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The 04 – 10 September 2017 Sun–Earth Connection Events: Solar Flares, Coronal Mass Ejections/Magnetic Clouds, and Geomagnetic Storms
(Springer Netherlands, 2019-08-23) Wu, Chin-Chun; Liou, Kan; Lepping, Ronald P.; Hutting, Lynn
In early September 2017, a series of solar flares and coronal mass ejections (CMEs) erupted from the Sun. The Cor2a coronagraph, a unit of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI), onboard the Solar Terrestrial Relations Observatory (STEREO)-A spacecraft recorded two Sun–Earth-directed CMEs on 4 September (referred to as CME04) and 6 September (referred to as CME06). A few days later, the Wind spacecraft ( ≈212.4 solar radii: R⊙ ) recorded two interplanetary shocks, presumably driven by CME04 and CME06, at ≈22:41 UT on 06 September 2017 (referred to as Shock06) and at ≈22:48 UT on 07 September 2017 (referred to as Shock07), respectively. The travel time of the CME04/Shock06 [ Δtshock-CME@18R⊙ ] and CME06/Shock07 from 18 R⊙ to the Wind spacecraft was 41.52 hours and 32.47 hours, respectively. The propagating speed [ VCME ] of the CME04 and CME06 at ≈18 R⊙ was determined with SECCHI/Cor2a as ≈886 kms−1 and ≈1368 kms−1 , respectively. Assuming a constant velocity after 18 R⊙ , the estimated Δtshock-CME@18R⊙ is 42.45 and 27.5 hours for CME04 and CME06, respectively. This simple estimate of the CME propagation speed provides a satisfactory result for the CME04 event (error ≈2.3% ) but not for the CME06 event (error ≈15.3% ). The second event, CME06, was delayed further due to an interaction with the preceding event (CME04). It is suggested that the CME speed estimated near the Sun with coronagraph images can be a good estimator for the interplanetary CME (ICME) transit time when there is no pre-event. A three-dimensional magnetohydrodynamic simulation is performed to address this issue by providing a panoramic view of the entire process not available from the observations. A southward interplanetary magnetic field [ Bs ] increased sharply to −31.6 nT on 7 September at Wind, followed by a severe geomagnetic storm ( Dst=−124 nT ). The sharp increase of the IMF [ Bs ] was a result of the interaction between Shock07 and the driver of Shock06 (CME04). This study suggests that a severe geomagnetic storm can be caused by the interaction between a MC, with an impinging IP shock from behind, and the Earth’s magnetosphere. The intensity of a geomagnetic storm will likely be stronger for an event associated with ICME–ICME interaction than for a geomagnetic event caused by only a single ICME.
A 0535+26 in the August/September 2005 outburst observed by RXTE and INTEGRAL
(EDP Sciences, 2007-02-20) Caballero, I.; Kretschmar, P.; Santangelo, A.; Staubert, R.; Klochkov, D.; Camero, A.; Ferrigno, C.; Finger, M. H.; Kreykenbohm, I.; McBride, V. A.; Pottschmidt, Katja; Rothschild, R. E.; Schönherr, G.; Segreto, A.; Suchy, S.; Wilms, J.; Wilson, C. A.
Aims. In this Letter we present results from INTEGRAL and RXTE observations of the spectral and timing behavior of the High Mass X-ray Binary A 0535+26 during its August/September 2005 normal (type I) outburst with an average flux F₍₅₋₁₀₀₎ ₖₑᵥ ~ 400 mCrab. The search for cyclotron resonance scattering features (fundamental and harmonic) is one major focus of the paper. Methods. Our analysis is based on data from INTEGRAL and RXTE Target of Opportunity Observations performed during the outburst. The pulse period is determined. X-ray pulse profiles in different energy ranges are analyzed. The broad band INTEGRAL and RXTE pulse phase averaged X-ray spectra are studied. The evolution of the fundamental cyclotron line at different luminosities is analyzed. Results.The pulse period P is measured to be 103.39315(5) s at MJD 53614.5137. Two absorption features are detected in the phase averaged spectra at E₁ ~ 45 keV and E₂ ~ 100 keV. These can be interpreted as the fundamental cyclotron resonance scattering feature and its first harmonic and therefore the magnetic field can be estimated to be B ~4 × 10¹² G.
