its about stars

1. ORIGIN OF STARS
IMAGINE YOURSELF IN A VIDEO GAME ZOOMING BACK
THROUGH SPACE AND TIME AT WARP SPEED. ALONG THE
WAY YOU ARE PULLED BY GRAVITY, BUFFETED BY
TURBULENT GASES AND MAGNETIC WAVES, AND
EXPOSED TO INTENSE RADIATION. AT 350,000 YEARS,
YOU WITNESS THE BIRTH OF EARLY STARS, AND THEN
WARP BACK TO THE PRESENT TO TELL SCIENTISTS WHAT
YOU OBSERVED. YOU'RE ON THE PATH TO SOLVING ONE
OF THE MOST PERPLEXING CHALLENGES FOR
SCIENTISTS TODAY—THE PHYSICAL PROCESSES THAT
FORM STARS AND STAR CLUSTERS IN THE MILKY WAY
AND BEYOND.

2. THAT'S THE SCENE ASTROPHYSICISTS AT THE
UNIVERSITY OF CALIFORNIA, BERKELEY AND
LAWRENCE LIVERMORE LABORATORY (LLNL) ARE
CREATING THROUGH FIRST-OF-A KIND SIMULATIONS
RUN ON THE PLEIADES SUPERCOMPUTER AT THE NASA
ADVANCED SUPERCOMPUTING (NAS) FACILITY AT AMES
RESEARCH CENTER. COUPLING REAL OBSERVATIONS
FROM THE HUBBLE SPACE TELESCOPE AND OTHER
SPACE-BASED OBSERVATORIES WITH THEIR STATE-OF-
THE ART 3D CODE, ORION2, THESE SCIENTISTS ARE
HELPING EXPERTS AROUND THE GLOBE PIECE
TOGETHER THE ORIGIN OF STARS, STELLAR
CLUSTERS, AND THE HIGH-MASS STARS THAT FORM
WITHIN THE CLUSTERS.

3. •STARS ARE HUGE CELESTIAL BODIES MADE MOSTLY OF
HYDROGEN AND HELIUM THAT PRODUCE LIGHT AND HEAT FROM
THE CHURNING NUCLEAR FORGES INSIDE THEIR CORES.
•ASIDE FROM OUR SUN, STARS APPEAR AS DOTS OF LIGHT IN THE
SKY. EACH AND EVERY ONE OF THEM IS LIGHT-YEARS AWAY FROM
US AND MUCH BRIGHTER THAN OUR OWN STAR, THE SUN.
•STARS ARE THE BUILDING BLOCKS OF GALAXIES AND IN A SENSE
LIFE AS WE KNOW IT.
•OUR GALAXY THE MILKY WAY CONTAINS AN ESTIMATED 300
BILLION STARS ALONE.
•OBSERVATIONS CONCLUDED THAT STARS WITH HIGH MASS
USUALLY HAVE SHORTER LIFE SPANS. THEY NONETHELESS LAST
FOR BILLIONS OF YEARS IN GENERAL.
•STARS ARE USUALLY BIRTHED IN HYDROGEN-BASED DUST
CLOUDS CALLED NEBULAE.
•STARS ARE CLASSIFIED BY THEIR SPECTRA AND THEIR
TEMPERATURE. THERE ARE SEVEN MAIN TYPES OF STARS. IN
ORDER OF DECREASING TEMPERATURE, O, B, A, F, G, K, AND M.
THIS IS KNOWN AS THE MORGAN–KEENAN (MK) SYSTEM.

