Variables and TransientsThe exciting parts of the universe

Sydney Institute for Astronomy (SIfA)/ CAASTRO – The University of Sydney

Dr. 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 pe

riast

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!