0FGL J1830.3+0617: A FERMI BLAZAR NEAR THE GALACTIC PLANE
(IOP, 2009-08-10) Mirabal, N.; Halpern, J. P.
aas-2018.png iop-2016.png 0FGL J1830.3+0617: A FERMI BLAZAR NEAR THE GALACTIC PLANE N. Mirabal1,3 and J. P. Halpern2 Published 10 August 2009 • © 2009. The American Astronomical Society. All rights reserved. The Astrophysical Journal Letters, Volume 701, Number 2 DownloadArticle PDF Figures References 642 Total downloads 1818 total citations on Dimensions. Turn on MathJax Get permission to re-use this article Share this article Share this content via email Share on Facebook Share on Twitter Share on Google+ Share on Mendeley Article information Abstract We present a multiwavelength study of the unidentified Fermi γ-ray source 0FGL J1830.3+0617, which exhibits variability above 200 MeV on timescales of days to weeks. Within the Fermi 95% confidence error contour lies B1827+0617, a radio source with spectral index α = 0.09 between 1.4 and 4.85 GHz. The flat spectral index and flux density of 443 mJy at 4.85 GHz are consistent with the bulk of Fermi sources associated with blazars. It is also detected in the 0.3-10 keV band by Swift. Optical imaging in 2009 May identifies B1827+0617 at R ≈ 16.9, and shows that it is at least 2 mag brighter than on the Palomar Sky Survey plates. Contemporaneous optical spectroscopy acquired during this high state finds a weak emission line that we attribute to Mg II λ2798 at redshift z = 0.75, supporting a flat spectrum radio quasar classification. The variability characteristics and radio properties together indicate that 0FGL J1830.3+0617 at Galactic latitude b = +7.5 is a blazar. Blazar identifications of three additional low-latitude Fermi sources, 0FGL J0643.2+0858, 0FGL J1326.6 – 5302, and 0FGL J1328.8 – 5604, are also suggested.
10 Admissions Deans Who Are Shaping Their Field
(The Chronicle of Higher Education, 2007-04-27) Farrell, Elizabeth F.; Hoover, Eric
A 100-Gb/s noncoherent silicon receiver for PDM-DBPSK/DQPSK signals
(Optica, 2014) Klamkin, Jonathan; Gambini, Fabrizio; Faralli, Stefano; Malacarne, Antonio; Meloni, Gianluca; Berrettini, Gianluca; Contestabile, Giampiero; Potì, Luca
An integrated noncoherent silicon receiver for demodulation of 100-Gb/s polarization-division multiplexed differential quadrature phaseshift keying and polarization-division multiplexed differential binary phaseshift keying signals is demonstrated. The receiver consists of a 2D surface grating coupler, four Mach-Zehnder delay interferometers and four germanium balanced photodetectors.
150 years of the geography of innovation
(Elsevier, 2021-01-25) Andrews, Michael J.; Whalley, Alexander
Innovation has long been seen as central to long-term regional growth. Due to the absence of comprehensive data on the geography of innovation covering long time periods, quantifying long-term innovation-development linkages has been challenging. We use newly available patent data from the United States coded to consistent geographies over 150 years to document changing patterns in the geography of innovation. Our analysis reveals three findings. First, the high levels of spatial concentration of innovation today are similar to those in the decades after the Civil War. Second, changes in share of the top 1% locations’ innovation drive national spatial concentration trends after 1945. Third, regional innovation leadership displays persistence, but the strength of persistence appears to have fallen over time. We relate our analysis recent findings in the literature and suggest promising avenues for future inquiry.
