L8V
Kirkpatrick99 standard: 2MASSW J1632291+190441 - L8V
Hawley02 standard: 2MASS 1632+1904 - L8V
Kirkpatrick05 standard: 2MASSW J1632291+190441 - L8V ("optical anchor")
Reid08 standard: 2MASS J16322911+1904407 - L8 (pri. stan.)
2MASS J02550357-4700509 (DENIS-P J0255-4700) - L8 (sec. stan.)
Kirkpatrick09(GrayCorbally): 2MASS J16322911+1904407 - L8 (primary optical standard)
Kirkpatrick10 standard: 2MASS J16322911+1904407 - L8V (primary near-IR standard)
Kirkpatrick09 writes "The optical L-dwarf sequence presently ends at
L8; there are no objects yet identified with optical types of L8.5, L9,
L9.5. Just beyond L8 there is an abrupt change in spectral morphology
in the optical leading to the cooler dwarfs of type T."
Teff(L8V) = 1300 K ; Cifuentes20 for CARMENES L8V(N=3)
Teff(L8V) = 1336 K ; Kirkpatrick20 (Table 13 polynomial)
Teff(L8V) = 1337 K ; Filippazzo15 calibration (M6V-T9V)
Teff(L8V) = 1367 K ; Dupuy17(SaumonMarley08 model scale)
Teff(L8V) = 1417 K ; Rad vs. logL for BT-Settl 3Gyr [M/H]=0 isochrone for LogL=-4.552
Teff(L8V) = 1451 K ; Dupuy17(Lyon model scale)
=> adopt Teff(L8V) = 1420 K (logT = 3.152) [updated 4/17/2020]
(V-Rc)(L8V) = 3.02 ; DEN J0255 (see below)
(R-I)(L8V) = 2.440 ; star #142 (J1632+1904) of Liebert06
(R-I)(L8V) = 2.827 ; star #25 (J0255-4700) of Liebert06
=> adopt (R-I)(L8V) = 2.634
(V-Ic)(L8V) = 5.47 ; DEN J0255 (see below)
(V-J)(L8V) = 9.68 ; DEN J0255 (see below)
(V-H)(L8V) = 10.72 ; DEN J0255 (see below)
(V-Ks)(L8V) = 11.36 ; DEN J0255 (see below)
(L8V) = 1.77 ; Faherty09
M_G(L8V) = 19.548 ; Reyle18 polynomial
(G-Rp)(L8V) = 1.880 ; Reyle18 polynomial
(G-J)(L8V) = 5.547 ; Reyle18 polynomial
(J-Ks)(L8V) = 1.705 ; Reyle18 polynomial
(J-H)(L8V) = 1.164 (+-0.13 rms) ; SIMBAD trend for d<30pc L dwarfs
=> adopt (J-H)(L8V) = 1.16 [updated 8/6/2020]
(H-Ks)(L8V)= 0.625 (+-0.09 rms); trend SIMBAD d<30pc L dwarfs
=> adopt (H-Ks)(L8V) = 0.625 [updated 8/6/2020]
(Ks-W1)(L8V) = 0.847 ; Dupuy12 median N=8 d<50pc
(Ks-W1)(L8V) = 0.843 ; Dupuy12 trend
=> adopt (Ks-W1)(L8V) = 0.845 [updated 12/28/2019]
M_J(L8V) = 14.094 ; Reyle18 polynomial
M_J(L8V) = 14.649 ; EEM fit to L/T dwarfs d<25pc
M_J(L8V) = 14.952 ; pri. stan. 2MASS J16322911+1904407
=> adopt M_J(L8V) = 14.65 [updated 12/30/2020]
M_H(L8V) = 13.239 ; Reyle18 polynomial
M_H(L8V) = 13.697 ; pri. stan. 2MASS J16322911+1904407
M_K(MKO)(L8V)=12.963 ; 2MASS_0859-1949 8.0 calc using Kirkpatrick20 (plx=71.22mas)
M_Ks(L8V)= 12.2234 ; SDSS_0857+5708 8.0 calc using Kirkpatrick20 (plx=71.2343mas)
M_Ks(L8V)= 12.4763 ; WISE_0031+5749 8.0 calc using Kirkpatrick20 (plx=71.0mas)
M_Ks(L8V)= 12.703 ; Reyle18 polynomial
M_Ks(L8V)= 12.74 ; fit to Kirkpatrick20 L7-T3 dwarfs d<25pc (12/2020)
M_Ks(L8V)= 12.75 ; trend to L/T dwarfs in notes (1/2021)
M_Ks(L8V)= 12.875 ; WISE_0807+4130 8.0 calc using Kirkpatrick20 (plx=50.7mas)
M_Ks(L8V)= 12.9042 ; WISE_0643-0223 8.0 calc using Kirkpatrick20 (plx=71.9172mas)
M_Ks(L8V)= 12.915 ; median nearest 10 L8s SIMBAD
M_Ks(L8V)= 12.973 ; 2MASS_0859-1949 8.0 calc using Kirkpatrick20 (plx=71.22mas)
M_Ks(L8V)= 13.088 ; pri. stan. 2MASS J16322911+1904407 (plx = 65.60+-2.10mas)
M_Ks(L8V)= 13.1539 ; 2MASS_0645-6646 8.0 calc using Kirkpatrick20 (plx=53.8mas)
M_Ks(L8V)= 13.1543 ; SIMP_1132-3809 8.0 calc using Kirkpatrick20 (plx=59.0mas)
=> adopt M_Ks(L8V) = 12.74 [updated 12/30/2020]
