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The Venusian surface has been studied by measuring radar reflections and thermal radio emission over a wide spectral region of several centimeters to meter wavelengths from the Earth-based as well as orbiter platforms. The radiometric…

Earth and Planetary Astrophysics · Physics 2017-09-28 Nithin Mohan , Subhashis Roy , Govind Swarup , Divya Oberoi , Niruj Mohan Ramanujam , Suresh Raju C , Anil Bhardwaj

We report on the disk-averaged absolute brightness temperatures of Venus measured at four microwave frequency bands with the Cosmology Large Angular Scale Surveyor (CLASS). We measure temperatures of 432.3 $\pm$ 2.8 K, 355.6 $\pm$ 1.3 K,…

Using the Cosmology Large Angular Scale Surveyor, we measure the disk-averaged absolute Venus brightness temperature to be 432.3 $\pm$ 2.8 K and 355.6 $\pm$ 1.3 K in the Q and W frequency bands centered at 38.8 and 93.7 GHz, respectively.…

We present new estimates of the brightness temperatures of Jupiter, Saturn, Uranus, and Neptune based on the measurements carried in 2009--2013 by PLANCK/LFI at 30, 44, and 70 GHz and released to the public in 2018. This work extends the…

Terrestrial exoplanets orbiting within or near their host stars' habitable zone are potentially apt for life. It has been proposed that time-series measurements of reflected starlight from such planets will reveal their rotational period,…

Earth and Planetary Astrophysics · Physics 2020-11-25 Y. J. Lee , A. García Muñoz , T. Imamura , M. Yamada , T. Satoh , A. Yamazaki , S. Watanabe

High spectral resolution observations of Venus were obtained with the TEXES instrument at NASA's Infrared Telescope Facility. These observations focus on a CO$_2$ absorption feature at 791.4 cm$^{-1}$ as the shape of this absorption feature…

Earth and Planetary Astrophysics · Physics 2022-07-26 Rohini S Giles , Thomas K Greathouse , Patrick G J Irwin , Thérèse Encrenaz , Amanda Brecht

Solar light gets scattered at cloud top level in Venus' atmosphere, in the visible range, which corresponds to the altitude of 67 km. We present Doppler velocity measurements performed with the high resolution spectrometer MTR of the Solar…

Earth and Planetary Astrophysics · Physics 2010-11-12 P. Gaulme , F. -X Schmider , C. Grec , A. Lopez Ariste , T. Widemann , B. Gelly

Venus exhibits strong and changing contrasts at ultraviolet wavelengths apparently related to the clouds and the dynamics in the cloud layer, but to date their origin continues to be unknown. We investigate the nature of the UV contrasts…

Earth and Planetary Astrophysics · Physics 2025-02-10 Maarten Roos-Serote , Colin Wilson , Ryan MacDonald , Silvia Tellmann , Yeon Joo Lee , Igor Khatuntsev

On January 10 and 13, 2001, Venus was observed for the first time with an X-ray astronomy satellite. The observation, performed with the ACIS-I and LETG/ACIS-S instruments on Chandra, yielded data of high spatial, spectral, and temporal…

Astrophysics · Physics 2009-11-07 K. Dennerl , V. Burwitz , J. Englhauser , C. Lisse , S. Wolk

The presence of phosphine (PH$_3$) in the atmosphere of Venus was reported by Greaves et al. (2021a), based on observations of the J=1-0 transition at 267 GHz using ground-based, millimeter-wave spectroscopy. This unexpected discovery…

Parker Solar Probe (PSP) conducted several flybys of Venus while using Venus' gravity for orbital adjustments to enable its daring passes of the Sun. During these flybys, PSP turned to image the nightside of Venus using the Wide-field…

Earth and Planetary Astrophysics · Physics 2023-11-07 J. Lustig-Yaeger , N. R. Izenberg , M. S. Gilmore , L. C. Mayorga , E. M. May , A. Vourlidas , P. Hess , B. E. Wood , R. A. Howard , N. E. Raouafi , G. N. Arney

The planets Uranus and Neptune with small apparent diameters are primary calibration standards. We investigate their variability at ~90 GHz using archived data taken at the IRAM 30m telescope during the 20 years period 1985 to 2005. We…

Astrophysics · Physics 2009-11-13 C. Kramer , R. Moreno , A. Greve

On January 10 and 13, 2001, Venus was observed for the first time with an X-ray astronomy satellite. The observation, performed with the ACIS-I and LETG/ACIS-S instruments on Chandra, yielded data of high spatial, spectral, and temporal…

Astrophysics · Physics 2007-05-23 K. Dennerl , V. Burwitz , J. Englhauser , C. Lisse , S. Wolk

Thermal radiation becomes a prominent feature in the continuum spectrum of Venus longwards of $\sim$3 $\mu$m. The emission is traceable to the upper cloud and haze layers in the planet's mesosphere. Venus' thermal radiation spectrum is…

Earth and Planetary Astrophysics · Physics 2024-02-07 A. García Muñoz , P. Wolkenberg , A. Sánchez-Lavega , R. Hueso , I. Garate-Lopez

We study the spatial and temporal variability in Jupiter's atmosphere by comparing longitude-resolved brightness temperature maps from the Very Large Array (VLA) radio observatory and NASA's Juno spacecraft Microwave Radiometer (MWR) taken…

Earth and Planetary Astrophysics · Physics 2024-12-31 Joanna Hardesty , Chris Moeckel , Imke de Pater

Accurate calibration of data is essential for the current generation of CMB experiments. Using data from the Very Small Array (VSA), we describe procedures which will lead to an accuracy of 1 percent or better for experiments such as the…

The detection of the New Moon at sunset is of importance to communities based on the lunar calendar. This is traditionally undertaken with visual observations. We propose a radio method which allows a higher visibility of the Moon relative…

Instrumentation and Methods for Astrophysics · Physics 2014-03-05 Y. A. Hafez , L. Trojan , F. H. Albaqami , A. Z. Almutairi , R. D. Davies , C. Dickinson , L. Piccirillo

We present results from the first 22 GHz space very-long-baseline interferometric (VLBI) imaging observations of M87 by RadioAstron. As a part of the Nearby AGN Key Science Program, the source was observed in Feb 2014 at 22 GHz with 21…

The detection of phosphine (PH3) in the atmosphere of Venus has been recently reported based on millimeter-wave radio observations (Greaves et al. 2020), and its re-analyses (Greaves et al. 2021a/b). In this Matters Arising we perform an…

We present a study of water vapour in the Venus troposphere obtained by modelling specific water vapour absorption bands within the 1.18 \mu m window. We compare the results with the normal technique of obtaining the abundance by matching…

Earth and Planetary Astrophysics · Physics 2012-12-06 S. Chamberlain , J. A. Bailey , D. Crisp , V. S. Meadows
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