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I finished observations of the Mizar A spectroscopic binary.
Calibration for the Hα line made on water lines contained in the Earth's atmosphere.
I used LowSpec spectrograph with 1800 grooves/mm reflective holographic grating, APM APO 107/700, QHY163M camera and HEQ5 mount with guiding.
It turned out that the Earth's movement practically compensated for the radial velocity of the Mizar A system.
Based on the analysis, I received the result:
vr = -8.8 km/s
in fact the system is approaching at a radial velocity of -6.3 km/s.
I also determined the phase plot of radial velocities based on my measurements for the Na (together for both lines) and separately for Hα line:
Error is based on half my spectral resolution (0.2 Å/pix corresponds to rv = 10 km/s). Each measurement corresponds to the stack a few images.
The most important purpose of observing this binary system was to record the historical Ca II line (often called as CaK, 3933.66 Å).
The distances in the violet part of the spectrum are almost 2x smaller than the corresponding shifts for the Hα line. This line initiated the discovery of spectroscopically binary systems, and Mizar A was the first discovered system of this type.
These were the spectroscopic observations in the 19th century:
I've made several observations of this line in the last two weeks:
Animation showing the changes in the CaK line based on my observations:
Not only the Ca II is split, but the surrounding lines also, shown below in a wider environment:
Balmer hydrogen lines are becoming more dense as Balmer's gap approaches (3646 Å).
Observation result of the Hα line:
And animation showing the changes in this line:
The Na I doublet was much more difficult to observe, because stars with A spectral type contain very faint lines of this metal:
Animation showing the changes in the sodium doublet:
We received the sodium quartet
1. Alcyone (Eta Tauri, η Tau, 25 Tau) in the Pleiades open cluster, spectral type B7IIIe+A0V+A0V+F2V.
This star is a multiple system, but my goal of observation was the H-alpha profile of the main component:
Horizontal axis scaled to radial velocity:
2. Pleione (28 Tau, BU Tau) also in M45, spectral type B8Vne, variable star, the brightness changes in range: 4.83 - 5.38 V.
This is the faintest star, which I observed with using APO 107/700 & Low Spec spectrograph 1800 l/mm.
It was difficult, but obervation was positive (high gain, exposure time 4 min):
3. Tianguan (Zeta Tauri, ζ Tau), spectral type B1IVe+G8III: (mark ":" according to the VSX database means uncertainty).
This is an eclipsing binary with variability type E/GS+GCAS, period is 133 d. The brightness changes in range: 2.80 - 3.17 V.
4. Cih, Tsih (γ Cas), spectral type B0.5IVpe, variable star with a magnitude range of 1.6 to 3 V:
5. Alnitak (Zeta Orionis, ζ Ori), spectral type O9.5Ibe+B0III. Variable star with a magnitude range of 1.74 to 1.77 V.
Spectral lines have characteristic P Cygni profile, below H-alpha:
Recently I observed profiles of hydrogen Balmer lines in Sirius spectrum with spectral type A. I used LowSpec spectrograph with 1800 l/mm diffraction grating and APO APM 107/700 on HEQ5 mount.
H-delta & H-epsilon:
I had some problems with stacking, so I used the best single frames in analysis.
By Kcks Regulus Star
On the 2nd of July I closed my curtains one night before I went to bed but, before they were shut I noticed a strange multicoloured light flickering low in the sky in the northern celestial hemisphere. I Thought to myself if that is a star it looks amazing. The next night (3rd of July) I decided to take another look at this multicoloured light which was still there, Only this time I used my binoculars, I was seeing blues, greens & reds. We have all seen stars by looking up into the sky but, I have never seen a star create multi colours before. It makes you feel excited inside and you think that no one else can see this until you tell them and share the same experience together. I believe I was looking at the Capella Star which is the brightest star in the constellation Auriga and your not kidding it is bright. I cant wait to have another look tonight to see if the multi colours are still there. I would like to have taken at picture of it but I am not setup to do that just yet as I am very new to star gazing. I wish someone here can confirm what I saw and to post a picture of it would be awesome.
Nikon Prostaff 3s 8 x 42