Department of Astronomy & Astrophysics
Villanova University
Villanova, PA 19085
(610) 519-4824 : Phone
(610) 519-6132 : FAX
Departmental (Official) Homepage
Some current (and continuing) research on the Young Stellar Object SU Aurigae:
Accreting Protoplanets Around the
Young Stellar Object SU Aurigae
Optical Image of SU Aurigae and its nearby companion AB Aurigae
The above image shows the young stellar object SU Aurigae and its companion AB Aurigae. Though faint nebulosity around both stars is noticeable, the photometric data presented here stems from deep within this surrounding dust and gas. The circumstellar accretion disk itself is evident in the data by the occurance of random "eclipse-like" events most likely due to the passage of a protoplanet or protocomet.
Artists' conception of a typical young stellar object
Shown above is an artists' conception of what a typical young stellar object may look like. The forming star is in the center and surrounding it is an extensive circumstellar disk of dust and gas. It is in this accretion disk that it is believed that planets will form. If the orientation of the disk is right, the "shadow" of a passing protoplanet with its associated cloud of material would be observed from the Earth.
Photometric evidence for the passage of protoplanets
The graph above shows five representative obscuration events. While there is no apparent regularity to these events, they all display similar morphology. These pronounced drops in the mean light (as much as 0.7 mag in the b-filter) are to be expected from an obscuring region within the circumstellar disk. Also note that the intensity sometimes plateaus briefly before and/or after the deepest part of the eclipse. If these are indeed protoplanetary bodies, they should be accompanied by a halo of accretion material or localized perturbation in the disk that would give rise to this partial drop in intensity.
Artists' conception of a forming planet around a forming star
In this picture the newly formed star is in the background. Much of the material that was once in the circumstellar disk has been swept up by the star and its forming planets, or pushed back into space by the energetic brilliance of the new star. Note that this picture shows a planet with a disk of material surrounding it. It is believed that planets form in much the same way that stars do - just on a smaller scale. It would be in this planetary accretion disk that its moons might form!
Copy of Poster presented at the AAS Meeting, Washington, D.C.