Does anyone own a spectrograph and is available to observe a possible Lambda Bootis star's metalic lines? The star has the magnitude 5.2 in V.
According to Gray and Corbally (P192-199) As well as generally being of low metallicity, among other characteristics, Lamda Boo stars are best characterised by their low Mg II 4481/Fe 4383 line ratio which is significantly lower than in normal A type stars
Here is the archetype Lamda Boo at an SNR of 420 in the ELODIE archive.
I suspect a very high SNR may be needed to measure the metal lines which are already weak in A stars anyway
The star I'm talking about is Galati V22 in the VSX. It's an A4Vp spectral type (p stands for peculiarity). I didn't find any available spectra on the internet, that's why I'm asking for data
A quick look in VizieR and SIMBAD suggests that the most recent spectral classification remains that of Helmet Abt and Nidia Morrell (1995ApJS...99..135A), who call it A5Vp, noting weak MgII 4481A. The MgII weakness is a necessary but not sufficient condition for being a lambda Boo star. But it is a candidate, as you suggest.
A good summary of what's required for lambda Boo-ness is Simon Murphy et al.'s very nice summary, accessible here:
They obtained new spectra with resolution of roughly 2A per pixel-pair and high S/N to classify the stars. (HD 46089 is not included.) So that is what will be required for someone to do this in a dispositive way.
Sounds great. If you can get the imporant region between 3900A and 4500A (between H&K and the MgII line at 4481A), that will probably do the trick. I suppose Simon Murphy (or Richard Gray or Father Corbally) would like to see the spectrum, too, in case it is interesting to them!
Of course. Timing is very weather dependent, particularly at this time of year (This year has been very poor in this already cloudy corner of England) It is well placed for the next few months though.
I had a brief window of clear sky last night so took a look at this star. The spectrum covers 4200-4550A at ~3A rescolution. A second spectrum covers the Ca K line at much lower (~10A) resolution due to the spectrograph achromatic optics. The spectra are compared with bet Leo taken the same night, A3v, the same reference as Gray and Corbally p 195 fig 5.20. ( I planned to attach figures showing a comparison of the rectified spectra but I can no longer see the facility to add attachments. Has it been removed ? If so I will try to find somewhere to upload them and add a link)
The spectrum of HD46089 is almost identical to that of bet Leo with only marginally weak Mg 4481 and no obvious reduced metallicity. Although noisy and low resolution, the spectra also look similar around the Ca K line (Though there does appear to be a curious additional feature on the blue edge of the Ca K line in the HD46089 spectrum which might warrant investigation at higher resolution.)
The spectrum (1D fits) is available for download from the BAA database.
Please note the conditions of use