A 1652 treaty opens up the story of the first “Baltimoreans”
(Baltimore Brew, 2019-12-10) Shen, Fern
The 17 April 2021 widespread solar energetic particle event
(2023-03-20) Dresing, N.; Rodríguez-García, L.; Jebaraj, I. C.; Warmuth, A.; Krupar, Vratislav; Silva, Daniel da; et al
Context. A complex and long-lasting solar eruption on 17 April 2021 produced a widespread Solar Energetic Particle (SEP) event that was observed by five longitudinally well-separated observers in the inner heliosphere covering distances to the Sun from 0.42 to 1 au: BepiColombo, Parker Solar Probe, Solar Orbiter, STEREO A, and near-Earth spacecraft. The event was the second widespread SEP event dected in solar cycle 25 and produced relativistic electrons and protons. It was associated with a long-lasting solar hard X-ray flare showing multiple hard X-ray peaks over a duration of one hour. The event was further accompanied by a medium fast Coronal Mass Ejection (CME) with a speed of 880 km s−1 driving a shock, an EUV wave as well as long-lasting and complex radio burst activity showing four distinct type III burst groups over a period of 40 minutes. Aims. We aim at understanding the reason for the the wide spread of elevated SEP intensities in the inner heliosphere as well as identifying the underlying source regions of the observed energetic electrons and protons. Methods. A comprehensive multi-spacecraft analysis of remote-sensing observations and in-situ measurements of the energetic particles and interplanetary context is applied to attribute the SEP observations at the different locations to the various potential source regions at the Sun. An ENLIL simulation is used to characterize the complex interplanetary state and its role for the energetic particle transport. The magnetic connection between each spacecraft and the Sun is determined using ballistic backmapping in combination with potential field source surface extrapolations in the lower corona. In combination with a reconstruction of the coronal shock front we then determine the times when the shock establishes magnetic connections with the different observers. Radio observations are used to characterize the directivity of the four main injection episodes, which are then employed in a 2D SEP transport simulation to test the importance of these different injection episodes. Results. A comprehensive timing analysis of the inferred solar injection times of the SEPs observed at each spacecraft suggests different source processes being important for the electron and the proton event. Comparison among the characteristics and timing of the potential particle sources, such as the CME-driven shock or the flare, suggests a stronger shock contribution for the proton event and a more likely flare-related source of the electron event. Conclusions. In contrast to earlier studies on widespread SEP events, we find that in this event an important ingredient for the wide SEP spread was the wide longitudinal range of about 110◦ covered by distinct SEP injections, which is also supported by our SEP transport modeling.
17β-Estradiol (E2) may be involved in the mode of crustacean female sex hormone (CFSH) action in the blue crab, Callinectes sapidus
(Frontiers, 2022-07-25) Wang, Tao; He, Ke; Blaney, Lee; Chung, J. Sook
17β-estradiol (E2) has been proved to control reproduction, sexual differentiation, and the development of the secondary sexual characteristics of vertebrate females. In decapod crustacean species, crustacean female sex hormone (CFSH), a protein hormone, is required for developing adult-specific ovigerous setae for embryo brooding and gonophores for mating at the blue crab Callinectes sapidus puberty molting. However, it is unclear that whether the mode of CFSH action involves a vertebrate-type sex steroid hormone in crustaceans. To this end, E2 levels were first measured using a competitive ELISA in the hemolymph and the potential CFSH target tissues from both prepuberty and adult females; the presence of E2 was further confirmed with a liquid chromatography tandem mass spectrometry method. Then, the cDNAs of the following genes known to be associated with vertebrate steroidogenic pathways were isolated: StAR-related lipid transfer protein 3 (StAR3); 3β-hydroxysteroid dehydrogenase (3βHSD); two isoforms of 17β-hydroxysteroid dehydrogenase 8 (17βHSD8); and, estradiol-related receptor (ERR). RT-PCR analysis revealed that these genes were widely distributed in the eyestalk ganglia, hepatopancreas, brain, ovary, spermathecae, ovigerous and plumose setae tissues of adult females. The 17βHSD8 transcripts were localized in the follicle cells, the periphery of the nuclear membrane of primary oocytes, and yolk granules of the vitellogenic oocytes using in situ hybridization, and the corresponding protein was detected in the follicle cells and ooplasm of primary oocytes using immunohistochemistry. Furthermore, the adult females injected with CFSH-dsRNA (n = 30 times) had E2 and StAR3 transcripts levels lower in the ovigerous and plumose setae, spermathecae than controls. These results suggested that the mode of CFSH action in C. sapidus might involve E2 in these adult-female-specific tissues.
