Category: Astronomy

Why do stars twinkle? It’s a similar effect to why a hot road looks shimmery. The turbulent atmosphere refracts the incoming starlight to different degrees so the “beam” of light reaching your eye becomes randomly distorted but deviates only minutely from its path, just enough so that it looks like the star is twinkling. It’s the bane of ground-based astronomers and is part of the reason we sent up the Hubble space telescope. However, there are techniques that can overcome twinkle.

Twinkle no more Little Star

A laser optics system can produce a guide star anywhere in the night sky of the southern hemisphere, thanks to work by scientists at Cerro Paranal in Chile, home of the ESO Very Large Telescope array. The star allows astronomers to apply adaptive optics systems to their telescopes effectively cancelling out atmospheric disturbances, better known as a star’s twinkle!

Read the latest on detwinkling in the Spotlight Newsletter

New measurements published earlier this month support recent claims that the planetary membership of our Solar System should be extended to include a tenth that is bigger than Pluto. 2003 UB₃₁₃ was first spotted in January 2005 by Mike Brown’s team at Caltech, but recent thermal emission measurements have recently allowed German scientists to estimate its diameter at approximately 3100 km, some 700 km larger than Pluto. This makes it the biggest object to be discovered in the solar system since the discovery of Neptune in 1846. For comparison, Earth’s Moon has a diameter of about 3500 km.

Get the new spin in my : Spotlight Science News column on PSIgate.

Rather a coincidence that Hubble images of the so-called tenth planet “2003 UB313” claiming that it’s probably not Pluto’s big brother at all but more like a slightly bigger twin, should be released the day before new results from German astronomers appear that show UB313 to be some 700 km wider!

Of course, the reporter covering the HST results will have known in advance (embargoed press release and all that) about the German results, but obviously wanted to scoop the story with another related item.

My sources tell me, however, that there are no authorized results from the HST measurement, as these will take another month to complete.

Watch out for my full report on the published, peer-reviewed work on UB313 in PSIgate Spotlight coming soon…

The BBC reports that the US Stardust probe has returned to earth after its 3billion mile round trip to the comet Wild 2. It returns with a payload of dust trapped in an aerogel. The pristine dust from the very early solar system should tell scientists a great deal about the evolution of our planetary neighbourhood. Watch this space.

Oh, one thing (that should really be reserved for my Sig Fig blog) BBC reporter Helen Briggs refers to the probe’s speed – 46,660kph (29,000mph) and it’s altitude when its parachute was deployed – 32km (or 105,000 feet)

I’ll leave regular SigFig readers to draw their own conclusions about how I would normally comment on such units!

According to a Cambridge U press release just in, the longest ever X-ray observation (1 million seconds) of a galaxy cluster proves that black holes can span intergalactic distances and actually block growth of the largest galaxies.

The Cambridge team has obtained new evidence that black holes are far more powerful cosmic entities than previously thought. Their influence can span vast distances, the researchers claim, heating the gas between galaxies and putting a restraining order on galactic size as stars can only form when gases cool. “It’s as if a heat source the size of a fingernail heats up a region the size of Earth,” team member Andrew Fabian explained.

Don’t you just love these comparisons? Why not say a gas fire heating up Jupiter instead, or an LED heating up the moon, or something equally unimaginable…oh well…the research replete with simile I assume is published in the December “Monthly Notices of the Royal Astronomical Society”. It’s like a single research paper illuminating a pan-galactic civilisation, or not as the case may be.

SciScoop member “barakn” commented on a recent posting about the massive black hole that astronomers claim to have found. As ever, there are two sides to a story and, as barakn points out, conflicting research has now been published that suggests it would have taken three galaxies colliding to eject such a large black hole, so it is perhaps more likely that what at first looked like such an astronomical object is in fact a common or garden quasar…

Isn’t it about time astronomers abandoned the word “planet”? It’s become almost meaningless in the light of recent discoveries.

Pluto has been relegated to “small planet-like thing” while objects beyond the classical solar system turn out to be more planety than some of the actual planets, and most recently a moon, is now being touted as a planet. Add those really big asteroids and planetisimals to the equation and it makes you wonder whether our lexicographical feet will ever feel terra firma again.

Images reveal Titan’s secrets: “Spacecraft is 8.9 feet in diameter and 703 pounds (317 kg).”

Those significant figures fascinate me! Why do news agencies insist on giving us such levels of alleged precision. 8.9 feet! That’s 106.8 inches as opposed to 108 inches. Who cares about that 1.2 when you’ve travelled 2 billion miles from home? And, where did they get that 703 pounds, 317kg? Presumably, thes figures have been converted back and forth as I reckon the craft was more than likely given as 700 pounds and someone turned that into kg somewhere and then turned it back again using different conversion factors…but, who cares. 700 lbs, 300 kg, it’s not like anyone is going back to Titan to check.

I just got a software planetarium to review…very nice program allows you to put in your city or coordinates and then shows you the night sky as it would appear if there were no clouds. There’s the water carrier (Aquarius), the archer, and the various planets.

All seems in order, there are a few constellations I wasn’t familiar with – the hare (turns out to be lepus), the air pump (that’s Antlia) and “poop”. Poop? Nice! I did a quick search on some French astronomy websites and came up with the answer, Poop is what the French call Puppis. This one was originally part of the larger constellation Argo Navis. Indeed, it was the stern, or poop deck of the mythological ship, the Argo.

So, not only am I ignorant of the constellations, I don’t know my classics well enough either. But, thankfully the poop isn’t the last turd in constellations.