Monitoring Neptune's atmosphere with a combination of small and large telescopes

2020 ◽  
Author(s):  
Ricardo Hueso ◽  
Imke de Pater ◽  
Amy Simon ◽  
Mike Wong ◽  
Larry Sromovsky ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
Vertical Wind Shear ◽  
Apparent Size ◽  
Absorption Bands ◽  
High Resolution Data ◽  
Cloud Systems ◽  
Methane Absorption ◽  
Large Telescopes

<p>Neptune’s atmosphere is covered by tropospheric clouds and elevated hazes that are highly contrasted in hydrogen and methane absorption bands that dominate the red and near-infrared spectrum of the planet. The major cloud systems observed in these wavelengths evolve in time-scales of days, months and years. However, the differential rotation of the atmosphere, and the vertical wind shear implied by the motion of some of these systems, result in challenges in identifying common cloud systems observed in images obtained with a time difference of only a few weeks. Given the small apparent size of Neptune’s disk (2.3 arc sec at best) there are outstanding difficulties in obtaining sufficient high-resolution data to trace Neptune’s atmospheric dynamics and study the variability in the atmosphere.</p><p>In 2019 Neptune has been observed by a battery of different large telescopes and techniques including: Adaptive Optics observations from the Keck, Lick and other telescopes, observations from Hubble Space Telescope in two different dates, and lucky-imaging observations with the GranTeCan 10.4m, Calar Alto 2.2m and the 1.05m Pic du Midi telescope. In addition, some ground-based observers using small telescopes of 30-40 cm have been successful to image Neptune’s major clouds completing a dense time-line of observations. We will present comparative results of Neptune’s major cloud systems observed with these facilities at a variety of spatial resolutions and long-term drift rates of some of these cloud systems. These will be compared with similar multi-telescope results obtained in the past with several of these telescopes since 2015. Future punctual observations achievable with new observational facilities such as the JWST will benefit from ground-based coordinated campaigns and will require a combination of several telescopes to understand drift rates and evolutionary time-lines of major cloud systems in Neptune.</p>

Monitoring Neptune's atmosphere with small and large telescopes: results for 2019

2020 ◽  
Author(s):  
Ricardo Hueso ◽  
Imke de Pater ◽  
Erandi Chavez ◽  
Amy Simon ◽  
Larry Sromovsky ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Late Summer ◽  
Life Time ◽  
Space Science ◽  
The South ◽  
Absorption Bands ◽  
Single Observation ◽  
Cloud Systems ◽  
Meteorological Systems

<p>Neptune’s atmosphere is highly dynamic with atmospheric systems observable as bands and discrete cloud systems that evolve in time scales of days, weeks and years. Most of them are observed as tropospheric clouds and elevated hazes that appear highly contrasted in observations obtained in hydrogen and methane absorption bands in the red and near-infrared spectrum of the planet. Given the small size of Neptune as observed from Earth (2.3 arcsec), it is difficult to characterize most of these clouds. Basic questions such as if they are convective storms, vortices or clouds detached from atmospheric waves or bands can be difficult for an specific feature in a given observation [1]. Only Adaptive Optics or lucky-imaging instruments in 8-m telescopes or larger, and HST, can provide suitable data, but the difficulty to access enough observational time in these facilities suggests that a combination of data from several observing programs can help. Smaller telescopes can also play an important role since they can be used to follow the main cloud systems and cover the gaps between observations obtained by the larger telescopes. This can provide the life-time or drift rates of the largest meteorological systems allowing to compare observations of the same features observed months apart in the largest telescopes.</p> <p>During the last few years we have combined observations obtained from a variety of telescopes to study the major cloud systems and understand their life-time and evolution [2, 3], including those of “companion” clouds linked to rare dark vortices that are only observable in blue wavelengths from space [2, 4, 5]. In this work we present our data for 2019 which consists of the following observations:</p> <ul> <li>HST observations from the Outer Planets Atmospheres Legacy program (OPAL).</li> <li>Several sets from Keck and Lick telescopes from different programs including some relatively frequent observations from the TWILIGHT program.</li> <li>GTC observations with the HiperCam instrument doing lucky-imaging.</li> <li>Calar Alto 2.2m telescope with the PlanetCam lucky-imaging instrument.</li> <li>One single observation from Gemini while testing an AO system.</li> <li>Additional observations from the Pic du Midi 1.05 m telescope.</li> <li>Images provided by amateur astronomers and available through the PVOL [6] database.</li> </ul> <p>The combination of these data suggests more variability and less cloud activity in 2019 than in previous years with a lower number of features in the data sets obtained with smaller telescopes. We provide the identification of particular meteorological systems over late summer 2019 and present drift rates of different mid-latitude features in the south hemisphere that are close but separated enough to the Voyager zonal winds to deserve attention. Other cloud systems in the south polar region and north tropics seem to follow the Voyager wind profile.</p> <p>Future punctual observations achievable with new observational facilities such as the JWST will benefit from the evolutionary time-lines of the major cloud systems of Neptune and their drift rates in the atmosphere provided by similar future campaigns.</p> <p><strong>References</strong></p> <p>[1] Hueso and Sánchez-Lavega, Atmospheric Dynamics and Vertical Structure of Uranus and Neptune's weather layers. Space Science Reviews, 2019.</p> <p>[2] Hueso et al., Neptune long-lived atmospheric features in 2013-2015 from small (28-cm) to large (10-m) telescopes. Icarus, 2017.</p> <p>[3] Molter et al., Analysis of Neptune's 2017 Bright Equatorial Storm, Icarus, 2019.</p> <p>[4] Wong et al., A New Dark vortex on Neptune, The Astronomical Journal, 2018.</p> <p>[5] Hsu et al., Lifetimes and Occurrence Rates of Dark Vortices on Neptune from 25 Years of Hubble Space Telescope Images, The Astronomical Journal, 2018.</p> <p>[6] Hueso et al., The Planetary Virtual Observatory and Laboratory (PVOL) and its integration into the Virtual European Solar and Planetary Access (VESPA), Planetary Space Science, 2018.</p>

