Forum der Vereinigung der Sternfreunde

Hi all! In the following you can find a text on behalf of our colleague Gregor Rauw at Université de Liège. Cheers, Thomas
__________________________

Dear all,

During the MONS Pro/Am campaign in December 2008 - March 2009, several
members of this forum contributed successfully to a monitoring of the Oe
star HD45314 (RA: 06 27 15.8, DEC +14 53 21.2; m_V = 6.62). The data
from this campaign along with other data from our own monitoring and
from astronomical archives allowed us to cover several outbursts of the
star where its emission level increased significantly. The results of
this study were published in A&A in 2015. During the 2014 - 2015 and
2015 - 2016 observing season, the strength of the emission lines of
HD45314 dropped dramatically as illustrated in the attached plot where
it can be seen that the equivalent width of the H-alpha line reached a
historically low level at the end of 2015. In view of this strange
behaviour, the obvious question is what is the current status: did the
star return to its normal emission level or is it still in a low state,
or is it rising towards an outburst? Due to a technical problem, our own
monitoring campaign is currently interrupted and will only resume in
February at the earliest. If any of you could take a few spectra of this
star centered on H-alpha with a spectral resolving power of about 8000
that would help us enormously. There is no need for a very intense time
coverage. Typically one spectrum every two weeks between now and end of
February would be sufficient. Please do not hesitate to contact me if
(rauw - (at) - astro.ulg.ac.be) if you are interested in this project and/or if
you have further questions.

Best wishes,

Gregor Rauw

Hi,Thomas,

I don't know if someone is currently observing this star. My set-up has not enough resolution to meet the requirements of R=8.000, but I tried to obtain one spectrum with the hope that it would be useful. I could improve a bit the resolution, but not more than 5.000-5.500.

If you believe this resolution can be useful, I will continue monitorizing the star until March, when Gregor Rauw could resume their observations.

Greetings
Fran

Hello Fran,

Best wishes for 2017. Thanks for your message and for the HD45314 spectrum. I think your data are fine even though your spectral resolution does not reach 8000. They will certainly be useful to evaluate the equivalent width of H-alpha as to see how it evolves over time. So if you can take a few spectra, they will nicely complement the efforts of some other people in this forum who are also observing the star. Could you please send me your data (either as FITS or ASCII file) to my e-mail address rauw AT astro.ulg.ac.be? Thanks a lot.

Cheers,

Gregor

Hi,

last week I took the following test spectrum with my objective grating setup. Due to bad weather conditions (partly cloudy, 1/2 moon..) the S/N is rather lousy, below 100. Resolution is about 5000. A rough evaluation of the Hα EW yields about 15,7 Å. If of any use, I can provide this (and further) spectra via fits file.

Cheers, Uwe

Hello,

weather forecast is bad for the next days, but I succesfully took some spectra of HD 45314. Here is a comparison of all spectra. I have already sent them to Gregor. Resolution is about R=5.000. Newton 8" f/4.7 (doubled with a Barlow 2X), DADOS 1200 l/mm, Atik 314L+, 5x1200" for each spectrum.

Greetings
Fran

Hi all! Are there still some observers on this star? Cheers, Thomas

Hi Thomas:

I leave a sample of my observations of HD45314, the weather does not permit, spent many nights this February with clouds. I could only make seven observations of this star.

Regards, Joan.