Transit of Venus Observations From National Solar Observatory

National Solar Observatory Facilities Dunn Solar Telescope Sunspot, New Mexico, USA D = 76cm, λ= nm McMath-Pierce Telescope Kitt Peak, Arizona, USA D = 160 cm, λ= nm

Transit Conditions – Sacramento Peak

Interferometric BIdimensional Spectrometer (IBIS) Dual Fabry-Perot Imaging Spectrometer P.I. - Fabio Cavallini (INAF/Arcetri) Facility Instrument at the NSO/Dunn Solar Telescope since 2005 Publication List: 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. References

Spectral Range: Å FWHM:20-45 mÅ FOV:98 x 98 arcsec Pixel Size: arcsec 2 /pixel Exposure Times:20-50 msec Strehl Ratio: ~0.95 Frame Rate: 8 – 12 frames/sec Data Rate:≥ 100 GB/hour (two CCD’s) Application of post-facto image correction techniques: Destretching Speckle Reconstruction Multi-Object Multi-Frame Blind Deconvolution – Fe I [g=0] – Fe I (SDO/HMI) 630.1/630.2 – Fe I – Ni I (MDI ; GONG) – Fe I [g=0] – Fe II [g=0] – He I D – Na D – Na D – H  – Ca II Available Filters Interferometric BIdimensional Spectrometer (IBIS) Spectral resolution ~200,000 – 260,000

Mercury Transit – 06 November 2006 Hα Imaging at Ingress IBIS/DST

Mercury Transit – 06 November 2006 – IBIS/DST Imaging Spectroscopy of planetary transit Na D nm : Scan range = 1.5 Å : Δλ = Å arcsec/pixel

Equivalent Width Gaussian Width Gaussian Amplitude Gaussian Shift Mercury Transit – 06 November 2006 IBIS/DST Observations of Mercury Exosphere in Na D 2

IBIS Field of View 98 x 98 arcsec Mercury d=10”

98 x 98 arcsec Venus D=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 spectrum Simulated Cytherian CO 2 spectrum Spectra at 870 nm – Noisy Continuum!

Solar, Terrestrial, Cytherian Spectra – 780 nm Solar + terrestrial atlas spectrum Simulated Cytherian CO 2 spectrum

Solar + terrestrial atlas spectrum Simulated Cytherian CO 2 spectrum IBIS Prefilter Profile Solar, Terrestrial, Cytherian Spectra

Imaging of Aureole Rapid Oscillations of the Solar Atmosphere (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 Telescope NSO Array Camera (NAC) 1024 x 1024, helium cooled, InSb array Spectral Range: 1.6 –2.5 μm, 4.67 μm Spectral Resolution: ~50,000 – 70,000 Spectral coverage: ~60 Å Full Stokes Spectropolarimetry Spectral interval(s) to observe? 1.6 and/or 2.2 μm bands