Variations in spectral reflectivity and vertical cloud structure of Jupiter’s Great Red Spot

2021 ◽  
Author(s):  
Asier Anguiano-Arteaga ◽  
Santiago Pérez-Hoyos ◽  
Agustín Sánchez-Lavega ◽  
Patrick G.J. Irwin
Keyword(s):  
Near Infrared ◽  
Hubble Space Telescope ◽  
Temporal Variations ◽  
Wide Field ◽  
Absorption Bands ◽  
Spectral Reflectivity ◽  
Methane Absorption ◽  
Cross Calibration ◽  
Calibrated Images ◽  
Atmospheric Phenomena

<p>The Great Red Spot (GRS) of Jupiter is a large anticyclonic vortex present in the Jovian atmosphere. First observed in the XVII century, it is almost constantly located at 22°S and it is arguably one of the main atmospheric phenomena in the Solar System. Despite having been widely studied, the nature of the chromophore species that provide its characteristic colour to the GRS’s upper clouds and hazes is still unclear, as well as its creation and destruction mechanisms.</p><p>In this work we have analysed images provided by the Hubble Space Telescope’s Wide Field Camera 3 between 2015 and 2019, with a spectral coverage from the ultraviolet to the near infrared, including two methane absorption bands. These images have undergone a photometric process of cross calibration, ensuring a consistent correlation among the images corresponding to different visits and years. From such calibrated images, we have obtained the spectral reflectivity of the GRS and its surroundings, with particular emphasis on a few, dynamically interesting regions.</p><p>We used the NEMESIS radiative transfer suite to retrieve the main atmospheric parameters (particle vertical and size distributions, refractive indices…) that are able to explain the observed spectral reflectivity of the selected regions. Here we report the spatial and temporal variations on such parameters and their implications on the GRS overall dynamics.</p>

Variations in spectral reflectivity and vertical cloud structure of Jupiter’s Great Red Spot

2020 ◽  
Author(s):  
Asier Anguiano-Arteaga ◽  
Santiago Pérez-Hoyos ◽  
Agustín Sánchez-Lavega
Keyword(s):  
Radiative Transfer ◽  
San Francisco ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
Average Rate ◽  
Strong Interactions ◽  
Absorption Bands ◽  
Spectral Reflectivity ◽  
Methane Absorption ◽  
Different Depths