Mv(L8V) = 24.44+-0.13 ; DEN J0255 (see below)
BC_K(L8V) = 3.196 mag ; Golimowksi04
BC_Ks(L8V) = 3.227 mag ; Filipazzo15 (field)
BC_Ks(L8V) = 3.216 mag ; Looper08
BC_Ks(L8V) = 3.35 mag ; Schmidt14 (N=1)
=> adopt BC_Ks(L8V) = 3.22 [updated 11/1/2019]
logL(L8V) = -4.552 ; M_Ks=12.9, BC_Ks=3.22, Mbol=16.120
=> adopt logL(L8V) = -4.552 [updated 4/17/2020]
=> adopt Mbol(L8V) = 16.120 [updated 4/17/2020]
Rad(L8V) = 0.08751 ; logL=-4.552, Teff=1420K
=> adopt Rad(L8V) = 0.0875 Rsun [updated 4/17/2020]
# Primary Standard
2MASS J16322911+1904407 = 2MASSW J1632291+190441
*L8: Kirkipatrick99(L8V),Hawley02,Kirkpatrick05(opt.anchor),Reid08(pri.stan.),Kirkpatrick09(pri.opt.stan.),Kirkpatrick10(pri.near-IR.stan.)
This was the coolest/reddest L dwarf (not showing methane) in
Kirkpatrick99 paper defining the L sequence, and Kirkpatrick99 sets
it as the L8 optical standard, and Kirkpatrick10 sets it as the L8
near-IR standard. Unfortunately it was too faint to be detected in
any of the Gaia catalogs. plx=65.60+-2.10mas(Dahn02). J=15.867+-0.070,
H=14.612+-0.038, Ks=14.003+-0.047. M_J=14.952+-0.099,
M_H=13.697+-0.079, M_Ks=13.088+-0.084. Does not appear in Gaia DR3.
# Examples
DENIS J025503.3-470049 = 2MASS J02550357-4700509
L8: Cruz03,Cruz07,Kirkpatrick08
L8(opt): Burgasser10
L9(IR): Burgasser10
L7.5: Costa06
plx=201.37+-3.89mas(Costa06), d=4.79+-0.10pc(Costa06),
V=22.921+-0.121(Costa06), Rc=19.906+-0.039(Costa06),
Rc=20.062+-0.033(Liebert06), Ic=17.235+-0.011(Liebert06),
Ic=17.454+-0.031(Costa06), Y=14.32+-0.10(Leggett10),
J=13.246+-0.027(2M), H=12.204+-0.024(2M), Ks=11.558+-0.024(2M),
Rc-Ic=2.827(Liebert06), J-K=1.69+-0.04(Burgasser10),
V-J=9.675+-0.139(Costa06,2M), V-H=10.717+-0.138(Costa06,2M),
V-Rc=3.015+-0.0142, V-Ic=5.467+-0.140, V-Ks =
11.362+-0.138(Costa06,2M). Costa06 says it is "the closest known
L dwarf... with Mv = 24.44, the faintest dwarf with a measured
absolute visual magnitude." Lum = 0.00010140 Lsun (Ardila10) =>
logL = -3.994. Mv = 24.44+-0.13 (using Costa06 #s).
# Comments on end of L sequence, defining L8V
Notes by Kirkpatrick99 on setting 2MASSW J1632291+190441 to be L8V -
end of L sequence (at least as of 1999): "It should be noted here that
the search for infrared-selected QSOs (Cutri et al. 1999) has
identiĆed candidates over a larger area of sky than that surveyed here
(~1900 deg2, or roughly 5 times as much coverage as our survey), and
only seven additional IR-only sources with J-Ks > 2.00 beyond those
listed in Tables 2 and 3 were found. All of these have been observed
spectroscopically, and none of the confirmed L dwarfs are cooler than
the coolest shown in this paper. Because of the much larger area of
the QSO search and its lack of success in uncovering redder L dwarfs,
we believe that we already have objects near the breakpoint between
classes L and T. In other words, objects with temperatures cooler
than 2MASSW J1632291]190441 will have J-Ks colors less than ~2.00 or
perhaps considerably less than ~2.00 depending upon how quickly the
onset of methane absorption occurs with temperature. However, to leave
room for additional L types in case cooler non- methane objects are
discovered, we will set the spectral type of 2MASSW J1632291+190441 to
be L8 V." Kirkpatrick10 also adopted 2MASS J16322911+1904407 as the L8
near-IR standard.