[ngcles]

Hi §AB & All,

Yes, it is certainly observable.

I stumbled up on this thing about 10 years ago while cruising around in the Megastar (v4.0? back then) software looking for things to look at and marked it for attention.

My first observation (confirmed by G Mitchell) was under a pristine Mudgee Star Party sky in 2000 with my then 31cm. These are the notes:

x186, x156, x131

Mag 11.7 Size 11.5' x 1.4'. Confirmed by G Mitchell. An Extremely !! Faint eg of very very LSB but quite large. In a pretty *ry field as an ill defined streaky, almost non-existent patch of weak gossamer 6' x 1' in PA 110 with a line of *s not superimposed but running beside it mags 10-11. Does not grow to the axis or the core. Very very difficult object.

I have also showed it to Steve Gottlieb (who writes for Astronomy Magazine, formerly of S&T) in 2001 using my 31cm from a pristine site and he confirmed as well.

I have since observed it many times with 46cm where it is a tad brighter but not much bigger or more detailed.

I'm pretty certain Andrew Murrell (Hector) has seen it too (and probably several if not many other advanced Australian observers).

Though it is commonly referred to as a galaxy, it is *not* a galaxy per se. Rather it is a non-rotating coreless shred of stars. A bit like a dismembered limb. There is a 1995 (I think) paper that relied upon a supercomputer simulation regarding this interesting object. If I get a chance in the next day or so, I'll dig it up.

(From my memory of the paper) It seems that one of the possible scenarios that could eventuate from a collision (at a "just right" speed / angle) between Centaurus A* and a fair-sized spiral is a fully supported and rotating girdle of gas, dust and stars around Cen A* plus the core/nucleus of the spiral is ejected plus one or more spiral arms are ejected at high speed.

This simulation actually fits reasonably well with what is observed. ESO 270-17 (a former arm??) is proximate to Centaurus A* (though its re-shift is certainly higher than Centaurus A*)(speeding away from the scene??) while a small peculiar blue compact/elliptical galaxy is also present nearby -- NGC 5237 (the former core/nucleus??).

This is _not fact_ but hypothesis -- but it also explains a lot of peculiar things about these three objects pretty neatly.

BTW, I remember this subject coming up in a discussion between myself another observer (_very_ experienced, but remains nameless) about three years ago in November.

We were having a long, long chin-wag about things seen/hope to see and that person asked about ESO 270-17. I said I'd seen it, and they _flatly_ refused to accept my observation and harrumphed that it was "impossible". The individual was even more surprised when I said I'd seen it (at least twice) in 12". Gary Mitchell was there and confirmed the observation "in person"

"Impossible" -- "don't believe it" -- "can't be seen -- never ever -- not even in 18" they maintained.

Well, as a result, we had a wager (port I think it was) -- that the following year I'd show it to them in my 18" 'scope. April came 'round, so did the person to Mudgee. We dialled it up on the Argo, did the slew and within 10 seconds I had a concession. The transparency on the night was very good, the seeing poor and it was only at 40 degrees elevation.

I also covered it in some detail in a talk I did at the SPSP (2004?? 2005 ???) as part of the Centaurus A*/M83 cluster and I had hoped to cover it in an upcoming Deep Sky Delights article -- probably Feb-March or April next year or the one after.

Have a got at it §AB. It is near/at the limit of detection for 12" under a perfect sky. Let us know how you go.


Best,

Les D
Contributing Editor
AS&T