Peering to the Milky Way's far side

An artistic rendering of the Milky Way Galaxy.    
   Image NASA

An artistic rendering of the Milky Way Galaxy. Image NASA

In the case of the star-forming region called G007.47+00.05 at the other end of our galaxy, that would be "roughly equal to the angular size of a baseball on the Moon", according to a statement Thursday by the National Radio Astronomy Observatory (NRAO). "In terms of tracing and understanding the spiral structure, essentially half of the Milky Way is terra incognita". The last record for a parallax-based direct measurement was 36,000 light-years.

The astronomers used a time-honored distance-finding technique - trigonometric parallax - first used in 1838 to measure the distance to a star. Most of the stars and gas in our galaxy are within this newly-measured distance from the sun. Since we are inside the galaxy, it is hard for us to see its actual shape and structure, because that would require travelling hundreds of thousands of light-years, at the very least, to a distance from where the whole of the galaxy is visible face-on. With the VLBA, we now have the capability to measure enough distances to accurately trace the galaxy's spiral arms and learn their true shapes. You'll see your finger appear to shift with respect to background objects. Then they can use trigonometry to calculate the stars' distances.

Using the National Science Foundation's Very Long Baseline Array (VLBA), an interlinked system of 10 radio telescopes stretching across Hawaii, North America and the Caribbean, an worldwide team of astronomers have directly measured the distance to an object called G007.47+00.05, a star-forming region located on the opposite side of the galaxy from our solar system by looking for radio emissions from molecular gas clouds and massive, young stars, both of which typically reside in spiral arms. The smaller the angle, the greater the distance. This radio telescope system consists of 10 dish antennas distributed across North America, Hawaii, and the Caribbean.

The object that Dame and his colleagues measured is so far away that to determine its parallax, they had to measure it over the course of a whole year, taking observations at either side of Earth's orbit around the sun.

It has the ability to measure the minuscule angles associated with great distances.

Using VLBA to target star-forming regions within the galaxy allows us to circumvent that problem. Such regions include areas where molecules of water and methanol act as natural amplifiers of radio signals - masers, the radio-wave equivalent of lasers for light waves. This effect makes the radio signals bright and readily observable with radio telescopes. However, the idea of measuring the distance to star-forming regions like this one could help with the process of mapping. "We're looking all the way through the Milky Way, past its center, way out into the other side", MPIfR's Karl Menten said in the statement. Although we can peer along its edge while embedded in its disk, we cannot see what it looks like face-on.

Bottom line: Astronomers used parallax to obtain a direct measurement past the center of our galaxy, to the Milky Way's far side. This task will require many more observations and much painstaking work, but, the scientists say, the tools for the job now are in hand.

Within the next 10 years, we should have a fairly complete picture.

Notícias recomendadas

  • United Kingdom  bank Aldermore in talks over possible bid from S.Africa's FirstRand

    United Kingdom bank Aldermore in talks over possible bid from S.Africa's FirstRand

    FirstRand already has a fast-growing London-based auto finance business, Motonovo Finance. Aldermore's shares were up 15.7 percent at 296.7 pence at 1126 GMT.

    Uber fait appel de son interdiction à Londres

    Uber UBER.UL a fait appel vendredi de la suspension de sa licence à Londres, l'un de ses marchés les plus importants. Les 40.000 chauffeurs Uber de la capitale pourront ainsi continuer à conduire jusqu'au jugement final.
    Nouveau sponsor maillot pour l'OM

    Nouveau sponsor maillot pour l'OM

    En marge de l'annonce de la prolongation du partenariat avec la CEPAC, Jacques-Henri Eyraud a confié quelques mots au sujet du futur sponsor maillot de l'OM.
  • After second bungle, IRS suspends Equifax's

    After second bungle, IRS suspends Equifax's "taxpayer identity" contract

    The IRS has temporarily suspended its $7 million contract with Equifax following reports of new security issues. Late on October 12, the IRS said that it was temporarily suspending the contract, a move applauded by lawmakers.

    Sells 106500 Shares of First Horizon National Corp (FHN)

    Losch III sold 3,500 shares of First Horizon National Corporation stock in a transaction that occurred on Tuesday, September 26th. The stock of First Horizon National Corp (NYSE: FHN ) earned "Hold" rating by RBC Capital Markets on Thursday, September 7.
    FG Calls On Its International Allies To Starve IPOB of Funds

    FG Calls On Its International Allies To Starve IPOB of Funds

    Mohammed argued in the piece that IPOB's actions qualify the group as a terrorist organization in most jurisdictions. According to the minister, these statements credited to Kanu had exposed the group as a terrorist organisation.
  • Yellowstone's Supervolcano Could Blow Sooner Than We Thought

    Yellowstone's Supervolcano Could Blow Sooner Than We Thought

    According to ZME Science, Yellowstone has erupted at least three times ; the last time was approximately 630,000 years ago. The supervolcano has been analyzed by many research teams and independent volcanologists in the past.
    Get shot for the health of it

    Get shot for the health of it

    This year's shot offers protection against two influenza A viruses (an H1N1 and an H3N2 virus) and one influenza B virus. The flu spreads when a person comes into contact with droplets from an infected person who coughs or sneezes.
    Voici l'Aston Martin DB11 Volante (2017)

    Voici l'Aston Martin DB11 Volante (2017)

    Hormis le profil "fastback", la Volante conserve le design du coupé , y compris son aileron arrière mobile AeroBlade. Fixations Isofix à l'arrière de série et volant chauffant en option sont au catalogue pour une certaine polyvalence.
  • Amazon creates another 1200 jobs in the North West

    1200 jobs will be created at a new fulfilment centre in Bolton, bringing the total jobs created in the region to 3500. The retailer is also to open a new centre at Severn Beach, Bristol next year, also featuring Amazon Robotics.
    Amazon Partners With Microsoft to Release 'Gluon' Deep Learning Library

    Amazon Partners With Microsoft to Release 'Gluon' Deep Learning Library

    AWS and Microsoft published Gluon's reference specification so other deep learning engines can be integrated with the interface. Fourth, it provides these benefits without slowing down the training process.
    Officer Remigio's Daughters Remember Him Before Wake In Somerville

    Officer Remigio's Daughters Remember Him Before Wake In Somerville

    Remigio's daughters, Alexandra and Danielle, both in their 20s, lost their mother to a sudden illness past year . Remigio spent 30 years serving Somerville, and many say he has left his mark on the community.

We are pleased to provide this opportunity to share information, experiences and observations about what's in the news.
Some of the comments may be reprinted elsewhere in the site or in the newspaper.
Thank you for taking the time to offer your thoughts.