How low can you get?

[Dr Paul Leyland]

Jeremy’s recent update on the HR Lyr campaign prompted me to explore the VSS pages in greater detail.  Over there is a link to a fascinating article on the observation from the UK of variables with a declination more than 30 degrees south of the equator.  This got me thinking …

My observatory is at a latitude of 28.64 degrees north so, in principle, I could reach a declination of 90 – 28.64 – 0.5 = 61.9 degrees south, where the 0.5 allows for atmospheric refraction.  In practice, I don’t have a perfectly flat ocean horizon to the south.  Far from it: it’s very lumpy indeed.  However, omega Centauri, at 47.5 degrees south has been imaged successfully from here.

I’ll see what I can do.  Anything below -50 will be nice and, who knows, -55 might be possible.

Of course, other observers are encouraged to join in the fun, and should choose targets appropriate to their latitude.  I remember seeing a photo of the Big Dipper taken from northern Queensland where a couple of the stars were only two or three degrees above the horizon.

P.S.  The classical risque answer to the question posed in the subject is “Chihuahuas”. 😉

[Robin Leadbeater]

For those of us further north it can sometimes be more interesting looking in the other direction 😉

[Dr Paul Leyland]

Indeed, this is a worthy addition to the terms of the challenge.

[Peter Anderson]

In fact the big dipper can be seen from Southern Queensland if you time it right. My images on this BAA site show how it was done from Noosa Heads (26 deg S), early evening, in early May 1968. The whole story is told.

From Northern Queensland, add another 10 degrees of altitude… Very easy.

[Dr Paul Leyland]

Thanks for the clarification.  I’d mis-remembered the details.

[Dr Paul Leyland]

I can now give some limitations for my site.  The fork mount on the main scope won’t allow pointing south of -47.5 degrees.  In the other direction, the limitation is about +77 degrees, which means I can’t observe some of the BAA-VSS program.

The on-site images of ω Centauri were taken by Kevin Hills some years back.  His observatory is a few metres away from mine and his GEM is nowhere near as fussy.  It will quite happily point his OTA very close to the nadir, as we discovered some weeks back.

Perhaps I should take a tripod, DSLR and telephoto lens down to Fuencaliente for an uninterrupted southern horizon where -60 declination should be a real possibility.  A nice target at this time of the year might be ε Indi which culminates at about 5 degrees altitude.

[Nick James]

The furthest south declination object I’ve imaged from La Palma is at around -62.2 deg south (see attached). That was about 2000m altitude looking straight down the Caldera de Taburiente.

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