Optical follow-up of LOFAR transients

Optical follow-up of LOFAR transients

Vik Dhillon
LOFAR Transients Key Project Meeting, Meudon, December 2011



June 23, 2012


  1. New facilities for optical follow-up of LOFAR transients Vik Dhillon

  2. Contents •  pt5m - 0.5m robotic telescope on La Palma

    •  TNT – 2.4m Thai National Telescope
  3. pt5m •  CANARY: Laser Guide Star Multi-Object Adaptive Optics (LGS

    MOAO). •  ELT pathfinder. •  Needs to know the altitude of the dominant turbulent layer above the 4.2m William Herschel Telescope (WHT) in real time. •  pt5m: SLOpe Detection And Ranging (SLODAR). •  0.5m robotic telescope on WHT roof, with Shack-Hartmann wavefront sensor; PI: Richard Wilson (Durham).
  4. pt5m •  Telescope potentially idle for up to 50 weeks

    per year! •  Sheffield built a science camera for pt5m, in return for an equal- partner stake. •  First light in remote-control mode in June 2011. •  Robotic-control mode currently being commissioned.
  5. None
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  7. pt5m Specs: •  Lat: 17.88 W; Long: +28.76 N • 

    0.5m f/10 Modified Dall-Kirkham Reflector •  2148x1472 pixel CCD •  FoV 10.2’x6.9’, platescale 0.28”/pixel •  5 s dead-time between exposures •  UBVRI filter wheel •  Pointing to ~10” •  Slew speed ~20 deg/sec; clam-shell dome
  8. pt5m 5 sigma limiting magnitudes, UBVRI Bright Dark

  9. pt5m •  We’d like to make follow-up of LOFAR transients

    a priority. •  Small, fast, high-quality telescope at an excellent site. •  “Cheap” telescope time c.f. LT, so good for pointing at more marginal or brighter transients. •  Good for multi-colour, long-term monitoring observations once a transient has been discovered.
  10. https://sites.google.com/site/point5metre

  11. TNT •  Thai National Telescope. •  2.4m f/10 Ritchey-Chretien on

    Doi Inthanon (2,457m). •  High quality telescope (EOS), with 5- port Nasmyth focus. •  Dark site (in a national park) with excellent seeing (0.8”-0.9” median). •  Mainly use in 7-month dry season (Nov- May). •  Permanently mount ULTRASPEC on TNT in exchange for 30 nights per year.
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  13. ULTRASPEC •  ULTRASPEC is a high-speed camera, built by Sheffield/

    Warwick/UKATC. •  Used on EFOSC2 spectrograph on ESO3.6m and 3.5m NTT for 43 nights in 2007-2009. •  Shares data acquisition system with ULTRACAM. •  Uses a frame-transfer EMCCD, giving up to 100 Hz frame rates with zero readout noise.
  14. ULTRASPEC+TNT •  Re-imager (not spectroscopy!), giving 8’x8’ FoV and 0.45

    ”/pixel platescale. •  6-position wheel with u’g’r’i’z’ and clear filters. •  MoU signed with Thailand in 2011. Commissioning Autumn 2012. •  We would like to make follow-up of LOFAR transients a priority. •  Good for deep, high-speed photometry of faint transients. •  Not robotic, but manual overrides in our 30 night p.a. allocation (and DDT in the remaining time) possible.
  15. ULTRASPEC+TNT 5 sigma limiting magnitudes, UBVRIZ Dark Bright

  16. http://www.vikdhillon.staff.shef.ac.uk/ultraspec/ultraspec.html

  17. The End.