Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

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Affiliated to the Astrophysics Division, Space Science Department of ESA.

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... emission

For about 75% of the $\ensuremath {{\rm H}\alpha }$ emission stars the effective temperatures determined with or without the F300W band differ by less than 5%. For the remaining 25% of the objects, though, the mean difference in ${T}_{\rm eff}$ is 20%, in the sense that the fit including the F300W band returns higher values, with a maximum discrepancy of about 40% for the stars with the strongest Balmer continuum excesses.

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