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HR 8752
https://forum.vdsastro.de/viewtopic.php?t=5037		 Seite 1 von 1
Autor:  Andrew Smith [ 17. Dezember 2017, 14:18:44 PM ]
Betreff des Beitrags:  HR 8752
Here are two rectified spectra of HR 8752 taken recently with my MRes spectrograph. They are as observed with no wavelength correction.

There is strong emission compared to the historic spectra I have found. In addition to H alpha there is strong emission from N II at 6582 (identified via the literature).

Any advise on identifying other lines welcome.

Regards Andrew
Dateianhang:
hr8752_20171211_776_SAJB.png
hr8752_20171211_776_SAJB.png [ 35.77 KiB | 2037 mal betrachtet ]
Autor:  Otmar Stahl [ 18. Dezember 2017, 13:26:49 PM ]
Betreff des Beitrags:  Re: HR 8752
Hi Andrew,
Zitat:
Here are two rectified spectra of HR 8752 taken recently with my MRes spectrograph. They are as observed with no wavelength correction.

There is strong emission compared to the historic spectra I have found. In addition to H alpha there is strong emission from N II at 6582 (identified via the literature).

Any advise on identifying other lines welcome.

Regards Andrew
I checked the Elodie database. The database contains a spectrum with similar emission line strength from 1996:

http://atlas.obs-hp.fr/elodie/index.html?HD217476

Concerning the identification of the other lines: The [NII]6548 line is expected with 1/3 of the strength of the [NII]6582 lines.. It is clearly present. I think there is also FeII6516. For the other lines, comparison with a solar atlas would help to identify the lines. These are probably lines from neutral or singly ionized metals, e.g. FeI and FeII.

Best regards,
Otmar
Autor:  Andrew Smith [ 19. Dezember 2017, 14:36:52 PM ]
Betreff des Beitrags:  Re: HR 8752
Thanks for the reply Otmar.

I had looked at the Elodie spectra and thought they were different in some ways. Maybe it is due to the different resolution - see attached.
Dateianhang:
hr8752_SAJB_v_Elodie.png
hr8752_SAJB_v_Elodie.png [ 34.66 KiB | 1987 mal betrachtet ]
I measured the Equivalent Width of the N II line at 6582 and got 0.465 A for the Elodie spectra and 0.530 A using SPLAT-VO and a Gaussian fit with a fitting error of about 0.01 in both cases. I used my rectified spectra and normalised a region close to the line to 1 in the Elodie spectra.

Also thanks for the advice on the lines.

Regards Andrew
Autor:  Otmar Stahl [ 19. Dezember 2017, 14:48:53 PM ]
Betreff des Beitrags:  Re: HR 8752
Hello Andrew,
Zitat:

I had looked at the Elodie spectra and thought they were different in some ways. Maybe it is due to the different resolution - see attached.
Yes, Halpha looks different, but the different resolution may have some effect. You could try to degrade the resolution of the Elodie spectrum to achieve similar resolution in both spectra.

Best regards,
Otmar
Autor:  Andrew Smith [ 19. Dezember 2017, 19:06:08 PM ]
Betreff des Beitrags:  Re: HR 8752
Here is the filtered comparison. I think that this conclusively shows a change Otmar.

Thanks for you help and advice. I now need to collect data for the next 5 to 10 years!

Regards Andrew
Dateianhang:
hr8752_v_Elodie .png
hr8752_v_Elodie .png [ 25.37 KiB | 1974 mal betrachtet ]
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