A 1D fluid model of the Centaurus A jet
(2018-09-27) Wykes, Sarka; Snios, Bradford T.; Nulsen, Paul E. J.; Kraft, Ralph P.; Birkinshaw, Mark; Hardcastle, Martin J.; Worrall, Diana M.; McDonald, Iain; Rejkuba, Marina; Jones, Thomas W.; Stark, David J.; Forman, William R.; Meyer, Eileen T.; Jones, Christine
We implement a steady, one-dimensional flow model for the X-ray jet of Centaurus A in which entrainment of stellar mass loss is the primary cause of dissipation. Using over 260 ks of new and archival Chandra/ACIS data, we have constrained the temperature, density and pressure distributions of gas in the central regions of the host galaxy of Centaurus A, and so the pressure throughout the length of its jet. The model is constrained by the observed profiles of pressure and jet width, and conserves matter and energy, enabling us to estimate jet velocities, and hence all the other flow properties. Invoking realistic stellar populations within the jet, we find that the increase in its momentum flux exceeds the net pressure force on the jet unless only about one half of the total stellar mass loss is entrained. For self-consistent models, the bulk speed only falls modestly, from ~0.67c to ~0.52c over the range of 0.25-5.94 kpc from the nucleus. The sonic Mach number varies between ~5.3 and 3.6 over this range.
1E 1740.7-2942 (the Great Annihilator) enters a low-intensity state
(The Astronomer's Telegram, 2012-10-09) Kuulkers, E.; Ferrigno, C.; Santo, M. Del; Bazzano, A.; Alfonso-Garzon, J.; Beckmann, V.; Bird, A. J.; Brandt, S.; Chenevez, J.; Courvoisier, T. J.-L.; Domingo, A.; Ebisawa, K.; Jonker, P. G.; Kretschmar, P.; Markwardt, C. B.; Oosterbroek, T.; Paizis, A.; Pottschmidt, Katja; Sanchez-Fernandez, C.; Wijnands, R.
2 mm GISMO Observations of the Galactic Center. I. Dust Emission
(The American Astronomical Society, 2019-11-01) Arendt, Richard G; Staguhn, Johannes; Dwek, Eli; Morris, Mark R; Yusef-Zadeh, Farhad; Benford, Dominic J; Kovacs, Attila; Gonzalez-Quiles, Junellie
The Central Molecular Zone (CMZ), covering the inner ∼ 1 ◦ of the Galactic plane has been mapped at 2 mm using the GISMO bolometric camera on the 30 m IRAM telescope. The 2100 resolution maps show abundant emission from cold molecular clouds, from star forming regions, and from one of the Galactic center nonthermal filaments. In this work we use the Herschel Hi-GAL data to model the dust emission across the Galactic center. We find that a single-temperature fit can describe the 160 – 500 µm emission for most lines of sight, if the long-wavelength dust emissivity scales as λ −β with β ≈ 2.25. This dust model is extrapolated to predict the 2 mm dust emission. Subtraction of the model from the GISMO data provides a clearer look at the 2 mm emission of star-forming regions and the brightest nonthermal filament.
