Posts Tagged ‘skywatching’

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Ideal SETI-target planets and K-type stars

April 25, 2013

by tte-77

The Kepler-62 system – home to two habitable zone worlds. The small shining object to the right of Kepler-62f is Kepler-62e. Image credit: NASA Ames/JPL-Caltech.

Its been far too long since I contributed to Sky-Watching on a regular basis. On that sudden note here’s the first post in a while and its exoplanet related.

In the search for extraterrestrial life, NASA’s Kepler team have announced the discovery of Kepler-62 – a multiple planet system composed of five Earth and super-Earth sized planets, two of which are habitable zone worlds, orbiting an orange dwarf or to be precise a K-type main-sequence star.

Ok, so this is cool news right, and a K-type star too.  I’m intrigued.  Has Kepler found ideal SETI-target planets?

K-type stars are of particular interest in the search for other life because they are about three to four times as abundant as sun-like stars, making planet searches easier. K-type stars are also stable on the main sequence for a very long time, around 15 to 30 billion years which is two to three times longer than our own sun  and this may create an opportunity for life to evolve on the terrestrial planets orbiting them.

An artistic view of the system seen from Kepler-62f. Image credit: Danielle Futselaar/SETI Institute

The outermost planet, named Kepler-62f (see image) is about 1.4 times Earth’s radius and has a period of 267 Earth days. If Kepler-62f is a rocky planet with a similar atmosphere to Earth, sitting in the stars habitable zone it could host liquid water on its surface. Kepler-62e, also in the habitable zone is 1.6 times the Earth’s radius with a period of 122 Earth days, it could also host liquid water on its surface.

The authenticity of this multiple planet system was confirmed by a statistical analysis based on previous discoveries of multiple planets by Kepler as the detection of these planets was indirect.  The Kepler astronomers observed gradual loss of the host star’s brightness due to the passage of a planet in the line of sight, and not the planets themselves.  Speaking about the detection process Jason Rowe, Research Scientist at the Carl Sagan Center of the SETI Institute and co-author of the work said “Such calculations are only possible because of the thousands of additional transiting extrasolar planets that Kepler has discovered”.

About the discoveries Jon Jenkins,  Senior Scientist at the Carl Sagan Center of the SETI Institute and co-author of the work said “These discoveries move us farther down the road to discovering planets similar to Earth. While we don’t know if Kepler-62e and f are rocky or whether they have liquid water pooling on their surfaces, their existence shows that the incidence of small worlds in the habitable zone of Sun-like stars is high.

Thus we can look forward to the discovery and detailed characterization of Earth’s cousins in the years and decades to come by future missions and telescopes.”

So there you go – exoplanets, K-type stars, some smart scientists from the SETI Institute, nice images and a post with a final thought…

If Kepler has found ideal SETI-target planets, sort the funding and bring on the future missions and telescopes.

Sources: SETI / spacedaily.com

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April showers of the Lyrid kind

April 17, 2013

by yaska77

Beginning now until the 25th of this month we see the April Lyrid meteor shower (peaking on April 22nd before dawn). The meteors in this shower tend to be bright and leave persistent trails as they enter the Earth’s atmosphere.

In recent years the shower has seen anything from 10 to 20 meteors per hour.

01-wye-downs-perseid-12082012-sky-watching-co-uk

We caught this Perseid meteor flashing across the night sky in August 2012, so we’re hoping to have clear skies for the Lyrids! (click to enlarge) – Credit: Sky-Watching/A.Welbourn

Although that might sound like a fairly mediocre “shower”, it has been known for the Lyrids to surge to over 100 per hour! This is what makes this shower so difficult to predict. How many will we see?

Will it be a downpour of shooting stars or a washout this year!?

Lyrid Meteor Radiant 22.04.2013 01.00UTC Sky-Watching.co.uk

Although the meteors will seem to originate from Lyra, they can appear all over the sky. Shown above at 01:00 UTC (02:00 BST) on 22nd April just at the start of the peak (click to enlarge) – Credit: Sky-Watching/Stellarium

Lyrid meteors originate from a radiant point in the constellation of Lyra which is where this shower gets its name. The best time to look for Lyrid meteors is late in the evening after 21:00 UTC (22:00 BST) however, the waxing gibbous Moon will still be in the sky until the early hours so its light may wash out the fainter meteors.

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Another Perseid from August 2012, this one has more definition to the shape at the end of the streak and is seen heading away from the Andromeda galaxy (click to enlarge) – Credit: Sky-Watching/A.Welbourn

Don’t let this deter you though, the unpredictable nature of the Lyrid shower is what makes it worth watching so we hope you have clear skies!

