1917 Astronomical Plate Reveals First-Ever Evidence Of Exoplanetary System
It pays to clean one's basement once in a while. A 1917 astronomical glass plate unearthed from the collections of Carnegie Observatories in Pasadena, California revealed the first-ever evidence of exoplanetary system.
According to Carnegie Science, the century-old plate featured an image of a white dwarf made way back in 1917 in what was then called the Mount Wilson Observatory in Los Angeles. This observatory is also owned by Carnegie. However, upon further inspection, there was more to this astronomical plate than just a stellar spectrum of the distant star.
Here's the backgrounder: Univerity College London researcher Jay Farihi made a request at the Carnegie Observatories for a material for his journal article. He was looking for the van Maanen's star, which was discovered by Dutch-American astronomer Adriaan van Maanen in the same year the plate was made.
In the 19th century, such stellar spectra images were helpful in developing a system of star classification. These images are recordings of light emitted by distant stars, such as the van Maanen, a white dwarf. These spectra can allow astronomers to know more about the chemical compositions of stars, as well as how the emitted light is affected by things it passes before we can see it from Earth.
Today, we use modern technology and digital tools to take images of stars.
As requested, the plate was produced by the Carnegie Observatories. Everything seemed normal until Farihi noticed something different in the so-called "absorption line," which can indicate areas where emitted light passes through something, indicating interference.
The astronomical plate showed heavy elements, such as iron, magnesium and calcium. Due to their weight, they should have disappeared into the star's interior, so their presence reveals that the van Maanen's and the other dwarf stars represent a type of planetary system.
These newly discovered systems are called "polluted white dwarves" due to the heavy elements around them, as per Mental Floss.
Perhaps, it would be best if the observatories and other museums would check their basement from time to time for more pleasant surprises. Who knows what other discoveries they might stumble upon?