2012 : Tahun Yang Ditunggu

Klik sini dan sini 

Aktiviti magnetik semakin aktif di Matahari dan kawasan-kawasan yang hampir denganya. Beberapa letusan solar turut di kesan berlaku dalam skala kecil dengan kekerapan yang agak tinggi.

Permukaan Matahari yang sangat aktif

Letusan solar sedang berlaku di permukaan Matahari 

Keseluruhan permukaan Matahari menjadi semakin tidak stabil. Letusan demi letusan tercetus di permukaannya. Kesudahan fenomena ini adalah ribut magnetik, sebelum Matahari kembali menjadi stabil semula. Ini dijangka berlaku pada tahun 2012

Pic: Solar and Heliospheric Observatory (SOHO) & Global Oscillation at Low Frequency (GOLF) Space Telescope.

Fenomena ribut magnetik yang terjadi setiap lebih kurang 11 tahun memang dinanti-nantikan oleh para peminat dan pemerhati astronomi. Tahun 2012, bakal menyaksikan fenomena ini berlaku sekali lagi. Fenomena ini berlaku apabila berbilion molekul proton dan elektron berlanggar di antara satu sama lain dalam aktiviti magnetik di permukaan Matahari. 

Tahun 2012 merupakan tahun yang agak kontroversi, yang ditunggu-tunggu sekian ramai manusia di planet Bumi ini terutama sekali para saintis-saintis angkasa lepas kerana, pada tahun itu jugalah nanti akan berlakunya fenomena "Planetory Reunion". Fenomena yang berlaku sekali dalam beberapa ribu tahun ini bakal menyaksikan kesemua planet-planet dalam Bima Sakti akan berada dalam kedudukan selari mengadap Matahari, dan dalam masa yang sama, satu lagi fenomena agung dalam cabang ilmu sains astronomi akan berlaku, iaitu Galaksi Bima Sakti akan melengkapkan pusingannya mengelilingi pusat cakerawala.

Jadi apa kesimpulan anda mengenai 2012?

The Often Neglected Star - Our Sun

An introduction....

Astronomers spend their lives looking at the stars, but all too aften the nearest star is neglected, the Sun.

The Sun is the very heart of the Solar System. Its light and heat enables life to exist on our planet. The Sun itself is physically enormous, spanning some 1.39 million kilometres in diameter (over 100 times greater than the Earth). Nevertheless, compared to other stars in our galaxy the Sun is relatively small and unremarkable. It lies on average 149.6 million kilometres from Earth and spans about 0.5 degrees in angular diameter as seen from our planet. As the Sun is gaseous its rotation period varies with latitude, with the equitorial region moving faster than at the poles. The average rotation period is 27.25 days.

The Sun shows a well defined cycle of activity that is referred to as the solar cycle. It was a German farther and son team of David and Johannes Fabricius who first published observations of sunspots in June 1611, a year before Galileo's similar observations.

Continuos support records exist from 1849 onward, around the time that the pattern of the solar cycle was first noticed. The cycle is defines by the amount of active regions visible on the disc, the number of which wax and wane in a regular pattern over approximately an 11-year period. For a typical cycle, smaller spots appear at higher latitudes and, as activity increases, the spot activity migrates toward the equator and during the maximum activity of the cycle they generally concerntrate around 15 degrees north and south of the solar equator.

Magnetism is the key to all this solar activity. Active regions of spots, huge and intricate prominences, loops and streamers at the chromosphere and coronal mass ejections are all shaped and driven magnetically. The solar cycle itself results from the recycling of magnetic fields from the movement of the material in the interior of the sun.