Transcript Young Star Caught Speeding - Harvard

Young Star Caught Speeding
Alyssa A. Goodman
Harvard-Smithsonian Center for Astrophysics
Héctor G. Arce
Caltech
Star & Planet Formation
Galaxy
Molecular Cloud Complex
Star-Forming “Globule”
Disk + Jet
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Extrasolar System
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Star Cluster
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How fast is “22 km/s”?
45,000 miles per hour (45 x a speeding
bullet)
10-20 times faster than “most” stars move
Most stars
PV Ceph!
3 km/s
22 km/s
Velocity compared to local environment
“Homeland”
Exiled, but
Accepted in
New Land
NGC 7023
Ocean of
Emptiness
PV Ceph
“New
Land”
Goodman & Arce 2004, Figure 1
3 light years
Coming Soon
PV Ceph: The Movie
What’s an “HH knot”?
HH knots far from source
mark the ends of bipolar
“jets” or “outflows”
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Stanke, McCaughrean & Zinnecker, 1999
Goodman & Arce 2004, Figure 1
3 light years
Coming Soon
PV Ceph: The Movie
Simulated
Formation
of a Star
Cluster
Bate, Bonnell & Bromm 2002
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Optical Image of NGC 7023
Dust Emission Map
“Exit wound”
Tom Licha, 2002
Young Star
Caught
Speeding
Away from
Home
Goodman & Arce 2004
NGC 7023
PV Ceph
“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.
Optical Image of NGC 7023
First Evidence for a Young Star moving
at such High Speed far from a Cluster
Dust Emission Map
gap
NGC 7023
PV Ceph
Tom Licha, 2002
Young Star
Caught
Speeding Away
from Home
Speed=22 km/s
Age=0.5 million years
Goodman & Arce 2004
Optical Image of NGC 7023
First Evidence for a Young Star moving
at such High Speed far from a Cluster
Dust Emission Map
gap
NGC 7023
PV Ceph
Tom Licha, 2002
Young Star
Caught
Speeding Away
from Home
Speed=22 km/s
Age=0.5 million years
Goodman & Arce 2004
Deceleration of Jets
Variability in “Gyulbudaghain's Nebula”
(the fuzz surrounding PV Ceph)
July ‘98
Oct/Nov ‘98
Oct ‘00
In 1 year, PV Ceph moves about the distance from the Sun to Jupiter (5 A.U.)