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Wednesday, 22 February 2012

SPA ENB No. 326

                The SOCIETY for POPULAR ASTRONOMY
         Electronic News Bulletin No. 326  2012 February 21

Here is the latest round-up of news from the Society for Popular
Astronomy.  The SPA is Britain's liveliest astronomical society, with
members all over the world.  We accept subscription payments online
at our secure site and can take credit and debit cards. You can join
or renew via a secure server or just see how much we have to offer by

SPA Planetary Section - Announcement

I wish to inform you that as of now I have stood down as the Planetary
Section Director for the SPA. Fellow member and Planetary Imager Alan
Clitherow has taken over from me although I will stay on as his assistant
for a while to ease him into the role.

I have carried out the role for a little over two years and it was a
privilege and honour to be asked to do it. My reason for standing down is
that although I still enjoy observing the planets it is not my main passion
in Astronomy anymore. I have an 18" and 24" Dobsonian and enjoy going deep to the point that when I'm fully dark adapted (my skies approach mag 6 on a good night) I don't want to look at Jupiter or Mars as it affects my dark adaption! I tend to only observe the planets now in twilight or when there's a moon in the way of faint fuzzies. I do make an exception for a special event happening though or a night of exceptional seeing - the thrill of a visual view of Mars, Jupiter or Saturn under exceptional seeing never goes away! I really appreciate all the contributions I've received over the last
two years and hope I've fully answered any queries.

Alan is very keen to take on the role and an accomplished imager. I hope you give him the support you gave me. I will obviously remain an SPA member as I think it's one of the best amateur organisations going and you will still hear from me as an assistant/member.

All the Best,

Andrew Robertson
Assistant Planetary Section Director


Many television channels offer a "+1" option so that if you miss your favourite show you can watch it an hour later.  But what if you miss a stellar outburst? That's no problem in the case of Eta Carinae, as 170 years after the "Great Eruption" a delayed broadcast has come though much to the delight of astronomers.

Eta Carinae is a bright double star that exhibits periodic outbursts, and it belongs to a class of stars known as Luminous Blue Variables. The Great Eruption was one such outburst, and it was visible from Earth between 1837 and 1858. This resulted in Eta Carinae becoming the second brightest star in the sky and losing 20 solar masses worth of material during the two decades.

Some of the light that was emitted at the time of the eruption travelled away from Earth, but then bounced off a dust cloud. This "light echo" then sent the signal back to Earth allowing astronomers to gather valuable information. However, this new data is raising more questions than answers as it turns out that outflow from Eta Carinae is much cooler than other similar stars.  This means that computer models of Luminous Blue Variable will most likely have to be changed to include this observation.

University of Hawaii

A team of astronomers have discovered a potentially habitable Super-Earth orbiting a star only 22 light years away.  It is the second planet to be discovered around GJ 667C and it has an orbital period of nearly 29 days. While this is still very short, the planet actually receives almost the same amount of energy from its star as the Earth does from the Sun. This is because the infrared light from the star is absorbed as heat. Thus surface temperatures could be similar to those on Earth.

A Super-Earth is a planet that is between two and ten times the mass of the Earth, and this one is believed to be a minimum of 4.5 Earth masses. The planet orbits an M dwarf star, which is a star smaller than our Sun, which is depleted in metals (astronomers refer to anything other than hydrogen and helium as metals). It is thought that stars that lack enough metals wouldn't have had enough material in the circumstellar disc to form planets early in the stars lifetime, which makes this discovery unusual.


The Interstellar Boundary Explorer has discovered that material beyond our Solar System differs from that inside. Our Solar System is separated from the rest of the Universe by an invisible boundary known as the heliopause. This boundary is created by the solar wind interacting with the interstellar medium. IBEX can detect particles coming from beyond the heliopause, and it has found that the ratio of oxygen to neon is higher within the Solar System than beyond it. This extra oxygen in the Solar System could mean that our planetary neighbourhood was born in a more oxygen rich region of the Galaxy or that there is oxygen trapped within dust grains in interstellar space.  IBEX has also measured the flow of hydrogen, oxygen, and neon from outside our Solar System for the first time.

By Richard Bailey, SPA Solar Section Director
Rotation Nos. 2118, 2119


   A good level of AR activity during the month of varying patterns and numbers of individual sunspots.  Faculae were seen daily.  The NH had most activity, and it was noticeable that some AR's there were sited only a few degrees above the equator.  MDF totals for the whole year 2011 showed a sudden surge of AR activity, almost doubled, from the end of August onwards.

Week 1.   On the 2nd. SH AR 1388 was by the CM, 1386 nearing the W limb ahead of it, and 1389 following with 13 spots and a good leader. NHAR1390 with seven small spots was lonely in the NH near the CM .  On the 7th the NH had 4 AR's spread across the disk, 1391 – 94,  the SH 88 and 89 by the W limb.

Week 2.   5 NH AR's across the disk on the 10th.,1391 the strongest with 15 spots just past the CM, It was by the W limb on the13th, less active.  SH empty.

Week 3.   A surge of AR's  across the disk, with 9 on the 15th., 6 NH, 3 SH. NH AR1396 most active with 15 spots.  SH AR1397 half way to the CM. 1399 just behind, 1400 ahead.  Round the E limb had come the month's largest pair of
AR's NH1401 and just above NH1402They dominated the disk as they went westwards and developed split headers.  The leader of 1402 was a (protected ) naked eye spot on the 19th.

Week 4 to end of the month.   On the 22nd. NH AR' 1408 just round from the E limb to make 6 NH AR's  across the disk. NH1401 and 02 still good clusters. SH blank.  NH AR1410 by the E limb with a large leader, showing the Wilson Effect well. SH AR1411 appeared by the CM on the  29th. a small single spot. The month ended with 3 NH AR's,  AR1413 was the largest with 11spots and near the CM, 1418 above.  3 SH AR's  nearing the W limb.

MDF     5.16      R  72.97


Some excellent prominences were on  show during the month, amongst daily smaller ones, and filaments were regularly seen especially across the NH where most AR activity took place.   No flares were seen, but small amounts of plaging were seen to AR's.  NH AR 1393 had small areas of  very bright plaging around  1120UT on the 5th.

MDF   4.28

Visit the Solar link from the SPA Homepage, go to Reports and select the month for which you want to see samples of the fine pictures and drawings sent in by Solar Section members.

Bulletin compiled by Amanda Doyle



Good Clear Skies
Colin James Watling
Various Voluntary work-Litter Picking for Parish Council (Daytime) and also a friend of Kessingland Beach (Watchman)
Real Astronomer and head of the Comet section for LYRA (Lowestoft and Great Yarmouth Regional Astronomers) also head of K.A.G (Kessingland Astronomy Group) and Navigator (Astrogator) of the Stars (Fieldwork)
Information -- More Info -- And More Info

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