Stars of the universe

Stars of the universeBINARY AND VARIABLE STARS.

GALAXY, NEBULAE AND STAR CLUSTERS

HUGE MASS OF STARS SMALLEST GALAXY -100000 STARS LARGEST GALAXY-3000 BILLION STARS MILKY WAY SPIRAL GALAXY GALAXY ROTATING IN SPACE,WITH STARS

MOVING FASTER.

GALAXY

CLOUD OF DUST AND GAS EMISSION AND REFLECTION NEBULAE NEBULAE OF DYING STARS : PLANETARY

NEBULAE AND SUPERNOVA REMNANTS OPEN AND GLOBULAR CLUSTERS

NEBULAE AND STARS CLUSTERS

BC HIPPARCHUS’ CLASSIFICATION 6 GROUP CATEGORISATION 1ST GROUP- BRIGHTEST STARS 6TH GROUP-FAINTEST STARS 1ST MAGNITUDE STAR= 100 X 6TH

MAGNITUDE

STELLAR MAGNITUDE SEQUENCE

POGSON’S CALIBERATION

Bm/Bn=(n-m)Log2.512

LUMINOSITIES OF STAR

L = 4πr2 σ T4eff

COLOUR INDEX OF STAR

HOT STARS COOL STARS

SHORTER WAVELENGTH

HIGH TEMPERATURES EMITS MORE LIGHT OF

BLUE VIOLET

LONGER WAVELENGTH LOW TEMPERATURES EMITS MORE LIGHT OF

YELLOW RED COLOUR

KNOWLEDGE PROGRESSED IN TWO STEPS 1. MASS DETERMINATION 2.RELATIONSHIP BETWEEN MASS AND

LUMINOSITIES.

BINARY STARS

KINDS OF BINARY

1.VISUAL BINARY2.SPECTROSCOPIC BINARY

3. ECLIPSING BINARY

1867, JOHN STONEY’S THEORY MACMILLAN’S THOERY FISSION THEORY

ORIGIN OF BINARY STARS

FORMATION OF ROCHE LOBES FILLING OF ROCHE LOBE

MASS TRANSFER IN CLOSE BINARY SYSTEMS

WIDE SEPARATION IN ORBITS REVOLUTION OF FAINTER STAR ABOUT ITS

BRIGHTER COMPONENT WITH A COMMON CENTER OF GRAVITY.

ANGULAR SEPARATION AND THE POSITION ANGLE.

VISUAL BINARIES

VISUAL BINARY

ACCRETION DISK

SIRIUS SEEN BY HUBBLE TELESCOPE

SIRIUS (49.5 YEARS) CYGNI (720 YEARS) ᾳ-CENTURI (80 YEARS)

EXAMPLES

PICKERING’S OBSERVATION SHIFTING OF ABSORPTION LINES CLOSE STARS OF EQUAL BRIGHTNESS. DOPPLER SHIFTS- VELOCITY CURVES MASS- AMPLITUDE OF VELOCITY CURVE

RELATIONSHIP1. 2πrp = vpƮ2. 2πrs = vsƮ also,3. mp/ms = rs/rp = vs/vp

SPECTROSCOPIC BINARY

FIRST OBSERVED IN MIZAR SHORTEST PEROD OF REVOLUTION 1. VISUAL-4.5YEARS 2. SPECTROSCOPIC- FEW HOURS TO 150

DAYS.

EXAMPLE

PERIOD ECLIPSE OCCURRENCE TOTAL AND ANNULAR ECLIPSES BASED ON

SIZE OF STARS. CHANGE IN LIGHT INTENSITY.

ECLIPSING BINARIES

EXAMPLE- ALGOL

LIGHT CURVE OF ECLIPSING BINARY

STARS ORBITTING ARPOUND EMPTY SPACE NO VISIBLE COMPANION DIM,MASKED BY GLARE OF PRIMARY, EMITS

LITTLE OR NO RADIATION

ASTROMETRIC BINARIES

CENTRE OF MASS CALCULATION IN BINARIES

MOTION OF STARS AROUND COMMON BARYCENTRE

EQUAL MASSES

SMALL DIFFERENCE IN MASS

LARGE DIFFERENCE IN MASS

EXTREME MASS DIFFERENCE

SIMILAR MASSES ORBITTING IN ELLIPSE AROUND COMMON B.C.

INTRINSIC VARIABLES EXTRINSIC VARIABLES LIGHT CURVES DATA

1. BRIGHTNESS VARIATIONS PERIODICAL,SEMIPERIODICAL, IRREGULAR

2. SHAPE OF LIGHT CURVES

VARIABLE STARS

PULSATING- ALTERNATE EXPANSION & CONTRACTION

ERUPTIVE- ERUPTIONS AND FLARES ON SURFACE

CATACLYSMIC OR EXPLOSIVE VARIABLES

INTRINSIC VARIABLES

EFFECECLIPSING BINARIES, DOUBLE STARS ROTATING VARIABLES – (SUNSPOT TS)

EXTRINSIC VARIABLES

HERTZSPRUNG –RUSSELL DIAGRAM FOR INTRINSIC VARIABLES

CEPHEIDS-CLASSICAL CEPHEIDS, TYPE II, RR LYRAE, DELTA SCUTI ETC.

LONG PERIOD VARIABLES- MIRA, SEMIREGULAR, SLOW IRREGULAR

SLOW PULSATING B STARS RV TAURI ALPHA CYGNI PULSATING WHITE DWARFS

EXAMPLES

INFORMATION OF MASS, RADIUS, TEMPERATURE AND LUMINOSITY

UNDERSTANDING NATURE OF DIFFERENT STARS SYSTEMATIC ANALYZING- PHOTOGRAPHIC,

PHOTOELECTRIC AND CALIBERATED COUPLED DEVICE (CCD)

CEPHEID VARIABLES HELPS IN DETERMINING AGE OF UNIVERSE

CATACLYSMIC HELPS IN UNDERSTANDING ACTIVE GALAXIES AND SUPERMASSIVE BLACK HOLES.

RESEARCH ON STARS

THERE WILL ALWAYS BE SOME MYSTERIES HIDDEN WITHIN THE STARS AND THE ETERNAL QUEST TO COMPREHEND THE SPLENDOUR OF HEAVENS WILL NEVER CEASE