2 mm GISMO Observations of the Galactic Center. II. A Nonthermal Filament in the Radio Arc and Compact Sources
(The American Astronomical Society, 2019-11-01) Staguhn, Johannes; Arendt, Richard G; Dwek, Eli; Morris, Mark R; Yusef-Zadeh, Farhad; Benford, Dominic J; Kovacs, Attila; Gonzalez-Quiles, Junellie
We have used the Goddard IRAM 2-Millimeter Observer (GISMO) with the 30 m IRAM telescope to carry out a 2 mm survey of the Galaxy’s central molecular zone (CMZ). These observations detect thermal emission from cold ISM dust, thermal free-free emission from ionized gas, and nonthermal synchrotron emission from relatively flat-spectrum sources. Archival data sets spanning 3.6 µm to 90 cm are used to distinguish different emission mechanisms. After the thermal emission of dust is modeled and subtracted, the remaining 2 mm emission is dominated by free-free emission, with the exception of the brightest nonthermal filament (NTF) that runs though the middle of the bundle of filaments known as the Radio Arc. This is the shortest wavelength at which any NTF has been detected. The GISMO observations clearly trace this NTF over a length of ∼ 0.2 ◦ , with a mean 2 mm spectral index which is steeper than at longer wavelengths. The 2 mm to 6 cm (or 20 cm) spectral index steepens from α ≈ −0.2 to −0.7 as a function distance from the Sickle H II region, suggesting that this region is directly related to the NTF. A number of unresolved (at 21′′) 2 mm sources are found nearby. One appears to be thermal dust emission from a molecular cloud that is associated with an enigmatic radio point source whose connection to the Radio Arc is still debated. The morphology and colors at shorter IR wavelengths indicate other 2 mm unresolved sources are likely to be compact H II regions.
20 years of change in tundra NDVI from coupled field and satellite observations
(IOP Publishing, 2023-08-17) Huemmrich, Karl; Gamon, John; Campbell, Petya Entcheva; Mora, Marianna; Vargas Z, Sergio; Almanza, Brenda; Tweedie, Craig
In 2022 we resampled normalized difference vegetation index (NDVI) along a 100 m transect in tundra near Utqiagvik, AK that had been previously measured through the 2000–2002 growing seasons, providing an opportunity to examine a 20 year NDVI change at a 1 m resolution in a region that is experiencing increased warming and precipitation over this period. Multidecadal NDVI change was spatially variable across the transect with nearly half of the transect showing greening, about a third not showing conclusive change, and about 20% browning. In wet areas, greening (increased NDVI) was associated with increased green leaf area index, while in drier areas greening was related to changes in species cover. Browning was not related to change in species cover and appeared to be due to increased coverage of standing dead material in graminoid dominated canopies. These types of detailed observations provide insights into the interpretation of satellite based NDVI trends and emphasize the importance of microtopography and hydrology in mediating vegetation change in a warming Arctic.
The 2001 Superoutburst of WZ Sagittae
(IOP, 2002-06-10) Patterson, Joseph; Masi, Gianluca; Richmond, Michael W.; Martin, Brian; Beshore, Edward; Skillman, David R.; Kemp, Jonathan; Vanmunster, Tonny; Rea, Robert; Allen, William; Davis, Stacey; Davis, Tracy; Henden, Arne A.; Starkey, Donn; Foote, Jerry; Oksanen, Arto; Cook, Lewis M.; Fried, Robert E.; Husar, Dieter; Novák, Rudolf; Campbell, Tut; Robertson, Jeff; Krajci, Thomas; Pavlenko, Elena; Mirabal, Nestor; Niarchos, Panos G.; Brettman, Orville; Walker, Stan
We report the results of a worldwide campaign to observe WZ Sagittae during its 2001 superoutburst. After a 23 yr slumber at V = 15.5, the star rose within 2 days to a peak brightness of 8.2, and showed a main eruption lasting 25 days. The return to quiescence was punctuated by 12 small eruptions, of ~1 mag amplitude and 2 day recurrence time; these "echo outbursts" are of uncertain origin, but somewhat resemble the normal outbursts of dwarf novae. After 52 days, the star began a slow decline to quiescence. Periodic waves in the light curve closely followed the pattern seen in the 1978 superoutburst: a strong orbital signal dominated the first 12 days, followed by a powerful common superhump at 0.05721(5) day, 0.92(8)% longer than Porb. The latter endured for at least 90 days, although probably mutating into a "late" superhump with a slightly longer mean period [0.05736(5) day]. The superhump appeared to follow familiar rules for such phenomena in dwarf novae, with components given by linear combinations of two basic frequencies: the orbital frequency ωo and an unseen low frequency Ω, believed