Concentric Circles

Southerly Star Trails

I began this image with a single 25 seconds exposure, changed the exposure, then exposed a further 99 exposures at 15 seconds. Hence: bright stars, followed by a short gap then slightly dimmer trailings.

Why? It seemed like a good idea at the time, because I wanted to ensure my Japanese Maple tree was illuminated in the corner of the first frame. Perhaps I shone a torch, I can’t remember, because it was not long enough ago.

The observant reader will deduce from this timing sequence that the stars were rotating clockwise. We do things properly here in the Southern Hemisphere.

You may also notice no obvious pole star. That’s because we don’t have one. Or at least we don’t have a bright one. And it’s not near the pole.

This is all in the southernmost constellation of Octans.

Image: Wikimedia Commons

I doubt if there is any other constellation in the sky which is more devoid of bright stars than Octans is. Which used to make it extremely difficult for us southerners to polar align our telescope mounts. Now we have laptop software which does it for us. Easy-peasy.

Polaris Australis (Sigma Octantis) is the brightest star in the central vicinity at an unimpressive +5.44 magnitude (barely visible).

Sigma is the closest bright streak in the 3 o’clock direction, beyond the little triangle of stars at the centre of my image. It is located about 68 arc minutes from the South Celestial Pole, which is of course at the centre of all those arcs.

The above feature image was from the last clear sky here, twenty-five days ago on 6th December. I’m not happy about losing all those evenings under the stars – but this time last year we had already endured many more days and nights of intense bush-fire smoke.

As my Bride wisely asked me, “Which of those two scenarios would I prefer?”

πŸ₯΄


Happy New Year

Image attribution: Wikimedia Commons – Nevit Dilmen

Very best wishes to all of my readers.

Thanks very much for your visits and comments during 2020.

Let’s hope that in 2021 we can regain our freedom and that our political leaders will show a little more compassion and stop telling lies.

Camera:Canon 60D, 50 mm, f/5.6, ISO 250.
Exposure:1 x 25 sec + 99 x 15 sec = 25.25 minutes.
Field of View:Approximately 40Β° x 27Β°.
Software: DPP, Star Stax v0.70, GIMP.
Observatory location:34Β° South.
Image date:2020-12-07.

Images Β© Roger Powell

I’m a founder member of Macarthur Astronomical Society

21 Comments

      1. Still here, you say? Well that’s disappointing. I was assured all ills and problems would magically vanish. It seems I was dreaming.

        I am hoping for clear skies to be over your head soon. You deserve them. Happy New Year.

        Liked by 2 people

        1. Thanks, Jim.

          The clock struck midnight and the problems didn’t go away but I hope the pessimism can be replaced by some degree of optimism about the year ahead.

          Reality check: covid is most likely going to be our constant companion. A bit like clouds.

          Liked by 1 person

      2. Yeah kinda expected that. We have 6hr 30min left of 2020, and expect we’ll be struggling a few more months. But the change in administration will certainly be an asset. M πŸ™‚

        Liked by 1 person

        1. I hope Biden can bring your country together again – but as an outside observer, the divisions seem to be deeper than ever. I’m daydreaming again but Trump should be charged with genocide by neglect.

          Liked by 2 people

          1. Nah . . . people forget the division really grew when Democrats took the Obama victory as a “mandate” and started playing hardball. Under Harry Reid, rules were changed to bypass Republican objections (rules that Mitch was happy to use when Republicans gained control of the senate).

            The point being, every new administration comes into power not with the idea of reconciling with the other side, but to punish them and their followers. it’s a vicious circle the Democrats are happy to continue . . . as will the Republicans when, inevitably and because people in power act like jerks, they will regain control.

            I’m sure you’ve already heard Democrats say they have a mandate . . . despite the votes having gone pretty much 50-50. Look for the Biden administration to piss off a lot of people on the other side, as did the Trump administration, and the Obama administration, and the Bush administration, and so on and on and on.

            We need fresh blood and new ideas, but the parties are anything but. No honesty, no honor, no compassion, no conscience . . . that’s the current mottoes of the two major political parties in the US.

            Liked by 1 person

            1. “Mandate” is a word often bandied around here in Oz by the winning parties. The word has no meaning, no definition – not even a mention – in our constitution or electoral laws. But still they use it, to try to force legislation through a hostile Senate.

              The Senators of course, all claim they have their own “mandates”…..and so it goes on. But those on the cross-benches are often willing to relinquish their “mandate” claims if suitably bribed with concessions or financial grants to their electorates. That then goes on their CVs like a badge of “honour”.

              The only thing any of them understand is the difference between 49.9% and 50.1%.

              I hope things improve for the US, I really do.

              Liked by 2 people

  1. Happy New Year, Thanks for all your marvelous photos including the Japanese maple. In my world, a maple tree is a maple tree wherever it is. Your Bride is a wise woman who asks the right questions. With gratitude, Fran

    Liked by 2 people

    1. She doesn’t usually ask questions. More likely she’s issuing directions. My job is to lift heavy stuff and try not to get in the way. πŸ˜‚

      Thanks for your always generous contributions here, Fran. Best wishes.

      Roger

      Like

  2. Thank you, Ggreybeard, and while I thank you for your wishes and offer mine in return, I don’t hold out much hope for our political ‘leaders’ to suddenly become unlike politicians throughout history and stop lying, let alone be more compassionate.

    Neat picture . . . sorry about the cloudy skies, but, yeah . . . no smoke.

    Liked by 2 people

    1. I share much of your cynicism – my new year’s wish was grounded more in blind daydreaming than in stark reality.

      But there can be some political leaders whose compassion and integrity stand out. New Zealand’s Jacinda Ardern comes to mind. But then, I don’t live or vote in New Zealand.

      Liked by 3 people

    1. Hi Dave, it’s a dead region, so PA to the SCP has been a real problem in our hemisphere – but the plate solving PA feature of SharpCap (which I use) and probably other imaging software has made it so easy.

      Like

Your say.......

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s