4. •THE MAJORITY OF ALL STARS IN OUR GALAXY AND EVEN THE UNIVERSE
ARE MAIN-SEQUENCE STARS. OUR SUN IS A MAIN-SEQUENCE STAR, AND
SO ARE OUR NEAREST NEIGHBORS, SIRIUS AND ALPHA CENTAURI A.
•THE MAJORITY OF STARS, AT LEAST UNTIL NOW OBSERVED, ARE
TYPICALLY RED DWARF STARS.
•MANY STARS COME IN PAIRS. THEY ARE BINARY STARS THAT ORBIT A
COMMON BARYCENTER.
•STARS HAVE LIFE CYCLES BASED ON THEIR INITIAL MASS.
•STARS DO NOT TWINKLE. THIS IS USUALLY CAUSED BY EARTH’S
TURBULENT ATMOSPHERE INSTEAD.
•AS FAR AS THE HUMAN EYE CAN TELL, THERE ARE NO GREEN STARS. AT
LEAST, WE CAN’T PERCEIVE THEM.
•WITH THE NAKED EYE, WE CAN PERCEIVE AROUND 2.000 – 2.500 STARS.

5. AS LONG AS MAN COULD GAZE INTO THE NIGHT SKY, STARS HAVE
BEEN OBSERVED, DATED, AND ANALYZED. ONE OF THE OLDEST STAR
CHARTS AND SURPRISINGLY ACCURATE CHARTS APPEARED IN
ANCIENT EGYPTIAN ASTRONOMY IN 1534 BC. EVEN SUPERNOVAS
WERE RECORDED SINCE ANCIENT TIMES, FOR EXAMPLE IN 185 AD,
CHINESE ASTRONOMERS RECORDED A SUPERNOVA THAT IS NOW
CLASSIFIED AS SN 185.
STARS HAVE BEEN USED FOR CELESTIAL NAVIGATIONS AND
RELIGIOUS PRACTICES WITH MANY ANCIENT ASTRONOMERS
BELIEVING THEY WERE IMMUTABLE. THEY GROUPED THE STARS INTO
CONSTELLATIONS AND USED THEM TO TRACK PLANETS AND THE
INFERRED POSITION OF THE SUN.

6. IN 1913, THE HERTZSPRUNG-RUSSELL DIAGRAM WAS DEVELOPED
AND IN 1921 ALBERT MICHELSON MADE THE FIRST
MEASUREMENTS OF A STELLAR DIAMETER USING AN
INTERFEROMETER. IN 1925, CECILIA PAYNE FIRST PROPOSED THAT
STARS WERE PRIMARILY MADE OUT OF HYDROGEN AND HELIUM.
SINCE THEN, STARS HAVE BEEN CATEGORIZED INTO MANY
DIVISIONS, AND MANY MYSTERIES WERE REVEALED TO US. THE
SHEER VARIETY OF STARS IS SIMPLY OVERWHELMING.
IN 1913, THE HERTZSPRUNG-RUSSELL DIAGRAM WAS DEVELOPED
AND IN 1921 ALBERT MICHELSON MADE THE FIRST
MEASUREMENTS OF A STELLAR DIAMETER USING AN
INTERFEROMETER. IN 1925, CECILIA PAYNE FIRST PROPOSED THAT
STARS WERE PRIMARILY MADE OUT OF HYDROGEN AND HELIUM.
SINCE THEN, STARS HAVE BEEN CATEGORIZED INTO MANY
DIVISIONS, AND MANY MYSTERIES WERE REVEALED TO US. THE
SHEER VARIETY OF STARS IS SIMPLY OVERWHELMING.

7. FORMATION
STARS FORM IN HUGE CLOUDS OF GAS AND DUST. GRAVITY
CAUSES THESE CLOUDS TO CONTRACT THUS DRAWING THE GAS
CLOSER. AS THESE MATERIALS ACCUMULATE IN THE CENTER,
DENSITY RAISES AND PRESSURE INCREASES.
THIS CAUSES THE MATTER TO HEAT UP AND GLOW WHILE THE
MASS INCREASES. TEMPERATURES AND PRESSURE CONTINUALLY
GROW UNTIL HYDROGEN CAN BE FUSED. THE HEAT GENERATED BY
THIS NUCLEAR FUSION CAUSES THE GAS TO EXPAND AND WHEN
HYDROSTATIC EQUILIBRIUM IS REACHED, THE STAR IS BORN. MOST
STARS FORM IN GROUPS CALLED STAR CLUSTERS, MANY ARE
EVENTUALLY EJECTED FROM THESE CLUSTERS.