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R Aqr Eclipse - Monitoring requested

Posted: Fri Jul 12, 2019 8:54 pm
by Francois Teyssier
R Aqr could be in eclipse according to the luminosity of the system near the maximum of the pulsation.
Margarita Karovska (Center for Astrophysics | Harvard & Smithsonian) request spectroscopic monitoring (low and high res) as soon as possible.

François

Re: R Aqr Eclipse - Monitoring requested

Posted: Fri Jul 12, 2019 9:41 pm
by Francois Teyssier
The historical light curve in AAVSO database (Visual, 15 days mean)
since 1908
RAqr_Histo.PNG
RAqr_Histo.PNG (22.87 KiB) Viewed 23564 times
The 3 last pulsations of the Mira
RAqr.PNG
RAqr.PNG (4.8 KiB) Viewed 23564 times
with the recent maximum about 1 mag under the previous ones.

Re: R Aqr Eclipse - Monitoring requested

Posted: Tue Jul 30, 2019 4:46 am
by Francois Teyssier
Echelle spectrum obtained this morning.

Emission lines looks weaker than during the previous pulsations of the mira at about the same luminosity

Na I D in emission.
raqr-comp.png
raqr-comp.png (18.77 KiB) Viewed 23475 times

Re: R Aqr Eclipse - Monitoring requested

Posted: Wed Aug 28, 2019 12:07 pm
by Francisco Campos
Hello,

after a long stop due to lack of time to observe, two days ago I could obtain some spectra. Here is a low resolution spectrum of R Aqr compared wiht another taken a year ago. More or less both spectra are taken in the same pulsation phase. The main difference is in the Mira intensity: the continuum is weaker as expected, but I don't appreciate more differences.
raqr_ 20190825_960_FPC.png
When I have finished processing the remaining spectra, I will upload them into the database.

Best regards,
Fran

Re: R Aqr Eclipse - Monitoring requested

Posted: Wed Sep 11, 2019 9:08 pm
by Francois Teyssier
The target is now easy during the nights, but its luminosity declines.
The phase (pulsation) is ~ 0.2 and it will be easier to compare the spectra with those of previous cycles.
RAqr.PNG
RAqr.PNG (17.26 KiB) Viewed 23058 times

Re: R Aqr Eclipse - Monitoring requested

Posted: Fri Oct 18, 2019 4:30 am
by Francois Teyssier
The luminosity of the current pulse remains much lower in comparison to previous pulses

Significant changes of the main lines, EW and profile, especailly in the blue part of the lines:

Tim lester's spectra R = 140000
RAqr_LC.PNG
RAqr_LC.PNG (17.32 KiB) Viewed 22741 times
Hac.png
Hac.png (22.19 KiB) Viewed 22741 times
OI6363.png
OI6363.png (18.49 KiB) Viewed 22741 times
NII5754.png
NII5754.png (17.66 KiB) Viewed 22741 times
Margarita Karovska:
There it is definitely something going now...
Let see how the spectrum changes in the next couple of months.

and suggest: Can you do weekly spectroscopy?

HST and CHANDRA observations scheduled

Posted: Sat Jan 04, 2020 5:38 am
by Francois Teyssier
Margarita Karovska informs:

The R Aqr DDT HST observations are scheduled now for January 13th and 14th, and the Chandra for the week of January 13th.

So spectroscopic observations a couple of time a week between now and Jan 12, and then good cover of the 13th, 14th and that week, will be great.

"Fluxed" spectra will be of a great help!

Any possibility for a high speed photometry/spectroscopy?

High cadency spectroscopy is strongly recommended from now and especially on 13th and 14th.


The Mira is at its faintest luminosity, near phase 0.5.
RAqr.PNG
RAqr.PNG (17.81 KiB) Viewed 22288 times
Last spectrum in the database obtained by Woody Sims
asdb_raqr_20200101_071.png
asdb_raqr_20200101_071.png (11.6 KiB) Viewed 22288 times

François Teyssier
David Boyd
Woody Sims

Re: R Aqr Eclipse - Monitoring requested

Posted: Sat Jan 04, 2020 8:26 am
by Hamish Barker
any recommendation for reference star selections nearby?

Re: R Aqr Eclipse - Monitoring requested

Posted: Sun Jan 05, 2020 10:13 pm
by Forrest Sims
Hello Hamish,

I will throw this idea out in answer to your question. I have been using HD192907 as the Reference star. Because R Aqr is setting so early I take its spectrum first, followed by the Reference star. HD192907 is a Miles Reference star in ISIS. Other helpful factors are that it is a B9III star and an E(B-V) = 0.02. The airmass at the time I shoot the Reference star is pretty close to that at the midpoint of the R Aqr exposures. HD192907 is also on the same side of the pier as the target. Possible disadvantages are that it is pretty bright at mag 4.395, which depending on your system might mean pretty short exposures and is Northwest whereas the target is Southwest so the airmass may be somewhat different. Other possible Reference stars I have considered get too far away from a late B to an early A star and or have really bad E(B-V) value exceeding 0.05. Maybe this will spark some discussion and we can come up with a better option.

Here is my spectrum of R Aqr from last night.

Woody Sims

Re: R Aqr Eclipse - Monitoring requested

Posted: Fri Jan 10, 2020 11:14 pm
by James Foster
This is probably the last spectra I'll take of this star until late summer, but here is a visual (04Jan20) spectra of R Aqr:
Image
The visual continuum is almost flat with respect the the intense OIII and Ne lines. All other other (except the Ne5754A line) are speculative.

James

p.s. Woody, your spectrum seems more resolved than mine around H-Alpha, but mine may be better resolved at λ<4000A lines.