Young Star Caught Speeding Alyssa A. Goodman Harvard-Smithsonian Center for Astrophysics Héctor G. Arce Caltech

Star & Planet Formation Galaxy Star Cluster Molecular Cloud Complex Star-Forming “Globule” Extrasolar System Disk + Jet

How fast is “22 km/s”? 45,000 miles per hour (45 x a speeding bullet) times faster than “most” stars move Most stars Velocity compared to local environment 3 km/s PV Ceph! 22 km/s

Exiled, but Accepted in New Land “Homeland” “NewLand” Ocean of Emptiness NGC 7023 PV Ceph

Coming Soon PV Ceph: The Movie 3 light years Goodman & Arce 2004, Figure 1

Stanke, McCaughrean & Zinnecker, 1999 What’s an “HH knot”? HH knots far from source mark the ends of bipolar “jets” or “outflows”

Coming Soon PV Ceph: The Movie 3 light years Goodman & Arce 2004, Figure 1

Simulated Formation of a Star Cluster Bate, Bonnell & Bromm 2002

Dust Emission Map Goodman & Arce 2004 NGC 7023 PV Ceph Optical Image of NGC 7023 Tom Licha, 2002 Young Star Caught Speeding Away from Home “Exit wound”

“Immigration” Happens This discovery was a surprise. Underage stars can run away from home, fast! A proper “speeding study” is needed to understand what stars formed where, as a function of time.

NGC 7023 PV Ceph Dust Emission Map Goodman & Arce 2004 Young Star Caught Speeding Away from Home First Evidence for a Young Star moving at such High Speed far from a Cluster Speed=22 km/s Age=0.5 million years gap Optical Image of NGC 7023 Tom Licha, 2002

NGC 7023 PV Ceph Dust Emission Map Goodman & Arce 2004 Young Star Caught Speeding Away from Home gap Optical Image of NGC 7023 Tom Licha, 2002 Deceleration of Jets First Evidence for a Young Star moving at such High Speed far from a Cluster Speed=22 km/s Age=0.5 million years

Clues Geometry of the “HH” knots Morphology of Molecular Outflow Morphology of Star-Forming “Blob” “Wiggle” of the Jet

The Most Subtle Evidence for PV Ceph’s Motion Goodman & Arce 2004 Each point shows position of emission peak in high-res molecular line map.

Deceleration Means Outflows Lie About their Age Goodman & Arce 2004

How often does this happen? Direct Proper Motion –RW Aur 16 km s -1, Jones & Herbig 1979 –BN object w.r.t. “I” 50 km s -1, Plambeck et al –IRAS km s -1, Loinard 2002 –T-Tau Sb 20 km s -1, Loinard et al Deduced from Outflow Morphology –B5 IRS1~10 km s -1, Bally et al. 1996* –Jets in NGC 1333 & Orion clusters ~10 km s -1 (Bally & Reipurth 2001) –PV Ceph 20 km s -1, Goodman & Arce 2004 *but the possibility of motion was not emphasized! See Furlan et al. 2003? New measurements say no

Variability in “Gyulbudaghain's Nebula” (the fuzz surrounding PV Ceph) July ‘98Oct/Nov ‘98Oct ‘00 In 1 year, PV Ceph moves about the distance from the Sun to Jupiter (5 A.U.)