Now we’ve expressed an interest we’re expecting it to be cloudy, but amateur astronomers are nothing if not optimistic :)

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Regular stargazing and astronomy reports e-petition

December 9, 2011

by tte-77

Sign thr e-petition!

Make astronomy weather reports a regular feature on weather broadcasts

If you follow the popular @sky_watching Twitter feed then you would have noticed the recent re-tweet from @UKAstroPetition about the campaign to make Astronomy Weather Reports a regular feature on UK News. There is an e-petition requesting The Met Office to produce regular stargazing and astronomy related weather information and that it be shown as part of broadcasted weather reports via the BBC.

What is the most frustrating part of being an amateur astronomer? The bloody weather.

Not to be selfish though, not only would success with the e-petition be of great benefit to amateur astronomers, it would also help boost public awareness of the study of the sky and stars, which in turn encourages the study of science for future generations.

Join us and support the e-petition! Visit the official Directgov ‘Regular Stargazing/Astronomy reports’ e-petition here.

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Mercury – hardly ever visible when it is truly dark

September 8, 2011

by tte-77

Mercury profile from Mariner skywatching

Mercury profile from Mariner - Credit: NASA

In his book “The Solar System and Back” (Doubleday, 1970), famed science writer Isaac Asimov (1920-1992) argued that the planet Mercury:

“… is hardly ever visible when it is truly dark. Mercury … will be seen only near the horizon in dawn or twilight, amid haze and sun glare. I suspect, in fact, that many people today (when the horizon is dirtier and the sky much hazier with the glare of artificial light than it was in centuries past) have never seen Mercury.”

Weather permitting 8-15 September amateur astronomers will be presented with an excellent opportunity to view Mercury in the early morning dawn sky. An “inferior planet” because its orbit is nearer to the sun than the Earth’s, Mercury, as Asimov indicated, always appears from our vantage point to be in the same general direction as the sun.

Mercury will be surprisingly easy to see from now through 15 September and will be rising before the sun in the northern hemisphere. Just look low above the eastern horizon during the morning twilight and be sure that it’s about 30 to 45 minutes before sunrise – search for a bright yellowish-orange “star.”

As mentioned in our monthly events guide Mercury was at its greatest elongation just west of the sun, on 3 September. The planet, like Venus, appears to go through phases like the moon.

At its greatest elongation Mercury appeared roughly half-illuminated and the amount of its surface illuminated by the sun has steadily increased as each day passes helping keep it in relatively easy view over the next 7 days.

Mercury and Regulus early September Sky-Watching

Position of Mercury and Regulus early September (click to enlarge) - Credit: Stellarium/Sky-Watching

As a bonus, early on Friday morning, Mercury will have a close conjunction with the bright bluish 1st-magnitude star, Regulus, in the constellation of Leo. Look for them, they will appear to be almost side by side, low near the east-northeast horizon and around 45 minutes before sunrise.

If you intend to view, Mercury will be to the left of Regulus and will shine about 8x brighter than the star. Binoculars may make it easier to sight Regulus – Mercury will then pull rapidly away to the east on successive mornings.

By 15 September it will have substantially brightened, more than any star in the sky with the exception of Sirius. Days later, despite its brightness it will be swallowed up by the dawn glow.

Let’s hope for clear skys over the week ahead!

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ESO Top 100 Images – 50-46

September 7, 2011

by tte-77

Well there’s no mention or images of the new Supernova spotted in a nearby galaxy in this weeks post or indeed any in any relating to this series. Nonetheless we resume the countdown with the (latest) positions 50-46*.

sky-watching Really Hot Stars ESO

# 50 - Really Hot Stars - Credit: ESO

skywatching N44 in the Large Magellanic Cloud

# 49 - N44 in the Large Magellanic Cloud - Credit: ESO

skywacthing Spiral Galaxy NGC 253

# 48 - Spiral Galaxy NGC 253 - Credit: ESO

www.sky-watching.co.uk Artist’s impression of Corot-7b

# 47 - Artist’s impression of Corot-7b - Credit: ESO/L. Calcada

sky watching Trailing stars above Paranal

# 46 - Trailing stars above Paranal - Credit: ESO/Stéphane Guisard (www.eso.org/~sguisard)

To view the previous images from the countdown visit the links below.
55-51 | 60-56 | 65-61 | 70-66 | 75-71 | 80-76 | 85-81 | 90-86 | 95-91 | 100-96

Subscribe via the WordPress tab (side panel) or follow on Twitter for weekly updates to this dedicated series of stunning shots.

* ESO Top 100 Images series positions correct at time of post.

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