Hover your mouse over each blue dot for the name of the object, or click on the dot for a detail page. This map was created using the all-sky hydrogen-alpha map produced by Douglas Finkbeiner from data collected by the WHAM, VTSS and SHASSA hydrogen-alpha surveys.
The Ara OB1A and adjacent Scorpius OB1 - west, Scorpius OB1 - east and Eagle/Omega regions are massive molecular cloud and star formation areas located immediately across a large gap inwards from the Orion Arc. These areas are often considered to be part of the Sagittarius Arm of the Milky Way, although some astronomers argue that these molecular clouds are not part of an arm as they do not form an arc-like density wave. (See articles by Anna Mel'nik here and here for more details.)