Although we see it from Earth as a single raised ribbon tracing the sky, our galaxy, Milky Way, consists of billions of objects so close together that they form that famous star trail, which, according to Greek mythology, was formed by milk spilled from the breast of Hera. For this reason, several projects have been launched in recent years aimed at its mapping and in-depth study. One of them was held in Chile with Overview of the Dark Energy Chamber Plane (DECaPS2)located in the city Victor M. Blanco telescopefrom Cerro Tololo Inter-American Observatory, in Chile. The first batch of data was submitted in 2017 and a new one has just been published describing more 3.3 trillion celestial objectswith unprecedented precision.
The device used was originally intended to study dark energy. This started in 2013 and was completed in 2019, but DECaPS2 continued to be used for other purposes such as developing this map of the Milky Way.
A map that, in fact, can be seen in the open air by both specialists and amateur astronomers. For the latter, the data is quite complex; but at least they can enjoy looking at captivating images.
Accurate map of the Milky Way
study deeply Milky Way presents several obstacles. First, most of the stars and dust in the galaxy concentrating on your record. That is, a bright band from which spiral arms are born. This is a problem because “the dark tentacles of dust seen in the image are absorbing starlight and they completely erase the weakest“. In addition diffuse nebulae interfere with the measurement of the brightness of other objects. Finally, there are so many stars that they are located one above the other, and it is very difficult to observe each of them separately.
But DECaPS2 has two tricks up its sleeve to overcome all these obstacles. On the one hand, his ability observe in the near infraredor allows you to penetrate beyond the dust that absorbs light. Speaking very metaphorically, he removes the veil that covers all those stars that usually remain hidden from other instruments.
On the other hand, he has new approach to data processing, which allows much better prediction of the background behind each star. Result as explained in the statement Debra FisherDirector of the Department of Astronomical Sciences at the US National Science Foundation, it’s like taking a picture of more than 3 billion people, and each of them is recognizable.
More than 6.5% of the sky is covered.
If we add the data presented in 2017 to the latter, then the overall map already covers 6.5% of the night sky and covers a longitude of 130º, which is 13,000 times the angular area of the full moon.
In general, scientists 10 terabytes of data from 21,400 individual exposures.. Thus, the 3.3 billion described objects make up what is believed to be the largest catalog of the Milky Way compiled to date.
This does not mean that they represent the total number of objects in our galaxy. No doubt there are many more. Now, at least, we know that there are instruments capable of moving through Hera’s milk stream, capturing and cataloging every drop of it.
Source: Hiper Textual