to represent the accretion disk's apsidal precession. Long time series reveal an intricate fine structure, with ~20 incommensurate frequencies. Essentially all components occurred at a frequency nωo - mΩ, with m = 1, ..., n. But during its first week, the common superhump showed primary components at nωo - Ω, for n = 1, 2, 3, 4, 5, 6, 7, 8, 9 (i.e., m = 1 consistently); a month later, the dominant power shifted to components with m = n - 1. This may arise from a shift in the disk's spiral‐arm pattern, likely to be the underlying cause of superhumps. The great majority of frequency components are redshifted from the harmonics of ωo, consistent with the hypothesis of apsidal advance (prograde precession). But a component at 35.42 cycles day⁻¹ suggests the possibility of a retrograde precession at a different rate, probably N = 0.13 ± 0.02 cycles day⁻¹. The eclipses permit measuring the location and brightness of the mass‐transfer hot spot. The disk must be very eccentric and nearly as large as the white dwarf's Roche lobe. The hot‐spot luminosity exceeds its quiescent value by a factor of up to 60. This indicates that enhanced mass transfer from the secondary plays a major role in the eruption.
THE 2010 MAY FLARING EPISODE OF CYGNUS X-3 IN RADIO, X-RAYS, AND γ-RAYS
(IOP Publishing, 2011-05-05) Williams, Peter K. G.; Tomsick, John A.; Bodaghee, Arash; Bower, Geoffrey C.; Pooley, Guy G.; Pottschmidt, Katja; Rodriguez, Jérôme; Wilms, Jörn; Migliari, Simone; Trushkin, Sergei A.
In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and γ-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ∼3 day softening and recovery of the X-ray emission, followed almost immediately by a ∼1 Jy radio flare at 15 GHz, followed by a 4.3σ γ-ray flare (E > 100 MeV) ∼1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the γ-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the γ-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for γ-ray emission from Cyg X-3.
2012 Laird Fellow
(University of Delaware, 2012-06-01)
The prestigious fellowship honors the memory of George W. Laird, a UD mechanical engineering graduate who died in an accident at the age of 35. Given since 1997, it is bestowed upon candidates who exhibit character, creativity, imagination and perseverance, all of which are focal points of the selection process.
The 2013 FLEX—US Airborne Campaign at the Parker Tract Loblolly Pine Plantation in North Carolina, USA
(MDPI, 2017-06-16) Middleton, Elizabeth M.; Rascher, Uwe; Corp, Lawrence A.; Huemmrich, Karl; Cook, Bruce D.; Noormets, Asko; Schickling, Anke; Pinto, Francisco; Alonso, Luis; Damm, Alexander; Guanter, Luis; Colombo, Roberto; Campbell, Petya Entcheva; Landis, David R.; Zhang, Qingyuan; Rossini, Micol; Schuettemeyer, Dirk; Bianchi, Remo
The first European Space Agency (ESA) and NASA collaboration in an airborne campaign to support ESA’s FLuorescence EXplorer (FLEX) mission was conducted in North Carolina, USA during September–October 2013 (FLEX-US 2013) at the Parker Tract Loblolly Pine (LP) Plantation (Plymouth, NC, USA). This campaign combined two unique airborne instrument packages to obtain simultaneous observations of solar-induced fluorescence (SIF), LiDAR-based canopy structural information, visible through shortwave infrared (VSWIR) reflectance spectra, and surface temperature, to advance vegetation studies of carbon cycle dynamics and ecosystem health. We obtained statistically significant results for fluorescence, canopy temperature, and tower fluxes from data collected at four times of day over two consecutive autumn days across an age class chronosequence. Both the red fluorescence (F685) and far-red fluorescence (F740) radiances had highest values at mid-day, but their fluorescence yields exhibited different diurnal responses across LP age classes. The diurnal trends for F685 varied with forest canopy temperature difference (canopy minus air), having a stronger daily amplitude change for young vs. old canopies. The Photochemical Reflectance Index (PRI) was positively correlated with this temperature variable over the diurnal cycle. Tower measurements from mature loblolly stand showed the red/far-red fluorescence ratio was linearly related to canopy light use efficiency (LUE) over the diurnal cycle, but performed even better for the combined morning/afternoon (without midday) observations. This study demonstrates the importance of diurnal observations for interpretation of fluorescence dynamics, the need for red fluorescence to understand canopy physiological processes, and the benefits of combining fluorescence, reflectance, and structure information to clarify canopy function versus structure characteristics for a coniferous forest.
