R Aqr Eclipse - Monitoring requested

[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

[Francois Teyssier]

The historical light curve in AAVSO database (Visual, 15 days mean)
since 1908

RAqr_Histo.PNG (22.87 KiB) Viewed 32782 times

The 3 last pulsations of the Mira

RAqr.PNG (4.8 KiB) Viewed 32782 times

with the recent maximum about 1 mag under the previous ones.

[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 (18.77 KiB) Viewed 32693 times

[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.

When I have finished processing the remaining spectra, I will upload them into the database.

Best regards,
Fran

[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 (17.26 KiB) Viewed 32276 times

[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 (17.32 KiB) Viewed 31959 times

Hac.png (22.19 KiB) Viewed 31959 times

OI6363.png (18.49 KiB) Viewed 31959 times

NII5754.png (17.66 KiB) Viewed 31959 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?

[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 (17.81 KiB) Viewed 31506 times

Last spectrum in the database obtained by Woody Sims

asdb_raqr_20200101_071.png (11.6 KiB) Viewed 31506 times

François Teyssier
David Boyd
Woody Sims

[Hamish Barker]

any recommendation for reference star selections nearby?

[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

[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:

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.