Possible Variable Fine Structure Constant Tested On A White Dwarf Star

Scientists are using the Hubble Space Telescope and a White Dwarf Star (G191-B2B) to test if the Fine Structure Constant, or alpha (α) is not really constant.

The Fine Structure Constant is defined as the charge of an electron squared over the product of Planck's constant multiplied by the speed of light. The resulting value is 1/137 or 7.2973525698(24)×10⁻³.

This constant shows the probability of an electron absorbing a photon or simply the strength of the electromagnetic force exerted in an interaction. It relates to three important aspects of physics, electromagnetism, relativity, and quantum mechanics (through Planck's constant).

The importance of the Fine Structure Constant (α) relates to the existence of life. If the value of α is not as it is, life or intelligent life as it is now, would not exist. A 4% change in the value of α would mean that stellar fusion would not create carbon, making carbon based life impossible. If α were > 0.1, stellar fusion would be impossible and no place in the universe would be warm enough for life as we know it.

Using a white dwarf star with a gravity 30,000 times more than the Earth, scientists are measuring the strength of the electromagnetic force with the help of the Hubble Space Telescope. They will compare that value to that measured on Earth to determine if the Fine Structure Constant is really not constant and that it varies across the Universe.

White Dwarf Star Orbiting A Pulsar Discovered By ESO's VLT

Astronomers have used ESO’s Very Large Telescope, along with radio telescopes around the world, to find and study a bizarre stellar pair consisting of the most massive neutron star confirmed so far, orbited by a white dwarf star. This strange new binary allows tests of Einstein’s theory of gravity — general relativity — in ways that were not possible up to now. So far the new observations exactly agree with the predictions from general relativity and are inconsistent with some alternative theories. The results will appear in the journal Science on 26 April 2013.

Scientists using the European Southern Observatory's Very Large Telescope (VLT) has discovered an unusual pairing; a white dwarf star orbiting a neutron star (PSR J0348+0432). The neutron star is a pulsar around 20 kilometres across but is two times heavier than the Sun. This discovery and the observation of how the two stellar objects behave is how Einstein's Theory of General Relativity predicted it would behave.

A white dwarf star is a small star which is very dense and is mostly made up of electron-degenerate matter. It is a star that has reached the end of its normal life cycle and has stopped nuclear fusion (although some fusion reactions happen and can still generate energy). A white dwarf star may be as big as the Earth but has the same mass as that of the Sun.

A pulsar is a neutron star that is formed when a massive star's core is compressed during a super nova. This event collapses the core and forms the neutron star. Pulsars are extermely dense and highly magnetized. They rotate and emit a beam of electromagnetic radiation. This radiation is picked up as radio waves in the form of pulses. The name pulsar is abbreviated from the term "pulsating star".