VSX: Is there an "em" spectral type?

arimsiqueira
Affiliation
American Association of Variable Star Observers (AAVSO)
Fri, 12/22/2023 - 22:33

Hello,

When checking in VSX some information about the star CW Cru, one of the targets I monitored recently, I noticed that it is classified as belonging to the "em" spectral class. Is there an "em" spectral class?

Simbad reports it in the B0IIIe C spectral class (Aidelman et al., 2018, Astronomy and Astrophysics, volume 610A, 30-30).

If anyone could comment, please.

Thanks.

Ari

Roy_Axelsen_ARX
Affiliation
Variable Stars South (VSS)
Symbols in the additional nomenclature

I think the following applies: e means emission lines present; m means enhanced metal features.

Roy

Sebastian__Otero
em

Ari, you have posted the same question both to the Spectroscopy and the VSX forums. You are getting different replies in each forum. I recommend posting to one forum only to avoid this.

Let's continue the thread in:

https://www.aavso.org/there-em-spectral-type

Roy, em just means "emission".
When no spectral class is given and only emission lines are reported, you can just find "em".

Cheers,
Sebastian