The Hellenic Navy (HN) (Greek: Πολεμικό Ναυτικό, Polemikó Naftikó, abbreviated ΠΝ) is the naval force of Greece, part of the Greek Armed Forces. The modern Greek navy has its roots in the naval forces of various Aegean Islands, which fought in the Greek War of Independence. During the periods of monarchy (1833–1924 and 1936–1973) it was known as the Royal Navy (Βασιλικόν Ναυτικόν, Vasilikón Naftikón, abbreviated ΒΝ).The total displacement of all the navy's vessels is approximately 150,000 tons.The motto of the Hellenic Navy is "Μέγα το της Θαλάσσης Κράτος" from Thucydides' account of Pericles' oration on the eve of the Peloponnesian War. This has been roughly translated as "Great is the country that controls the sea". The Hellenic Navy's emblem consists of an anchor in front of a crossed Christian cross and trident, with the cross symbolizing Greek Orthodoxy, and the trident symbolizing Poseidon, the god of the sea in Greek mythology. Pericles' words are written across the top of the emblem. "The navy, as it represents a necessary weapon for Greece, should only be created for war and aim to victory."...............The Hellenic Merchant Marine refers to the Merchant Marine of Greece, engaged in commerce and transportation of goods and services universally. It consists of the merchant vessels owned by Greek civilians, flying either the Greek flag or a flag of convenience. Greece is a maritime nation by tradition, as shipping is arguably the oldest form of occupation of the Greeks and a key element of Greek economic activity since the ancient times. Nowadays, Greece has the largest merchant fleet in the world, which is the second largest contributor to the national economy after tourism and forms the backbone of world shipping. The Greek fleet flies a variety of flags, however some Greek shipowners gradually return to Greece following the changes to the legislative framework governing their operations and the improvement of infrastructure.

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This is a bilingual blog in English and / or Greek and you can translate any post to any language by pressing on the appropriate flag....Note that there is provided below a scrolling text with the 30 recent posts...Αυτό είναι ένα δίγλωσσο blog στα Αγγλικά η/και στα Ελληνικά και μπορείτε να μεταφράσετε οποιοδήποτε ποστ σε οποιαδήποτε γλώσσα κάνοντας κλικ στη σχετική σημαία. Σημειωτέον ότι παρακάτω παρέχεται και ένα κινούμενο κείμενο με τα 30 πρόσφατα ποστς....This is a bilingual blog in English and / or Greek and you can translate any post to any language by pressing on the appropriate flag....Note that there is provided below a scrolling text with the 30 recent posts...Αυτό είναι ένα δίγλωσσο blog στα Αγγλικά η/και στα Ελληνικά και μπορείτε να μεταφράσετε οποιοδήποτε ποστ σε οποιαδήποτε γλώσσα κάνοντας κλικ στη σχετική σημαία. Σημειωτέον ότι παρακάτω παρέχεται και ένα κινούμενο κείμενο με τα 30 πρόσφατα ποστς.........

Friday, June 10, 2011

"Milky Way"gives birth to small stars ...[ 2307 ]

Small galaxies may only give birth to small stars

12:45 10 June 2011 by Ken Croswell
For similar stories, visit the Cosmology Topic Guide

Size matters (Image: ESO/Digitised Sky Survey 2)

Size matters (Image: ESO/Digitised Sky Survey 2
It's as if small towns could only produce small people: dwarf galaxies may not be able to produce many large stars.

Our Milky Way, a giant barred spiral galaxy, creates stars both large and small, and astronomers had assumed other galaxies did the same. But a new study of Fornax, a dwarf galaxy orbiting our own, suggests that might not be true.

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Stars of different masses create different chemical elements. Barium tends to form in stars too puny to explode, while very massive stars forge a lot of iron when they detonate.

Fornax has high levels of barium relative to iron, and Takuji Tsujimoto of the National Astronomical Observatory of Japan in Tokyo suggests this is because the galaxy never formed many stars weighing more than 25 suns.

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"It's an intriguing suggestion," says Rosemary Wyse of Johns Hopkins University in Baltimore, Maryland. "I don't think it's definitive. But it points to how useful dwarf galaxies really are in terms of trying to understand how stars form."

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So how could the size of a galaxy determine the size of the stars it gives birth to? Mark Krumholz of the University of California, Santa Cruz, and Christopher McKee of the University of California,

Berkeley, have suggested that the density of a gas cloud might affect the size of stars it can create.

Journal reference: arxiv.org/abs/1105.3218

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