Z 27 sig_Peg 6240 100 3.770 0.100 -0.160 0.070 Reddy 2003MNRAS.340..304R 27 sig_Peg 6250 4.140 -0.230 Gratton 1996A&A...314..191G 27 sig_Peg 6250 50 4.000 0.250 -0.200 0.090 Randich 1999A&A...348..487R 27 sig_Peg 6276 4.020 -0.040 Qui 2002PASJ...54..103Q 27 sig_Peg 6288 3.970 -0.250 Edvardsson 1993A&A...275..101E 27 sig_Peg 6288 70 3.970 0.300 -0.250 0.070 Castro 1999MNRAS.305..693C 27 sig_Peg 6363 80 Casagrande 2011A&A...530A.138C 27 sig_Peg 6400 4.000 -0.120 Mishenina 2003ARep...47..422M 28 ups_Peg 5928 109 Alonso 1999A&AS..139..335A 28 ups_Peg 5942 42 Blackwell 1998A&AS..129..505B 28 ups_Peg 5943 72 Ramirez 2005ApJ...626..446R 28 ups_Peg 5954 99 Alonso 1996A&AS..117..227A 28 ups_Peg 5963 di Benedetto 1998A&A...339..858D 28 ups_Peg 6190 80 Casagrande 2011A&A...530A.138C 28 ups_Peg 6226 520 Gonzalez Hernandez 2009A&A...497..497G 30 eta_Boo 5091 0.440 Herbig 1966AnAp...29..593H 30 eta_Boo 5942 115 3.750 0.110 0.180 0.030 Allende Prieto 2004A&A...420..183A 30 eta_Boo 5943 3.380 0.200 Gratton 1996A&A...314..191G 30 eta_Boo 6000 3.660 0.250 Feltzing 2001A&A...367..253F 30 eta_Boo 6000 3.830 0.160 McWilliam 1990ApJS...74.1075M 30 eta_Boo 6023 70 3.760 0.100 0.280 0.070 Fuhrmann 2000Priv.C........F 30 eta_Boo 6030 80 3.900 0.050 0.240 0.070 Bruntt 2010MNRAS.405.1907B 30 eta_Boo 6035 3.940 0.280 Luck 2006AJ....131.3069L 30 eta_Boo 6035 3.940 0.280 0.100 Luck 2005AJ....129.1063L 30 eta_Boo 6038 75 Ramirez 2005ApJ...626..446R 30 eta_Boo 6068 3.830 0.190 Edvardsson 1993A&A...275..101E 30 eta_Boo 6085 54 3.700 0.100 0.280 0.040 Gonzalez 2010MNRAS.403.1368G 30 eta_Boo 6141 80 Casagrande 2011A&A...530A.138C 30 eta_Boo 6194 110 4.080 0.320 0.170 0.090 da Silva 2011A&A...526A..71D 30 eta_Boo 6219 4.010 0.300 Balachandran 1990ApJ...354..310B 30 eta_Boo 6222 3.800 0.160 Kuroczkin 1977AcA....27..145K 30 eta_Boo 6300 4.180 0.290 0.040 Takeda 2005PASJ...57...27T 30 eta_Boo 6301 406 Gonzalez Hernandez 2009A&A...497..497G 32 phi_Vir 5521 50 3.300 0.250 -0.060 0.090 Randich 1999A&A...348..487R 32 phi_Vir 5600 3.900 -0.020 Mallik 1998A&A...338..623M 35 mu_Her 4667 0.100 Herbig 1966AnAp...29..593H 35 mu_Her 4941 0.480 Herbig 1966AnAp...29..593H 35 mu_Her 5397 107 3.960 0.090 0.260 0.070 Allende Prieto 2004A&A...420..183A 35 mu_Her 5419 4.100 0.300 Vilhu 1978NInfo..45...90V 35 mu_Her 5419 4.100 0.320 Kyrolainen 1986A&AS...65...11K 35 mu_Her 5450 3.700 0.110 Mallik 1998A&A...338..623M 35 mu_Her 5496 33 Blackwell 1998A&AS..129..505B 35 mu_Her 5509 4.000 0.210 0.060 Ramirez 2007A&A...465..271R 35 mu_Her 5520 3.700 0.040 McWilliam 1990ApJS...74.1075M 35 mu_Her 5538 3.910 0.160 Hearnshaw 1974A&A....34..263H 35 mu_Her 5540 3.950 0.240 Luck 2006AJ....131.3069L 35 mu_Her 5540 3.950 0.240 0.060 Luck 2005AJ....129.1063L 35 mu_Her 5580 10 3.990 0.030 0.290 0.020 Takeda 2005PASJ...57...27T 35 mu_Her 5583 78 3.990 0.180 0.280 0.050 da Silva 2011A&A...526A..71D 35 mu_Her 5592 70 3.940 0.100 0.240 0.070 Fuhrmann 2000Priv.C........F 35 mu_Her 5596 80 3.930 0.100 0.230 0.070 Fuhrmann 1998A&A...338..161F 35 mu_Her 5597 44 4.100 0.060 0.300 0.030 Valenti 2005ApJS..159..141V 35 mu_Her 5650 4.000 0.250 Mishenina 2003ARep...47..422M 35 ome_Sgr 5419 3.720 -0.130 Francois 