Thursday, December 05, 2019

found more Miram companions

While I was reviewing and updating double star data for the RASC programme, something caught my eye about Miram aka η Persei aka Σ307. More stars.

It is a septuple system. There are (currently) 7 visible stars in this system.

I re-read my logs.

From the section 2 of 2 of my lift list, I noted I had first viewed the double in October 2011. Following Haas's lead, I thought it a pair.

Later I learned it was a quad. However a session in February 2013 did not serve up the C and D stars. So it made it's way to my "view again" list.

I had a go with the imaging rig in Halifax. Captured photons in September 2016 and a week later assembled an LRGB image. Colourful!

And, I accomplished my prime mission. I sussed out the C and D stars, faint little things, close to each other, to the west.

As I re-examined the black-and-white and colour images, I noted lots of stars. And that made me wonder if I hadn't captured these "new" or extra stars, some of the seven.

Checked the WDS data via in Stella Doppie. The 02507+5554 system components are:

STF 307AB177920185630128.73.768.5
STF 307AC1878201414269643.7611.61
SHJ 34AE192520128297242.93.769.24
WAL 19AF1904201372557.73.7611.44
WRD 1CD18782015141165.211.6112.7
FYM 161CG20032015622915.811.6114

Loaded the component codes, the PAs, and the Seps into my updated Excel modeller.

multiple star Miram plotted up to G star

Wow. My new plotter version was working well is the indirect references.

Anyhoo, the great news was that in addition to A, B, C, and D tagged earlier, now I had identified a few more elements.

E (aka SHJ 34) is the bright blue-white star beyond B, maybe 9 or 10 times the AB separation. Is the position angle the same? It's very close to that angle. The star is a touch dimmer than B. But I think the exact same colour.

F (WAL 19) is the dull yellow star to the north-north east. Slightly closer than CD.

And finally G. Crazy G. aka FYM 161. It is an extremely faint star south-west from C, 3 or 4 times the CD separation. Hard to get a colour. A fairly new discovery, from 2003.

How about that. Three more items tagged. Just by going through old data! So I'm very happy about that.

Still. It is very curious to me that there are still more stars buzzing around Miram A... Why have they not be included?! Strange.

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