Transit of Venus ObservationsFrom National Solar Observatory
National Solar Observatory Facilities
Dunn Solar TelescopeSunspot, New Mexico, USAD = 76cm, λ=380-1700 nm
McMath-Pierce TelescopeKitt Peak, Arizona, USA
D = 160 cm, λ=1000-5000 nm
Transit Conditions – Sacramento Peak
Interferometric BIdimensional Spectrometer (IBIS)
Dual Fabry-Perot Imaging SpectrometerP.I. - Fabio Cavallini (INAF/Arcetri)
Facility Instrument at the NSO/Dunn Solar Telescope since 2005
Publication List: http://tinyurl.com/ibis-pubs
Instrument Design: Cavallini, F., 2006, Solar Phys., 236, 415.Spectral Profile: Reardon, K., Cavallini, F., 2008, A & A, 481, 897.MTF: Righini, A., Cavallini, F., Reardon, K., 2010, A & A, 515, 85.
Refe
rence
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Spectral Range: 5400 - 8600 ÅFWHM: 20-45 mÅFOV: 98 x 98 arcsecPixel Size: 0.098 arcsec2/pixelExposure Times: 20-50 msecStrehl Ratio: ~0.95Frame Rate: 8 – 12 frames/secData Rate: ≥ 100 GB/hour (two CCD’s)
Application of post-facto image correction techniques:• Destretching• Speckle Reconstruction• Multi-Object Multi-Frame Blind Deconvolution
Available Filters
Interferometric BIdimensional Spectrometer (IBIS)
Spectral resolution ~200,000 – 260,000
Mercury Transit – 06 November 2006Hα Imaging at Ingress
IBIS/DST
Mercury Transit – 06 November 2006 – IBIS/DST
Imaging Spectroscopy of planetary transit
Na D2 589.0 nm : Scan range = 1.5 Å : Δλ = 0.009 Å0.083 arcsec/pixel
EquivalentWidth
GaussianWidth
GaussianAmplitude
GaussianShift
Mercury Transit – 06 November 2006IBIS/DST Observations of Mercury Exosphere in Na
D2
IBIS Field of View
98 x 98 arcsecMercury
d=10”
98 x 98 arcsecVenusD=60”
IBIS Field of View
• Upper wavelength limit of 8700 Å• Need strongest line to improve SNR• Need to minimize contamination from other solar or
terrestrial spectral lines• Pascal Hedelt simulated Venus CO2 absorption
spectrum from 780 – 4500 nm• Compared simulated spectrum (corrected from
vacuum to air wavelengths!) to solar atlas
Spectral Line Selection for IBIS
Solar + terrestrial atlas spectrumSimulated Cytherian CO2 spectrum
Spectra at 870 nm – Noisy Continuum!
Solar, Terrestrial, Cytherian Spectra – 780 nm
Solar + terrestrial atlas spectrumSimulated Cytherian CO2 spectrum
Solar + terrestrial atlas spectrumSimulated Cytherian CO2 spectrum
IBIS Prefilter Profile
Solar, Terrestrial, Cytherian Spectra
Imaging of AureoleRapid Oscillations of the Solar Atmosphere
(ROSA)http://star.pst.qub.ac.uk/rosa/
Six Andor 1000 x 1000 pixel CCD’s, 30 frames/sec sustained+ image reconstruction techniques
Will use ROSA to take multiwavelength observations (380 – 500 nm) at high cadence during ingress
Look for wavelength dependence of aureole due to scattering processes
Possible addition of 2k x 2k, 50 fps detector
For higher cadence and resolution
Facility Infrared Imaging Spectrograph(FIRS)
Spectral coverage: ~60 Å (λ/250)
Slit length
Slit scanning
Full Stokes Spectropolarimetry
Observe same spectral interval as Hedelt et al. 2011?
McMath-Pierce TelescopeNSO Array Camera (NAC)
1024 x 1024, helium cooled, InSb array
Spectral Range: 1.6 –2.5 μm, 4.67 μmSpectral Resolution: ~50,000 – 70,000Spectral coverage: ~60 Å
Full Stokes Spectropolarimetry
Spectral interval(s) to observe?1.6 and/or 2.2 μm bands