**Table 3:** Effective temperature at observation as calculated from the BC and spectral characteristics methods (see text for details). The two estimates agree well for most of the objects, exceptions are explained below.
Star	Log $(T_{\rm eff})$
	BC method	Abs. Line method
AG Car (6/5/94)	3.98 $\pm$ 0.03	4.00 $\pm ^{0.04} _{0.05}$
AG Car (10/2/03)	4.25 $\pm$ 0.03	- ²
HR Car (16/3/92)	3.87 $\pm$ 0.05	3.98 $\pm ^{0.02} _{0.03}$
HR Car (10/2/03)	3.92 $\pm$ 0.03	3.95 $\pm ^{0.04} _{0.05}$
$\eta$ Car	-¹	- ²
Hen 3-519	-³	-²
WRA 751	4.47 $\pm$ 0.03	4.40 .. 4.52
P Cyg	-⁷	-²
HD 160529	4.00 $\pm$ 0.03	3.95 $\pm ^{0.04} _{0.05}$
R 40	4.04 $\pm$ 0.08	3.98 $\pm ^{0.03} _{0.04}$
S Dor ⁴	$\ga$ 3.93	3.95 $\pm ^{0.03} _{0.04}$
R 71	4.04 $\pm$ 0.12	4.19 $\pm ^{0.03} _{0.04}$
R 110	4.04 $\pm$ 0.08 ⁸	4.00 $\pm ^{0.02} _{0.03}$
R 116	4.19 $\pm$ 0.04	$\ga$ 4.15 ⁶
R 127	4.29 $\pm$ 0.04	4.13 $\pm ^{0.08} _{0.11}$
R 143	-⁵	3.99 $\pm ^{0.04} _{0.05}$

¹ The poor understanding of the intrinsic brightness of $\eta$ Car means that the BC method does not produce a reliable result.

² The star's spectrum does not contain the diagnostic absorption lines.

³ An insufficient amount of data is available on the star's brightness history and brightness at the time of observation.

⁴ There is disagreement on the star's temperature at minimum and maximum (as stated in vG01), giving two possible values of the star's temperature at observation using the BC method. Also the star's bolometric luminosity probably changes during outbursts (vG01), invalidating the BC method.

⁵ No AAVSO data exists on this object.

⁶ The Si II absorption lines appear to be filled in by emission in this object, so the temperature was determined from the He I line only.

⁷ P Cyg is not presently observed to be variable, therefore the BC method is not applicable.

⁸ R 110 probably does not vary at constant $L_{\rm BOL}$ , and so the BC method is invalid (vG01).

Source LaTeX | All tables | In the text

	1 Introduction
	2 Observations and data reduction
	3 Results
	4 Discussion
	5 Conclusions
	Appendix A: Atlas of early-type supergiants
	References