Where did Annie Cannon and Henrietta Leavitt work?
Harvard Computers at work, circa 1890, including Henrietta Swan Leavitt seated, third from left, with magnifying glass (1868–1921), Annie Jump Cannon (1863–1941), Williamina Fleming standing, at center (1857–1911), and Antonia Maury (1866–1952).
What did Henrietta Swan Leavitt discover in 1908 Why is this important?
Henrietta Swan Leavitt, (born July 4, 1868, Lancaster, Massachusetts, U.S.—died December 12, 1921, Cambridge, Massachusetts), American astronomer known for her discovery of the relationship between period and luminosity in Cepheid variables, pulsating stars that vary regularly in brightness in periods ranging from a …
How does the Leavitt law work?
It took years for the mostly-male astronomy community to realize that this relationship (today known as “the Leavitt Law”) means that measuring the period of a Cepheid variable immediately gives its true brightness — and furthermore, that comparing this to its apparent brightness immediately gives its distance.
What was Henrietta Swan Leavitt disability?
Leavitt studied math and the classics, traveled and taught before being hired by Pickering to measure star brightness through photometry. She, too, was nearly deaf.
How did Edwin Hubble determine the distance to galaxies?
From observations of the apparent magnitudes of the brightest stars in 14 more nebulae, Hubble estimated their distances. Comparing this value with the apparent magnitudes of the stars in four nebulae in the still more distant Virgo Cluster of galaxies, he determined their distance too.
Why are there no nearby quasars?
A: The simple answer: because luminous quasars are still visible from large distances, while fainter active galactic nuclei (AGNs) are not. Quasars are the highest luminosity (more than 100 billion times that of the Sun) and most massive (more than 100 million solar masses) subset of AGNs.
Who studied Cepheid stars?
Henrietta Swan Leavitt
Who discovered Cepheid stars?
What is the period of a Cepheid star?
The classical Cepheids have periods from about 1.5 days to more than 50 days and belong to the class of relatively young stars found largely in the spiral arms of galaxies and called Population I.
Why do Cepheid stars pulsate?
Pulsating variable stars are intrinsic variables as their variation in brightness is due to a physical change within the star. In the case of pulsating variables this is due to the periodic expansion and contraction of the surface layers of the stars.
What type of stars are most Cepheid variables?
Intrinsic variables. Cepheid Variables are very luminous stars, 500 to 300,000 times greater than the sun, with short periods of change that range from 1 to 100 days. They are pulsating variables that expand and shrink dramatically within a short period of time, following a specific pattern.
Which star takes longer to pulse?
star A-091 take longer to pulse than the other star. 2. Because both stars are in the same galaxy, they are about the same distance from Earth.
Do pulsating stars change color?
Stars with a pulse Scientists use a magnitude scale for star brightness. Besides changing brightness by 8 magnitudes, it also varies in color, appearing reddest when it is at its dimmest.
What type of stars have a shorter periods 4 hours to 1 day?
RR Lyrae stars have the following properties: Period = 4 hours to 1 day.
Are Bright Stars common?
Bright stars are exceedingly rare; the faintest stars are by far the most common.
What is the brightest thing in the universe?
Although quasars appear faint when viewed from Earth, they are visible from extreme distances, being the most luminous objects in the known universe. The brightest quasar in the sky is 3C 273 in the constellation of Virgo.
What is the name of the most beautiful star?
Sirius, also known as the Dog Star or Sirius A, is the brightest star in Earth’s night sky. The name means “glowing” in Greek — a fitting description, as only a few planets, the full moon and the International Space Station outshine this star.