Variables and Transients
description
Transcript of Variables and Transients
Variables and TransientsThe exciting parts of the universe
Sydney Institute for Astronomy (SIfA)/ CAASTRO – The University of SydneyDr. Paul Hancock
(and occasionally the Sydney Observatory)
Transients are Extreme
› Transients include the- Brightest
- Fastest
- Hottest
- Most massive
- Most magnetized
› events in the universe.
› (also the weirdest)
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Bright objects are useful
3outreach.atnf.csiro.au/education/senior/cosmicengine/stars_luminosity.html
The cosmic distance ladder
4telescopes.stardate.org/research/cosmic_rulers/cds.php
Cephieds
5 J. Hartman (Harvard CfA) & K. Stanek (Ohio State U.)
Brighter than a Cephied
6commons.wikimedia.org/wiki/File:SN1994D.jpg
Type Ia Supernovae
7www.lbl.gov/Science-Articles/Archive/sabl/2005/October/04-supernovae.html
ned.ipac.caltech.edu/level5/March08/Frieman/Frieman3.html
Accelerating
Pulsars
8lempel.pagesperso-orange.fr/un_os_dans_le_crabe_uk.htm
Testing relativity
9hermes.aei.mpg.de/lrr/2003/5astronomy.swin.edu.au/cosmos/B/Binary+Pulsars
PeriastronC
umul
ativ
e sh
ift o
f per
iast
ron
time
(sec
onds
)
(Invisible) Gas in the Milky Way
10Susan Stolovy (SSC/Caltech) et al., JPL-Caltech, NASA
Moniez, 2003, A&A, 412, 105
Probing Interstellar Gas
11Feidler et al. 1994ApJ...430..581F Maitia et al. 2003ApJ...582..972M
Stellar evolution (simple)
12chandra.harvard.edu/edu/formal/stellar_ev/
Stellar interactions
13David Hardy/PPARC
Flaring stars
14http://sohowww.nascom.nasa.gov/pickoftheweek/old/17dec2010/
Black hole feeding
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Quasars
16painting by Don Dixon for Scientific American
Summary
› Transients and Variables offer us a unique probe of the universe
› Supernovae and variables stars allow us to measure distances
› Pulsars allow us to test general relativity
› Scintillation allows us to see invisible gas in the Milky Way
› Novae, and active stars allow us to understand the life cycle of stars
› Tidal disruption events allow us to study accretion disks and jets
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What are we doing now to find transients?
› Optical- PTF / SkyMapper
› Radio- MWA/LOFAR/MeerKAT/ASKAP
› X-ray/γ-ray- Swift/Fermi
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Current Optical Surveys
19www.astro.caltech.edu/palomar/scopes.html
Future optical surveys
20www.lsst.org
High energy surveys
21heasarc.nasa.gov/docs/swift/ www.esa.int/
Current Radio Surveys
22Top-foto, Assenwww.mwatelescope.org
Upcoming Radio Surveys
23www.ska.ac.za - Maik Wolleben
KAT-7 / MeerKAT
www.atnf.csiro.au/projects/askap/ - Terrace Photographers
ASKAP/Vast
The future of radio telescopes
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Summary
› We have many surveys and telescopes that can find transients
› The new surveys will give us a better understanding of the universe
› The new surveys produce MUCH more data than we have had before
› We need new ways to collect, organize and analyze the data
› We are now entering the era of "Time domain astronomy" and there will be many new and exciting discoveries over the next decade.
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Question Time!