Astronomers Discover A New Accurate Way For Measuring Distances Between Planetary Nebulae And The Earth

Three astronomers from the University of Hong Kong have found a way of estimating the distances between the so-called "planetary nebula"' and the earth more accurately. The study was led by Professor Quentin Parker, Dr. David Frew and Dr. Ivan Bojicic. It was issued in the Monthly Notices of the Royal Astronomical Society on Nov.18, 2015.

Science Daily reported that the researchers presented a solution on how to measure more accurately the distance between the "planetary nebulae" and the earth. They provided three sets of data. The first data involved the size of the object in the sky that is taken from the recent high-resolution survey. Second is the precise measurement of how intense the object is in red hydrogen-alpha emission line. The third set includes the approximation of dimming in the nebula that is caused by the interstellar reddening.

The developing "surface brightness-radius relation" has been strongly regulated utilizing over 300 planetary nebulae whose exact distances are measured through independent means such as trigonometric parallax.

Dr. David Frew, the first author of the study and the research assistant professor of the Department of Physics said that having discovered a new way to improve the distance estimates can provide more profound values for other key parameters in the field of science. The new distance scales is more than a factor of over than six powers of ten in surface brightness. It can stipulate distances that are accurate to about 20 percent.

Planetary Nebula is seen as the round shapes of planets, but they are in reality the glowing shell of ejected coverings of  dying stars. They are short-lived, lasting for a few tens of thousands of years. On the other hand, the typical stellar can live up to several billion years.

Planetary nebulae are examined by scientists in galaxies to find information on chemical abundances they contain. Recently, the Hubble Space Telescope has exposed many planetary nebulae that are characterized by extreme complexity and different morphologies.