medium resolution spectra around H-Alpha taken from 23Tau
On January 24th, 2022, I got the chance to perform some observations. One of the targets was 23Tau. I performed a spectra in medium resolution around the H-Alpha line.
23 Tau, better known under it's name Merope as member of the Plejaden star cluster is a Be-Star which shows in H-Alpha an emission line.
According to Gaia-Mission Merope is one of the closest star from this open cluster. it's a subgiant of spectral class B resulting in a luminosity of about 600 times of our sun. Driven by the distance it's appearent brightness is about 4 magnitudes. Merope shows a small variability of Beta Chephei type with an amplitude of just 0.01 magnitudes.
This spectra shows the typical self absorbtion feature which well known for Be-stars and read as indication for a hydrogen disc around the star. To analyse details a model for the disc has to be performed and radiative transfer calculation are required. Currently I'm not having such kind of software, but I'm working on this issue. Potential changes of the line profile during several months makes Be-star to a worthwhile target for observations.
S/N achieved is about 550. The spectral resolution R dereived from calibration spectra is just about R = 5000 only. The linear resolution is 0.0256nm / pixel.
Thank you to the Astronomie Stiftung Trebur for using their ST10-XME CCD.