The mistakes that slipped through in the April MNASSA is an unfortunate reflection of the rocky path that this issue took from conception to publication. The same problems explain why it was slightly late. The biggest contributing factor was perhaps the fact that I fell in an area that experienced load shedding by the electricity supply network on three nights a week from 20h00 to 22h30, the time I normally spend editing MNASSA. I want to apologise for this.
Near-infrared observations taken at Gemini North have detected ammonia in the spectra of the coolest brown dwarf ever discovered. This is the first time such a finding has been made in near-infrared spectra of a sub-stellar object other than a planet.
The fifth and final servicing mission of HST (Hubble Space Telescope), originally scheduled for late August, is unlikely to happen before late September or early October. The delay is not due to the telescope or the Shuttle but the time needed to prepare a second external fuel tank - that familiar dark brown tank on which the Shuttle gets launched.
In a previous discussion about the use of powerful green lasers in astronomy (MNASSA65, 5&6, June 2006, 80), the importance of the responsible use of these potentially dangerous devices was repeatedly stressed. In particular, one should not shine them at airplanes since a case in America resulted in strict regulations being introduced. After a recent spate of incidents in Australia, a total ban on powerful green laser pointers has just been introduced.
On the 30th of June 1908, exactly 100 years ago this month, a large airblast occurred in the Siberian taiga, near the Podkamennaya Tunguska River. It has become widely known as the "Tunguska Event". Environmental effects of the explosion were observed in almost the whole northern hemisphere and many traces of the impact are still well preserved in the epicentre area. In spite of all the efforts of several generations of scientists from different disciplines and from many countries, there are still some unanswered questions.
Exoplanets are literally being discovered by the dozen now with the "transit" method gaining speed by the moment. One transit-search project in particular, namely Super-WASP ("Wide Angle Search for Planets") has really taking off. Ten confirmed extra-solar planet discoveries in six months.
Sir Arthur C. Clarke, CBE, died at his home in Sri Lanka on 18 March, aged 90 years. Hilton Ratcliff and Keith Gottschalk both wrote articles for their respective Centre newsletters. The following notes have been compiled from their contributions:
Astronomers looking at galaxies in the Universe's distant past received a similar perplexing announcement when they found nine young, compact galaxies, each weighing in at 200 billion times the mass of the Sun. The galaxies, each only 5 000 light-years across, are a fraction of the size of today's grownup galaxies but contain approximately the same number of stars. Each galaxy could fit inside the central hub of our Milky Way Galaxy.
Omega Centauri has been known as an unusual globular cluster for a long time. A new result obtained by the NASA / ESA Hubble Space Telescope and the Gemini Observatory reveals that the explanation behind Omega Centauri's peculiarities may be a black hole hidden in its centre. One implication of the discovery is that it is very likely that Omega Centauri is not a globular cluster at all, but a dwarf galaxy stripped of its outer stars, as some scientists have suspected for a few years.
An unusual event was held at the Muizenberg Pavilion on 11 May, under the auspices of the African Institute for Mathematical Sciences. Tickets were available to the general public but were sold out almost immediately, before most people knew about it. Using all their charm and influence, some local astronomers nevertheless managed to gain admittance.
The Hoba Meteorite is, by any standards, a most extraordinary object. The largest known single meteorite in the world, it is situated in northern Namibia on the farm Hoba West. Located at 19° 35.5' S, 17° 56.0' E, it lies some 20km west of Grootfontein and 65km south east of the noted mining town of Tsumeb. Amazingly rectangular in shape, with sides c. 3m x 3m x 1m, it has been calculated to weigh some 61 000kg and is estimated to have landed less than 80 000 years ago (McCorkell et al, 1968). It is classified as a Group IVB meteorite, a small group of only 13 Ni-Fe meteorites which has recently been shown to be 4 527 ± 29 million years old (Smoliar, 1996).
Over the past few months we tended to dwell more on constellations containing faint objects. Well, this Deep-Sky Delight promises to be a bright-object Delight! The constellations Centaurus and Orion are the only two constellations that boast two 1st magnitude stars.
Newspaper and magazine reporters can get their story quite badly muddled up when trying to report on facts that overwhelm their intellect. When it comes to astronomy, it can be particularly bad at times.