1986A&A...160..264F 35 ome_Sgr 5514 30 3.710 0.130 0.000 0.050 da Silva 2012A&A...542A..84D 35 ome_Sgr 5533 80 Casagrande 2011A&A...530A.138C 35 ome_Sgr 5546 100 3.920 0.100 0.070 0.060 Luck 2006AJ....131.3069L 35 ome_Sgr 5550 50 3.950 0.050 0.050 0.050 Heiter 2003AJ....126.2015H 38 bet_Aql 4383 0.080 Herbig 1966AnAp...29..593H 38 bet_Aql 4990 30 Blackwell 1998A&AS..129..505B 38 bet_Aql 5030 80 3.550 0.080 -0.210 0.070 Bruntt 2010MNRAS.405.1907B 38 bet_Aql 5047 3.510 -0.210 0.040 Ramirez 2007A&A...465..271R 38 bet_Aql 5091 3.150 0.290 Gratton 1982MNRAS.201..807G 38 bet_Aql 5097 50 3.500 0.250 -0.270 0.090 Randich 1999A&A...348..487R 38 bet_Aql 5100 3.600 -0.300 McWilliam 1990ApJS...74.1075M 38 bet_Aql 5106 183 3.540 0.120 -0.150 0.090 Allende Prieto 2004A&A...420..183A 38 bet_Aql 5110 3.600 -0.170 Fuhrmann 2004AN....325....3F 38 bet_Aql 5143 -0.230 Bajcar 1969CoSka...4...63B 38 bet_Aql 5160 3.680 -0.120 Luck 2006AJ....131.3069L 38 bet_Aql 5160 3.680 -0.120 0.050 Luck 2005AJ....129.1063L 38 bet_Aql 5163 44 3.790 0.060 -0.100 0.030 Valenti 2005ApJS..159..141V 38 bet_Aql 5250 3.790 -0.150 Edvardsson 1988A&A...190..148E 38 bet_Aql 5478 1.300 0.200 Luck 1981ApJ...245.1018L 40 eta_Cep 4383 0.130 Herbig 1966AnAp...29..593H 40 eta_Cep 4755 3.000 -0.500 Cottrell 1986A&A...161..314C 40 eta_Cep 4858 8 Kovtyukh 2006MNRAS.371..879K 40 eta_Cep 4907 54 Ramirez 2005ApJ...626..446R 40 eta_Cep 4908 56 Alonso 1999A&AS..139..335A 40 eta_Cep 4915 di Benedetto 1998A&A...339..858D 40 eta_Cep 4920 61 3.290 0.150 -0.140 0.050 da Silva 2011A&A...526A..71D 40 eta_Cep 4950 3.410 -0.320 McWilliam 1990ApJS...74.1075M 40 eta_Cep 4971 412 3.540 0.180 -0.140 0.070 Allende Prieto 2004A&A...420..183A 40 eta_Cep 4985 3.450 -0.180 Hekker 2007A&A...475.1003H 40 eta_Cep 4990 3.400 -0.140 Fuhrmann 2004AN....325....3F 40 eta_Cep 5040 2.950 -0.120 Van Paradijs 1973A&A....23..369V 40 eta_Cep 5040 3.150 0.230 Gratton 1982MNRAS.201..807G 40 eta_Cep 5080 137 3.660 0.220 -0.120 0.140 Affer 2005A&A...433..647A 40 eta_Cep 5100 3.500 -0.070 Luck 2006AJ....131.3069L 40 eta_Cep 5100 3.500 -0.070 0.070 Luck 2005AJ....129.1063L 40 eta_Cep 5150 3.400 -0.060 Mishenina 2003ARep...47..422M 40 eta_Cep 5152 394 Gonzalez Hernandez 2009A&A...497..497G 41 gam_Cep 4383 0.270 Herbig 1966AnAp...29..593H 41 gam_Cep 4421 -0.040 Bakos 1971JRASC..65..222B 41 gam_Cep 4625 94 3.470 0.200 0.200 0.150 Allende Prieto 2004A&A...420..183A 41 gam_Cep 4650 2.350 -0.020 Luck 1995AJ....110.2968L 41 gam_Cep 4727 3.000 0.000 0.090 Ramirez 2007A&A...465..271R 41 gam_Cep 4770 3.270 0.000 McWilliam 1990ApJS...74.1075M 41 gam_Cep 4810 3.000 0.040 Mishenina 1995A&AS..113..333M 41 gam_Cep 4846 2.770 -0.040 Gratton 1982MNRAS.201..807G 41 gam_Cep 4875 138 3.230 0.270 0.050 0.070 da Silva 2011A&A...526A..71D 41 gam_Cep 4888 3.330 0.180 Fuhrmann 2004AN....325....3F 41 gam_Cep 4916 70 3.360 0.210 0.160 0.080 Santos 2004A&A...415.1153S 41 gam_Cep 4935 139 3.630 0.380 0.140 0.190 Affer 2005A&A...433..647A 41 gam_Cep 4970 64 Ramirez 2005ApJ...626..446R 41 gam_Cep 5015 3.490 0.260 Luck 2006AJ....131.3069L 41 gam_Cep 5015 3.490 0.260 0.110 Luck 2005AJ....129.1063L 41 gam_Cep 5091 3.570 -0.050 Lambert 1981ApJ...248..228L