Astronomers say they have finally pinned down the distance to a famous cluster of stars called the Pleiades. Their discovery overturns measurements made by the cosmic-mapping satellite Hipparcos, and may settle a controversy that challenges our understanding of how stars form and evolve. Read more
The cluster of stars known as Matariki in New Zealand are a prominent sight in the night sky from most parts of the globe, and they hold special significance to different cultures worldwide. Known as the Pleiades, or the seven sisters, to the ancient Greeks, and as Matalii, Makalii, Mataliki and Mataiki in other Polynesian cultures, legends about the cluster abound. Every year during May, Matariki is obscured by the Suns glare and disappears from view for about a month. Its reappearance in the pre-dawn sky in early June, coupled with the first crescent Moon of the period, signals the Maori New Year and the beginning of the Matariki festival. Ancient Mori measured the passing of time and seasons using a lunar calendar. Each monthly cycle of the Moon is 29.53 days, this leaves the year about 11 days short of the 365-day solar year, so each year it needs to be re-set using the stars to prevent the seasons slipping. Most Maori achieved this by re-starting the year with reference to the first reappearance of Matariki from behind the Sun in the early dawn sky. Read more
Title: Toward a VLBI resolution of the Pleiades distance controversy Authors: Carl Melis, M. J. Reid, A. J. Mioduszewski, J. R. Stauffer, G. C. Bower
The Pleiades is the best studied open cluster in the sky. It is one of the primary open clusters used to define the 'zero-age main sequence,' and hence it serves as a cornerstone for programs which use main-sequence fitting to derive distances. This role is called into question by the 'Pleiades distance controversy' - the distance to the Pleiades from Hipparcos of approximately 120 pc is significantly different from the distance of 133 pc derived from other techniques. To resolve this issue, we plan to use Very Long Baseline Interferometry to derive a new, independent trigonometric parallax distance to the Pleiades. In these proceedings we present our observational program and report some preliminary results.
Alcyone is a star system in the constellation Taurus. It is the brightest star in the Pleiades open cluster, which is a young cluster, aged at less than 50 million years. Alcyone is approximately 370 light years from Earth. It is named after the mythological figure Alcyone, one of the mythological Pleiades. Read more