Emission Line Stars


Approximately 50 known B[e] stars from the subtypes (supergiants, pre-main-sequence, compact planetary nebulae, symbiotic stars) are observed to provide templates for B[e] stars serendipitously discovered by APOGEE.

Finding Targets

An object whose APOGEE_TARGET2 value includes one or more of the bitmasks in the following table was targeted for spectroscopy as part of this ancillary target program. See SDSS bitmasks to learn how to use these values to identify objects in this ancillary target program.

APOGEE_TARGET2 bit name Bit Target Description
APOGEE_EMISSION_STAR 15 Emission-line star


APOGEE has observed a small number of B[e] stars serendipitously among its telluric standards. However, diagnosing the evolutionary state of these stars is difficult in the absence of H-band spectra of known B[e] stars. To produce the first high-resolution, near-IR spectral atlas of B[e] stars, this program targets about 50 well-studied B[e] stars among the sub-classes: 1) B[e] supergiants; (2) pre-main sequence Herbig B[e] stars; (3) compact planetary nebulae; (4) and symbiotic B[e] stars (Lamers et al. 1998). The separate spectra taken during the multiple visits in the APOGEE observing strategy will be used to help identify binary systems. In addition, the presence of multiple hydrogen (Brackett) lines in the H-band make studies of reddening toward B[e] stars possible. Assuming that departures from Case B recombination line ratios are due to interstellar dust, a large B[e] star sample across the Milky Way can be used to test the hypothesis (Zasowski et al. 2009) that extinction is dependent on Galactocentric radius.

Primary contacts

Drew Chojnowski
New Mexico State University

Other contacts

David Whelan, David Nidever, Fred Hearty

Target Selection Details

Well-studied B[e] stars lying in the APOGEE fields to be observed in the latter half of the survey with 10 < H < 12 were targeted


Lamers, H. et al. 1998, A&A, 340, 117
Zasowski, G. et al. 2009, ApJ, 707, 510