Search found 164 matches

by David Boyd
Sun Oct 27, 2024 2:28 pm
Forum: Spectra, results, information on activity ...
Topic: Comet C/2023 A3 (Tsuchinshan-Atlas)
Replies: 3
Views: 5188

Re: Comet C/2023 A3 (Tsuchinshan-Atlas)

Spectral image and resulting spectrum of C/2023 A3 recorded on 17th October with a LISA spectroscope on a C11 scope. During 40 mins of integration the comet dropped in altitude from ~24 deg to ~16 deg. The spectrum was response corrected with a spectrum of the B9.5III star HD149121 recorded at an ...
by David Boyd
Wed Aug 07, 2024 8:42 am
Forum: Novae
Topic: Nova Vul 2024 July, 2024
Replies: 9
Views: 14080

Re: Nova Vul 2024 July, 2024

Hello,
Recent evolution of Nova Vul 2024 at low resolution. C-11 + LISA, R~1100, flux-calibrated with concurrent V-band photometry.
David
novavul2024_20240801_927_D_Boyd.png
novavul2024_20240801_927_D_Boyd.png (41.64 KiB) Viewed 13947 times
novavul2024_20240801_927_D_Boyd H-beta.png
novavul2024_20240801_927_D_Boyd H-beta.png (27.64 KiB) Viewed 13947 times
novavul2024_20240801_927_D_Boyd H-alpha.png
novavul2024_20240801_927_D_Boyd H-alpha.png (26.94 KiB) Viewed 13947 times
by David Boyd
Tue Jan 16, 2024 9:16 am
Forum: Spectroscopes and Softwares
Topic: Wavelength Calibration Relco
Replies: 6
Views: 46064

Re: Wavelength Calibration Relco

Hi Francois,

Yes, good to be back. :-)

I use a LISA on a C11. I now use the following 22 lines from the LISA Ar/Ne lamp in a .lst file with a 4th order polynomial. This typically gives an rms in ISIS of around 0.08 and a resolving power of about 1100.

4
1.8
7383.980
7272.936
7147.042
7067.218 ...
by David Boyd
Wed Feb 08, 2023 5:10 pm
Forum: Comets
Topic: La Comète du début de l'année : C/2022 E3
Replies: 18
Views: 26255

Re: La Comète du début de l'année : C/2022 E3

A spectrum of C/2022 E3 ZTF taken on 6th February with a LISA spectrograph on C11 scope. Emission features tentatively identified.
David
c2022e3_20230206_822_D_Boyd.png
c2022e3_20230206_822_D_Boyd.png (36.24 KiB) Viewed 12906 times
by David Boyd
Tue Feb 07, 2023 4:57 pm
Forum: Cataclysmic Stars
Topic: GK Per Outburst
Replies: 22
Views: 32743

Re: GK Per Outburst

Another spectrum of GK Per as it slowly fades. This was calibrated in absolute flux with a concurrently measured mean V magnitude of 10.95.
David
gkper_20230205_810_D_Boyd.png
gkper_20230205_810_D_Boyd.png (41.65 KiB) Viewed 10123 times
by David Boyd
Tue Jan 24, 2023 11:41 am
Forum: Cataclysmic Stars
Topic: GK Per Outburst
Replies: 22
Views: 32743

Re: GK Per Outburst

Hello Hubert,

Yes, these are different processes. Flickering is intrinsic in the accretion process in a CV while scintillation is an atmospheric phenomenon. There is a useful source of data on scintillation at http://astro.corlan.net/gcx/scint.txt. This shows that scintillation varies strongly with ...
by David Boyd
Mon Jan 23, 2023 6:29 pm
Forum: Cataclysmic Stars
Topic: GK Per Outburst
Replies: 22
Views: 32743

Re: GK Per Outburst

Hello Hubert,

According to Bruch, A&A, 266, 237 (1992) the mean B-V colour index of the flickering light source in GK Per is close to 0 so the B and V magnitudes should change together, subject to the stochastic variation inherent in the flickering process.

The exposures were alternately 10 sec in ...
by David Boyd
Sun Jan 22, 2023 12:36 pm
Forum: Cataclysmic Stars
Topic: GK Per Outburst
Replies: 22
Views: 32743

Re: GK Per Outburst

Here is another spectrum of GK Per taken on 20th January and calibrated in absolute flux using concurrently measured V magnitudes with a mean of V = 10.96.

gkper_20230120_842_D_Boyd.png

I continued to record B and V magnitudes for 1.4 hrs while recording the spectra and the resulting light ...
by David Boyd
Sun Jan 15, 2023 8:46 am
Forum: Cataclysmic Stars
Topic: GK Per Outburst
Replies: 22
Views: 32743

Re: GK Per Outburst

Another spectrum of GK Per taken with a LISA (R~1000) and flux calibrated using a V magnitude concurrently recorded by Franky Dubois (AAVSO AID).

David
gkper_20230113_782_D_Boyd.png
gkper_20230113_782_D_Boyd.png (26.46 KiB) Viewed 13056 times
by David Boyd
Thu Sep 01, 2022 11:27 am
Forum: Symbiotic Stars
Topic: Suspected/Misclassified Symbiotics: spectra required
Replies: 128
Views: 3982999

Re: Suspected/Misclassified Symbiotics: spectra required

Guider image of OY Cyg
OY Cyg guider image.png
OY Cyg guider image.png (20.97 KiB) Viewed 19109 times
Spectrum of OY Cyg
OY Cyg.png
OY Cyg.png (35.48 KiB) Viewed 19109 times
Looks like a M6III - M7III spectrum.

David