<p>The Great Red Spot (GRS) of Jupiter is a large anticyclonic vortex present in the Jovian atmosphere. First observed in the XVII century, it is almost constantly located at 22°S. Since its discovery it has gradually decreased in size at an average rate of 170 km/year in longitude and 60 km/year in latitude. The nature of the chromophore species that provide its characteristic color to the GRS’s upper clouds and hazes is still largely unknown, as well as its creation and destruction mechanisms. During year 2019, the GRS began to lose some of this reddish material as a consequence of the interaction with other vortices present in nearby latitudes, raising serious doubts about its possible disappearance (Sánchez-Lavega et al., 2019).</p> <p>In this work we have analyzed images provided by the Hubble Space Telescope between 2015 and 2019, with a spectral coverage from the ultraviolet to the near infrared, including some methane absorption bands of different depths. These images have been calibrated in absolute reflectivity, and from them we have obtained the spectral variations in brightness that occur in different dynamically interesting regions of the GRS and its surroundings.</p> <p>The spectral reflectivity of the studied regions over the mentioned years has been analyzed using the NEMESIS radiative transfer code (Irwin et al., 2008). In this way it has been possible to retrieve the main features playing a key role in the spectral reflectivity of GRS’s upper clouds and hazes, such as particle size distribution, refractive indexes and optical thickness. At the same time, this analysis has provided the vertical distribution of particles for pressure levels above 1 bar, allowing a comparative study of its evolution over recent years.</p> <p><strong>References</strong></p> <p>-Irwin, P. G. J., Teanby, N. A., de Kok, R., Fletcher, L. N., Howett, C. J. A., Tsang, C. C. C., . . . Parrish, P. D. (2008, April). The NEMESIS planetary atmosphere radiative transfer and retrieval tool. <em>Journal of Quant. Spec. and Radiative Transfer</em>, 109, 1136-1150. doi: 10.1016/j.jqsrt.2007.11.006</p> <p>- Sánchez-Lavega, A., Iñurrigarro, P., Anguiano-Arteaga, A., Garcia-Melendo, E., Legarreta, J., Hueso, R., Sanz-Requena, J.F., Pérez-Hoyos, S.,  Mendikoa, I., Soria, M., Rojas, J.F. Jupiter’s Great Red Spot threatened along 2019 by strong interactions with close anticyclones, AGU Fall Meeting, P44A-01, San Francisco, 12 December 2019</p>

scholarly journals Adaptive Optics: Performance and Limitations

1994 ◽  
Vol 158 ◽  
pp. 273-281
Author(s):  
Francois Roddier
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Image Improvement ◽  
Large Telescopes

Adaptive optics systems are now being developed for astronomical applications. On large telescopes, a substantial image improvement can be obtained in the near infrared, using natural guide stars.

scholarly journals 9.5. The “double nucleus” of M31 in J, H, and K

1998 ◽  
Vol 184 ◽  
pp. 391-392
Author(s):  
P. Hinz ◽  
K. Hege ◽  
D. McCarthy ◽  
M. Lloyd-Hart ◽  
F. Melia
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Blind Deconvolution ◽  
Hubble Space Telescope ◽  
Wiener Filter ◽  
Diffraction Limit ◽  
Infrared Observations ◽  
Double Nucleus ◽  
Filter Algorithms ◽  
Adaptive Optics System

Hubble Space Telescope images of the nucleus of M31 show a double-peaked structure with the primary peak being offset from the center by approximately 0.5″. We observed the central 13″ of M31 in the J, H, and Ks passbands to determine the nuclear structure in the near-infrared. Observations were taken at the MMT Observatory, using a low-order adaptive optics system, FASTTRAC II (Gray et. al. 1995). The diffraction limit for the system is 0.25″ in K band. PSF images showed correction to 0.5″ FWHM. Uncorrected images showed the seeing to be about 1″. The images were deconvolved using several methods to check for consistency. We used Iterative-Blind Deconvolution, Richardson-Lucy, and Wiener filter algorithms, getting similar results for each. Measurements suggest the PSF in the deconvolved images is approximately 0.35″ FWHM.

scholarly journals High-resolution survey for planetary companions to young stars in the Taurus molecular cloud

2020 ◽  
Vol 498 (1) ◽  
pp. 1382-1396
Author(s):  
A L Wallace ◽  
J Kammerer ◽  
M J Ireland ◽  
C Federrath ◽  
A L Kraus ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Semimajor Axis ◽  
Infrared Camera ◽  
Single Class ◽  
Hot Start ◽  
Guide Star ◽  
Laser Guide ◽  
Large Telescopes ◽  
Differential Imaging

ABSTRACT Direct imaging in the infrared at the diffraction limit of large telescopes is a unique probe of the properties of young planetary systems. We survey 55 single class I and class II stars in Taurus in the L’ filter using natural and laser guide star adaptive optics and the near-infrared camera (NIRC2) of the Keck II telescope, in order to search for planetary-mass companions. We use both reference star differential imaging and kernel phase techniques, achieving typical 5σ contrasts of ∼6 mag at separations of 0.2 arcsec and ∼8 mag beyond 0.5 arcsec. Although, we do not detect any new faint companions, we constrain the frequency of wide separation massive planets, such as HR 8799 analogues. We find that, assuming hot-start models and a planet distribution with power-law mass and semimajor axis indices of −0.5 and −1, respectively, less than 20 per cent of our target stars host planets with masses >2 MJ at separations >10 au.

