When was spica

Sometimes, however, the mass determined from spectroscopy kinematics differs from that determined from evolutionary modeling. In the case of massive binary stars and Spica's two stars are both massive, at Enter CfA astronomer Dimitar Sasselov who is part of a team trying to resolve the mass discrepancy problem.

In previous work on massive binaries, the team found that the single-star evolutionary models were slightly in error, in particular for the smaller partner. For their analysis of Spica, the astronomers obtained high-quality spectra and broadband measurements over the course of nearly twenty-three days. They were able to refine all of the system parameters, and realized that the pulsations in the larger star are actually tidally induced, the first such case found for a massive binary. They also found, somewhat surprisingly, that there was no mass discrepancy problem for Spica - the stellar masses derived in both ways are actually consistent, although there are large uncertainties introduced by the complex nature of the Spica system.

The research program continues, and the astronomers plan to observe and analyze another few dozen systems in a consistent way, to improve their insights into the nature of the mass discrepancy problem for massive stars. Explore further. More from Astronomy and Astrophysics. Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page.

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You can unsubscribe at any time and we'll never share your details to third parties. It varies in brightness with a period of 0. Alpha Virginis B is cooler, smaller and less massive, with a temperature of 20, K, a radius 3.

It is a main sequence star of the spectral type B2V. It has a luminosity 2, times that of the Sun. Its projected rotational velocity is This is known as the Struve-Sahade effect. Both stars rotate more rapidly than their orbital period, and the lack of synchronization, coupled with the highly elliptical orbit, may indicate that the star system is still young.

A study published in revealed that Spica is a polarimetric variable. The two stars were the first to have their geometric albedo reflectivity measured. A study published in yielded geometric albedos of 3. Even though the stars reflect very little of the incident light, the reflected light is highly polarized. Spica is one of the 58 bright stars selected for navigation. Navigational stars play a special role in the field of celestial navigation because they are some of the brightest and most identifiable stars in the sky.

Spica is the only navigational star in the constellation Virgo. Spica lies only 2. Formation Spica is estimated to have formed around Location Spica is located in the zodiacal constellation of Virgo. The Future The primary Spica star is halfway between a subgiant and a giant on the evolutionary stage. Did you know? The best time to observe the stars and deep-sky objects situated in the Virgo constellation is during the month of May.

The best time to observe Spica, in particular, is from spring to late summer. It emerges on the horizon in the east-southeast at sunset in mid-April.

Spica moves at a speed of Many temples other than the one in Thebes were oriented towards Spica. Some of these temples are: The temple of the Sun at Tell el-Amarna 2. Since so many temples were oriented towards Spica, it is an indication that many cultures had knowledge of the precession of the equinoxes much earlier than Hipparchus documented his discovery.

Spica and the constellation of Virgo, are often associated with Demeter, and Dike, the goddess of justice in ancient Greek culture. The flag of Brazil is represented by 27 stars — each symbolizes a Brazilian Federative Unit. Spica is one of those stars and it represents the state of Para. Even though the two stars are separated by a distance greater than that between Earth and the Moon, they are also quite massive so they exhibit a strong gravitational pull on each other.

From Earth's point of view, the pair pass over each other just slightly in a grazing eclipse , which adds another source of variability. The association with spring is interesting as well, as Virgo first becomes visible in the evenings right around the spring equinox. In the s B. The temple had been constructed about 2, years prior and was thought to be oriented according to Spica's heliacal rising — the time of year when the star becomes briefly visible above the eastern horizon just before sunrise.

The route is rather a long one to trace, but a gentle curve will get you there. Why not go out and view Spica this spring? Save Dark Skies.