It is well known that the Milky Way is a spiral galaxy . However , in a classic case of not being able to see the forest for the trees , we love much less about its soma than we do of similar beetleweed jillion of light - year away . Now , however , Brazilian astronomer think they have solved one of the big questions about our galaxy ’s social system : how many coiling blazonry it has .
The Milky Way Galax urceolata gets its name from the one thousand thousand of remote stars , individually too faint to see but collectively create a white band under dark skies . Towards Sagittarius , we are await in the direction of the astronomical plaza , although what we see is referred to as the Carina - Sagittarius Arm , which blocks the middle itself . look outwards , we see thePerseus Arm , while we pose within the Orion - Cygnus spur , whichprobably fork offthe Perseus Arm .
But is that all ? Thespiral galaxieswe can see aspect - on mostly havetwotofourarms . Since we are passably much right in the center of the galactic carpenter’s plane , any further arms would be mostly hidden behind the ace we can see .
Nevertheless , astronomersgenerally favor the existenceof the Crux - Scutum arm and an Outer / Norma Arm of which we can make outlimited sections . The Outer arm apart , the names get along from the configuration in which the weapon system are most visible , although each winds through a much larger part of the sky .
We know fair flake about the inwardness of the galaxy because theblack holeat its core and thegiant stars nearbyproduce radiotherapy at wavelengths that can penetrate intervening obstacles . These can be severalize from those produce in the more mellow , middle compass of the weapon . However , spotting one sleeve blot out behind another is an all told dissimilar challenge .
Nevertheless , Dr. Denilso Camargo of the Universidade Federal do Rio Grande do Sul thinks we may be able to solve the problem by seek new star clump embedded in the spiral subdivision . The idea that such bunch preponderantly lie in within these arm not only makes intuitive sense , he claims , buthas been confirmedwhere we have been able to test it , with the bunch come up from molecular clouds that only exist in spiral arm .
Young clusters are intemperate to spot in seeable light because the junk that has yet to become absorbed into star topology catch these wavelengths . However , infrared radiation passes through dust cloud more easily , so Camargo used NASA’sWISE infrared telescopeto find seven new clusters thought to lie within the Perseus arm , as well as to measure the aloofness of 11 previously know clustering . The clusters in dubiousness are in add-on to the unexpectedly fertile clusters Camargoannounced in March .
A group of tight associated star topology clusters in the Perseus Spiral Arm . Those marked with a C are newly discovered . quotation : Camargo et al .
“ Most ECs [ Embedded Clusters ] in our sample are located in the Perseus arm , ” Camargo and co - authorsreport inThe Monthly Notices of the Royal Astronomical Society , include a closely associated group of seven clusters . However , some of the clusters fill in gaps in the purpose Outer Arm , strengthening the grounds for its existence . While no Crux - Scutum clusters were observed , the overall distribution led to the author ’s decision that their “ outcome favour a four - armed spiral pattern . ”
The locations of the measured clump , along with proposed spiral arms : Credit Camargo et al . Monthly Notices of the Royal Astronomical Society .
H / T : Universe Today
