Galaxies (natural sciences)

-
astronomers classify galaxies into three major categories, but here i'm gonna discuss 'bout Spiral Galaxies first okay :D

Spiral Galaxies
Like the Milky Way, other spiral galaxies also have a thin disk extending outward from a central bulge. The bulge itself merges smoothly into a halo that can extend to a radius of over 100,000 light-years. Together, the bulge and halo of a spiral galaxy make up its spheroidal component, so named because of its rounded shape. Although no clear boundary divides the pieces of the spheroidal component, astronomers usually consider stars within 10,000 light-years of the center to be members of the bulge and those outside this radius to be members of the bulge and those inside this radius to be members of the halo.

The disk component of a spiral galaxy slices directly through the halo and the bulge. The disk of a large spiral galaxy like the Milky Way can extend 50,000 light-years or more from the center.The disks of all spiral galaxies contain an interstellar medium of gas and dust, but the amounts and proportions of the interstellar medium of gas and dust, but the amounts and proportions of the interstellar medium in molecular, atomic, and ionized forms differ from one spiral galaxy to the next. Spiral galaxies with large bulges generally have less interstellar gas and dust than those with small bulges.

Not all galaxies have disks but do not appear to have spiral arms. These are called lenticular galaxies because they look lens-shaped when seen edge-on (lenticular means "lens shaped"). Although they look like spiral galaxies without arms, lenticular galaxies might more appropriately be considered an intermediate class between spirals and ellipticals because they tend to have less cool gas than normal spirals, but more than ellipticals.

 Among large galaxies in the universe, most (75% to 85%) are spiral or lenticular. (Spiral and lenticular galaxies are much rarer among small galaxies.)
sumber : buku praktice for exercise TOEFL page 166


Komentar

Posting Komentar

Postingan populer dari blog ini

kamus cowok !

-
Nah ini bahasa cowok yang cewek mesti tau! BAHASA COWOK: ku telepon nanti artinya: suatu saat di abad depan. BAHASA COWOK: Aku perlu ruang artinya: untuk cewek2nya yang Lain. BAHASA COWOK: Gak ah, ntar aku dimarahin cowok kamu lagi artinya: Uda punya cowok belom? BAHASA COWOK: kita lihat saja akan kemana hubungan ini artinya: sang cewek harus mundur dan sang cewek membuat sang cowok merasa terpaksa. BAHASA COWOK: Hai, temanmu manis ya? artinya: sang cowok menyukai temanmu dan sang cowok menggunakanmu untuk mendekatinya. BAHASA COWOK: Jangan berlebihan artinya: sang cowok tidak punya perasaan yang sama terhadapmu. BAHASA COWOK: Aku tidak siap membangun hubungan ini artinya: sang cowok tidak ingin menjalin hubungan denganmu. BAHASA COWOK: Kita masih bisa berteman artinya: ini sudah berakhir dan mungkin terakhir kalinya sang cewek bakaL melihat sang cowok. BAHASA COWOK: apa sih yang ngga utk kamu? ada dua kemungkinan: dia bener2 suka sama kamu atau dia playboy sejati BAHASA COWO...
Baca selengkapnya

Jejak Panjang Seni Lukis Modern Indonesia part.2

-
Gambar
TENTANG AFFANDI Affandi sendiri adalah kelahiran Cirebon pada 1907. Dia putra dari R. Koesoema, seorang mantri ukur di pabrik gula di Ciledug, Cirebon. Pendidikan formalnya cukup tinggi, mulai dari HIS, MULO hingga AMS di jaman Belanda. Namun, bakat seni lukisnya yang sangat kental mengalahkan disiplin ilmu lain dalam kehidupannya, dan memang menjadikan namanya tenar sama dengan tokoh bidang lainnya. Pada umur 26 tahun, pada 1933, Affandi menikah dengan Maryati, gadis kelahiran Bogor. Affandi dan Maryati dikaruniai seorang putri yang nantinya akan mewarisi bakat ayahnya sebagai pelukis, yaitu Kartika Affandi. Sebelum mulai melukis, Affandi pernah menjadi guru dan pernah juga bekerja sebagai tukang sobek karcis dan pembuat gambar reklame bioskop di salah satu gedung bioskop di Bandung. Pekerjaan ini tidak lama digeluti karena Affandi lebih tertarik pada bidang seni lukis. Sekitar tahun 30-an, Affandi bergabung dalam kelompok Lima Bandung, yaitu kelompok lima pelukis Bandung bersam...
Baca selengkapnya

Mickey Mouse

-
Gambar
Mickey Mouse is a cartoon character created in 1928 by Walt Disney and Ub Iwerks at The Walt Disney Studio.[3] Mickey is an anthropomorphic mouse and typically wears red shorts, large yellow shoes, and white gloves. He is one of the most recognizable cartoon characters in the world and is the mascot of The Walt Disney Company, the world's largest media conglomerate in terms of annual revenue. Mickey debuted in November 1928 in the animated cartoon Steamboat Willie after initially appearing in a test screening earlier that year. He went on to appear in over 130 films including The Band Concert (1935), Brave Little Tailor (1938), and Fantasia (1940). Mickey appeared primarily in short films, but also in a few feature-length films. Nine of Mickey's cartoons were nominated for the Academy Award for Best Animated Short Film, one of which, Lend a Paw, won the award in 1942. In 1978, Mickey became the first cartoon character to have a star on the Hollywood Walk of Fame. Beginning ...
Baca selengkapnya