An astronomer researching an article about planetary systems that orbit white dwarf stars made an extraordinary discovery when he examined a glass photographic plate from 1917, and found that it contained the first-ever evidence of a planetary system beyond our own Sun.
Before the advent of digital tools astronomers used the objective prism and glass photographic plates to record and analyze the spectra of, or the light emitted by, stars. By using a prism to split the light into different colors astrophysicists can infer many physical and chemical properties of stars and classify them into a logical sequence.
Jay Farihi, the author of the paper, asked the Carnegie Observatories for a plate in its archives that contained a spectrum of van Maanen’s star, a white dwarf discovered by Dutch-American astronomer Adriaan van Maanen, also in 1917.
Handwritten notes on the sleeve of the astronomical plate, made by observer Walter Adams, former Director of Mount Wilson Observatory.
When Farihi examined the spectrum of the star, he found that the "absorption line" on the spectrum indicated areas where the light coming from a star passed through something and had a particular color of light absorbed by that substance.
The 1917 photographic plate spectrum of van Maanen's star from the Carnegie Observatories’ archive. The pull-out box shows the strong lines of the element calcium, which are surprisingly easy to see in the century old spectrum. The spectrum is the thin, (mostly) dark line in the center of the image. The broad dark lanes above and below are from lamps used to calibrate wavelength, and are contrast-enhanced in the box to highlight the two “missing” absorption bands in the star.
The exoplanet also made itself known via the presence of heavier elements, such as calcium, magnesium, and iron in the spectrum, which are so heavy they should have long disappeared into the star's interior.
"The unexpected realization that this 1917 plate from our archive contains the earliest recorded evidence of a polluted white dwarf system is just incredible," said Carnegie Observatories’ Director, John Mulchaey.
"The fact that it was made by such a prominent astronomer in our history as Walter Adams enhances the excitement."
Van Maanen's star is one of several stars recently discovered to be "polluted white dwarf" systems, a type of planetary system in which a ring-shaped accumulation of planetary debris, produced during the white dwarf phase, orbits the star.
Jay Farihi said that while planets have not yet been detected orbiting van Maanen's star, nor around similar systems, such a discovery is only a matter of time.
"The mechanism that creates the rings of planetary debris, and the deposition onto the stellar atmosphere, requires the gravitational influence of full-fledged planets," Farihi explained.
"The process couldn’t occur unless there were planets there."
The fact of registration and authorization of users on Sputnik websites via users’ account or accounts on social networks indicates acceptance of these rules.
Users are obliged abide by national and international laws. Users are obliged to speak respectfully to the other participants in the discussion, readers and individuals referenced in the posts.
The websites’ administration has the right to delete comments made in languages other than the language of the majority of the websites’ content.
In all language versions of the sputniknews.com websites any comments posted can be edited.
A user comment will be deleted if it:
does not correspond with the subject of the post;
promotes hatred and discrimination on racial, ethnic, sexual, religious or social basis or violates the rights of minorities;
violates the rights of minors, causing them harm in any form, including moral damage;
contains ideas of extremist nature or calls for other illegal activities;
contains insults, threats to other users, individuals or specific organizations, denigrates dignity or undermines business reputations;
contains insults or messages expressing disrespect to Sputnik;
violates privacy, distributes personal data of third parties without their consent or violates privacy of correspondence;
describes or references scenes of violence, cruelty to animals;
contains information about methods of suicide, incites to commit suicide;
pursues commercial objectives, contains improper advertising, unlawful political advertisement or links to other online resources containing such information;
promotes products or services of third parties without proper authorization;
contains offensive language or profanity and its derivatives, as well as hints of the use of lexical items falling within this definition;
contains spam, advertises spamming, mass mailing services and promotes get-rich-quick schemes;
promotes the use of narcotic / psychotropic substances, provides information on their production and use;
contains links to viruses and malicious software;
is part of an organized action involving large volumes of comments with identical or similar content ("flash mob");
“floods” the discussion thread with a large number of incoherent or irrelevant messages;
violates etiquette, exhibiting any form of aggressive, humiliating or abusive behavior ("trolling");
doesn’t follow standard rules of the English language, for example, is typed fully or mostly in capital letters or isn’t broken down into sentences.
The administration has the right to block a user’s access to the page or delete a user’s account without notice if the user is in violation of these rules or if behavior indicating said violation is detected.