scholarly journals Candidate Population III stellar complex at z = 6.629 in the MUSE Deep Lensed Field

2020 ◽  
Vol 494 (1) ◽  
pp. L81-L85 ◽  
Author(s):  
E Vanzella ◽  
M Meneghetti ◽  
G B Caminha ◽  
M Castellano ◽  
F Calura ◽  
...  
Keyword(s):  
Rest Frame ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
Galaxy Cluster ◽  
Space Telescope ◽  
James Webb Space Telescope ◽  
H Ii Region ◽  
Large Telescopes ◽  
The Continuum ◽  
Population Iii

ABSTRACT We discovered a strongly lensed (μ ≳ 40) Ly α emission at z = 6.629 (S/N ≃ 18) in the MUSE Deep Lensed Field (MDLF) targeting the Hubble Frontier Field (HFF) galaxy cluster MACS J0416. Dedicated lensing simulations imply that the Ly α emitting region necessarily crosses the caustic. The arc-like shape of the Ly α extends 3 arcsec on the observed plane and is the result of two merged multiple images, each one with a de-lensed Ly α luminosity L ≲ 2.8 × 1040 erg s−1 arising from a confined region (≲150 pc effective radius). A spatially unresolved Hubble Space Telescope(HST) counterpart is barely detected at S/N ≃ 2 after stacking the near-infrared bands, corresponding to an observed (intrinsic) magnitude m1500 ≳ 30.8 (≳35.0). The inferred rest-frame Ly α equivalent width is EW0 > 1120 Å if the IGM transmission is TIGM < 0.5. The low luminosities and the extremely large Ly α EW0 match the case of a Population III (Pop III) star complex made of several dozens stars (∼104 M⊙) that irradiate an H ii region crossing the caustic. While the Ly α and stellar continuum are among the faintest ever observed at this redshift, the continuum and the Ly α emissions could be affected by differential magnification, possibly biasing the EW0 estimate. The aforementioned tentative HST detection tends to favour a large EW0, making such a faint Pop III candidate a key target for the James Webb Space Telescope and Extremely Large Telescopes.

scholarly journals Panchromatic imaging and modeling of SSTtau J042021+281349: A new prototypical edge-on protoplanetary disk

2013 ◽  
Vol 8 (S299) ◽  
pp. 111-112
Author(s):  
G. Duchêne ◽  
K. Stapelfeldt ◽  
A. Isella ◽  
M. Perrin ◽  
F. Ménard ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
Scattered Light ◽  
Protoplanetary Disk ◽  
Advanced Stage ◽  
High Degree ◽  
Dust Evolution ◽  
Adaptive Optics System ◽  
New System

AbstractWe present new high-resolution observations and modeling of SSTtau J042021+ 281349, a 400 AU-radius edge-on protoplanetary disk. We have gathered visible and near-infrared scattered light images of the system with the Hubble Space Telescope and Keck adaptive optics system, as well as a 1.3 mm continuum map with CARMA. Compared to the well-known HH 30 disk, this new system is remarkable because of its spectacular bipolar jet and the high degree of lateral symmetry of the disk. Indeed, we argue that this system is a “cleaner” prototype for edge-on disks. In addition, the apparent achromaticity of dust properties (most notably the almost grey opacity law) from the visible to the near-infrared in this disk suggests that it is in an advanced stage of dust evolution.

scholarly journals Optical and Near-Infrared Imaging of Young Binary Star Environments

2001 ◽  
Vol 200 ◽  
pp. 234-244
Author(s):  
François Ménard ◽  
Karl Stapelfeldt
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Hubble Space Telescope ◽  
Binary Star ◽  
Circumstellar Matter ◽  
Prototype System ◽  
Multiple Star ◽  
Near Ir ◽  
Imaging Results

We review recent imaging results on the circumstellar matter of young binaries obtained using the Hubble Space Telescope (HST) and by PUEO, a ground-based adaptive optics (AO) system operating at CFHT. In the area of circumbinary disks, new results for GG Tau help form a more complete picture of this prototype system. However, HST images of the UY Aur ring indicate a more complex system than first thought. A new example of a circumstellar disk in a multiple star system has been found in HV Tau, joining HK Tau in this category. Examples of envelopes, outflow cavities, and jets are shown for several young binaries. About half of the nearby young binaries in our survey possess some kind of local nebulosity at optical or near-IR wavelengths.

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