2019 Forest Service–NASA Joint Applications Workshop: Satellite Data to Support Natural Resource Management: A Framework for Aligning NASA Products with Land Management Agency Needs
(U.S. Department of Agriculture, 2023-09) Reeves, Matthew C.; Stavros, E. Natasha; Glenn, Nancy F.; Hudak, Andy; Peterson, Birgit; Armstrong, Amanda; Hinkley, Everett; Hoy, Elizabeth; Atkins, Jeff W.
In 2019, approximately 103 participants from the U.S. Department of Agriculture, Forest Service (Forest Service), NASA (including representatives from SMAP, NISAR, ICESat-2, GEDI, CMS), and other federal, private and academic entities attended the USFS-NASA Joint Applications Workshop. The objective of this workshop was to increase awareness and understanding of the capabilities of NASA data products, as well as to develop connections and strengthen partnerships between NASA and the Forest Service. In this vein the workshop sought to identify opportunities for collaboration between the Forest Service and NASA on the topics of (1) soil moisture and hydrology, (2) carbon emissions and flux, and (3) vegetation structure and function. During breakout sessions participants discussed key opportunities and challenges of utilizing NASA technology by land management agencies. The list below represents key high-level opportunities for increased USFS-NASA coordination and collaboration to support sustainable natural resource management.
The 2019 outburst of the 2005 classical nova V1047 Cen: a record breaking dwarf nova outburst or a new phenomenon?
(2021-08-17) Aydi, E.; Sokolovsky, K. V.; Bright, J. S.; Tremou, E.; Nyamai, M. M.; Evans, A.; Strader, J.; Chomiuk, L.; Myers, G.; Hambsch, F-J.; Page, K. L.; Buckley, D. A. H.; Woodward, C. E.; Walter, F. M.; Mróz, P.; Vallely, P. J.; Geballe, T. R.; Banerjee, D. P. K.; Gehrz, R. D.; Fender, R. P.; Gromadzki, M.; Kawash, A.; Knigge, C.; Mukai, K.; Munari, U.; Orio, M.; Ribeiro, V. A. R. M.; Sokoloski, J. L.; Starrfield, S.; Udalski, A.; Woudt, P. A.
We present a detailed study of the 2019 outburst of the cataclysmic variable V1047 Cen, which hosted a classical nova eruption in 2005. The peculiar outburst occurred 14 years after the classical nova event, lasted for more than 400 days, and reached an amplitude of around 6 magnitudes in the optical. Early spectral follow-up revealed what could be a dwarf nova (accretion disk instability) outburst in a classical nova system. However, the outburst duration, high velocity (>2000 km s⁻¹) features in the optical line profiles, luminous optical emission, and the presence of prominent long-lasting radio emission, together suggest a phenomenon more exotic and energetic than a dwarf nova outburst. There are striking similarities between this V1047 Cen outburst and those of "combination novae" in classical symbiotic stars. We suggest that the outburst may have started as a dwarf nova that led to the accretion of a massive disk, which in turn triggered enhanced nuclear shell burning on the white dwarf and eventually led to generation of a wind/outflow. From optical photometry we find a \bf{possible} orbital period of 8.36 days, which supports the combination nova scenario and makes the system an intermediate case between typical cataclysmic variables and classical symbiotic binaries. If true, such a phenomenon would be the first of its kind to occur in a system that has undergone a classical nova eruption and is intermediate between cataclysmic variables and symbiotic binaries.

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