Eruption of the Recurrent Nova RS Oph!

[robin_astro]

RS Oph is entering an interesting new phase not seen in typical novae as the explosion crashes into the material surrounding the red giant, producing a shock wave which heats the material to very high temperatures. This produces highly ionised "coronal lines" in the spectrum, for example [Fe X] (Iron with 9 electron knocked out of it) shown here.  (Note the Y scale has been stretched massively to show these weaker lines. The peak intensity of the alpha line is well over 100 !).

 I saw the same line appear in spectra taken around the same time during the previous outburst back in March 2006 Using a Star Analyser grating

http://www.threehillsobservatory.co.uk/astro/spectra_24.htm

 

[Martin Meredith]

Here's a quick capture from a couple of hours ago. N up. Live LRGB combination of 2s subs. This is with saturation at minimum (otherwise the red was at the unbelievable end of garish...).

Martin 

[lunator]

RS Ophiuchi
Using  the 25mm (x16), first impression – no colour.
Used the 12.5mm to darken the sky background a little more.
It is quite faint now. 
Fainter than HD162488 (7.98)
Similar in brightness to HD162215 (9.68) & HD162369 (9.56)
Brighter than HD162449 (9.81)
I estimated the Magnitude at 9.6.

I have enjoyed following this event. Although the OMC250 may have to be used more now

cheers

Ian 
 

[lunator]

It has faded a bit more now.

I estimated it to be Mag 9.7

It is quite handy having similar magnitude stars nearby to compare to.

Cheers

Ian

[Malpi12]

Yes, very faint, almost beyond my capability with a 50mm lens on a tripod.
Yesterday 20Sep, a race between dusk and it going behind a tree not helped by some thin haze and drifting thin clouds, surprised I got anything! A quick 40x2sec, DSS + a lot of stretch in Gimp but no added saturation, still a nice ruby red.

[JeremyS]

Declining, but not back at quiescence minimum yet

[lunator]

RS Oph plot.docx

Here is my plot. 

There did seem to be a plateau for about 5 days from the 23/08.

Cheers

Ian

[lunator]

This my plot as a jpg as not everyone will have excel. The gaps really show where the weather and work get in the way

Cheers

Ian

[sirenity]

I’m a total newbie so this is probably wrong but just spotted something close to where it would be, naked eye quite red and twinkling like a mad thing (when nothing around it was so not just weather). Took a good while to be convinced it was a not plane coming straight towards me. I know it was active in August as well and hadn’t been for years before, could it be going again? 

Clouded over now and close to horizon so I don’t think I’ll have a chance to see again tonight. 

[robin_astro]

19 hours ago, sirenity said:

naked eye quite red and twinkling like a mad thing

Arcturus perhaps ?  Bright, orange  almost directly West (rather than SW for Ophiuchus) after dark currently. Low in the sky so twinkling due to the thickness of atmosphere we are looking through

Cheers

Robin

[JeremyS]

Still not quite back at quiescence yet

[lunator]

I had a look last night and it appeared about Mag 10.4.

Cheers

Ian