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Related papers: On the temporal evolution of spicules observed wit…

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We present the first results of a high-spectral-resolution survey of the carbon-rich evolved star IRC+10216 that was carried out with the HIFI spectrometer onboard Herschel. This survey covers all HIFI bands, with a spectral range from 488…

Solar jets are impulsive, collimated plasma ejections that are triggered by magnetic reconnection. They are observed for many decades in various temperatures and wavelengths, therefore their kinematic characteristics, such as velocity and…

Solar and Stellar Astrophysics · Physics 2022-08-17 Brigitte Schmieder , Reetika Joshi , Ramesh Chandra

We report on the properties of coronal loop foot-point heating with observations at the highest resolution, from the CRisp Imaging Spectro-Polarimeter (CRISP) located at the Swedish 1-m Solar Telescope (SST) and co-aligned NASA Solar…

Solar and Stellar Astrophysics · Physics 2021-11-24 V. N. Nived , E. Scullion , J. G. Doyle , R. Susino , P. Antolin , D. Spadaro , C. Sasso , S. Sahin , M. Mathioudakis

We present Herschel-HIFI, SPIRE, and PACS 50-670 {\mu}m imaging and spectroscopy of six FU Orionis-type objects and candidates (FU Orionis, V1735 Cyg, V1515 Cyg, V1057 Cyg, V1331 Cyg, and HBC 722), ranging in outburst date from 1936-2010,…

Using K2, we recently discovered a new type of periodic photometric variability while analysing the light curves of members of Upper Sco (Stauffer \etal\ 2017). The 23 exemplars of this new variability type are all mid-M dwarfs, with short…

Solar and Stellar Astrophysics · Physics 2021-01-20 J. R. Stauffer , L. M. Rebull , M. Jardine , A. Collier Cameron , A. M. Cody , L. A. Hillenbrand , D. Barrado , E. Kruse , B. P. Powell

We have systematically investigated ultraviolet (UV) emission from molecular hydrogen (H$_{2}$) using the Interface Region Imaging Spectrometer (IRIS), during three X-ray flares of C5.1, C9.7 and X1.0 classes on Oct. 25, 2014. Significant…

Solar and Stellar Astrophysics · Physics 2023-09-15 Sargam M. Mulay , Lyndsay Fletcher , Hugh Hudson , Nicolas Labrosse

Spicules are plasma jets, observed in the dynamic interface region between the visible solar surface and the hot corona. At any given time, it is estimated that about 3 million spicules are present on the Sun. We find an intriguing parallel…

Solar and Stellar Astrophysics · Physics 2022-11-10 Sahel Dey , Piyali Chatterjee , Murthy O. V. S. N. , Marianna B. Korsos , Jiajia Liu , Christopher J. Nelson , Robertus Erdelyi

Featureless optical and ultraviolet (UV) spectra are a puzzling signature to emerge from recent observations of luminous fast blue optical transients (LFBOTs) and some tidal disruption events (TDEs). We describe the landscape of source and…

High Energy Astrophysical Phenomena · Physics 2026-04-21 Olivia Aspegren , Daniel Kasen

In this third paper in a series we compare spectral feature measurements to photometric properties of 108 low-redshift (z < 0.1) Type Ia supernovae (SNe Ia) with optical spectra within 5 d of maximum brightness. We find the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jeffrey M. Silverman , Mohan Ganeshalingam , Weidong Li , Alexei V. Filippenko

It is well-known that extreme ultraviolet emission emitted at the solar surface is absorbed by overlying cool plasma. Especially in active regions dark lanes in EUV images suggest that much of the surface activity is obscured. Simultaneous…

Solar and Stellar Astrophysics · Physics 2016-12-14 N. -H. Chen , D. E. Innes

Solar jets are an important field of study, as they may contribute to the mass and energy transfer from the lower to the upper atmosphere. We use the Interface Region Imaging Spectrograph (IRIS) and Solar Dynamic Observatory (SDO)…

Solar and Stellar Astrophysics · Physics 2024-10-01 Myrto Koletti , Costis Gontikakis , Spiros Patsourakos , Kanaris Tsinganos

We study the polarization signals and physical parameters of penumbral microjets (PMJs) by using high spatial resolution data taken in the Fe I 630 nm pair, Ca II 854.2 nm and Ca II K lines with the CRISP and CHROMIS instruments at the…

Solar and Stellar Astrophysics · Physics 2019-01-16 S. Esteban Pozuelo , J. de la Cruz Rodriguez , A. Drews , L. Rouppe van der Voort , G. B. Scharmer , M. Carlsson

Type II supernovae (SNe II) show strong hydrogen features in their spectra throughout their whole evolution while type IIb supernovae (SNe IIb) spectra evolve from dominant hydrogen lines at early times to increasingly strong helium…

We report on spectro-imaging observations employing Spitzer IRS and Herschel PACS, aiming to constrain the physical conditions around SMM3 and SMM4 in Serpens. The combined power of both instruments provides an almost complete wavelength…

We present a statistical algorithm for predicting the [CII] emission from Herschel and Spitzer continuum images using probability density functions between the [CII] emission and continuum emission. The [CII] emission at 158 $\mu$m is a…

Astrophysics of Galaxies · Physics 2023-08-23 Young Min Seo , Karen Willacy , Umaa Rebbapragada

Context: Except for the Ca II resonance lines, fibrils are ubiquitously present in most high-resolution observations of chromospheric lines. Aims: We show that fibrils are also a prevailing feature in Ca II K, provided the…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. Pietarila , J. Hirzberger , V. Zakharov , S. K. Solanki

We present an overview of fine-scale features in the Sun's atmosphere, with a focus on spicules and jets. We consider older and newer observations and theories for chromospheric spicules and coronal jets. We also consider the connection…

Solar and Stellar Astrophysics · Physics 2025-12-04 Alphonse C. Sterling

Speckle is the spatial fluctuation of irradiance seen when coherent light is reflected from a rough surface. It is due to light reflected from the surface's many nooks and crannies accumulating vastly-discrepant time delays, spanning much…

Optics · Physics 2020-08-26 Justin Dove , Jeffrey H. Shapiro

We examine the possibility of evolution with redshift in the mean rest-frame ultraviolet (UV; <4500A) spectrum of Type Ia Supernovae (SNe Ia) sampling the redshift range 0<z<1.3. We find new evidence for a decrease with redshift in the…

Solar and Stellar Astrophysics · Physics 2011-02-11 M. Sullivan , R. S. Ellis , D. A. Howell , A. Riess , P. E. Nugent , A. Gal-Yam

The time domain remains, in many respects, the least explored of parameter spaces in astronomical studies. The purpose of this article is to encourage the SPICA community to consider the potential of rapid infrared timing observations. The…

High Energy Astrophysical Phenomena · Physics 2013-10-15 P. Gandhi , D. M. Russell , P. Casella , J. Malzac , T. Nakagawa