Solanki, Sami K.

[["dc.bibliographiccitation.artnumber","L23"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","The Astrophysical Journal Letters"],["dc.bibliographiccitation.volume","934"],["dc.contributor.affiliation","Nèmec, N.-E.;"],["dc.contributor.affiliation","Shapiro, A. I.;"],["dc.contributor.affiliation","Işık, E.;"],["dc.contributor.affiliation","Sowmya, K.;"],["dc.contributor.affiliation","Solanki, S. K.;"],["dc.contributor.affiliation","Krivova, N. A.;"],["dc.contributor.affiliation","Cameron, R. H.;"],["dc.contributor.affiliation","Gizon, L.;"],["dc.contributor.author","Nèmec, N.-E."],["dc.contributor.author","Shapiro, A. I."],["dc.contributor.author","Işık, E."],["dc.contributor.author","Sowmya, K."],["dc.contributor.author","Solanki, S. K."],["dc.contributor.author","Krivova, N. A."],["dc.contributor.author","Cameron, R. H."],["dc.contributor.author","Gizon, L."],["dc.date.accessioned","2022-08-01T07:35:55Z"],["dc.date.available","2022-08-01T07:35:55Z"],["dc.date.issued","2022-07-28"],["dc.date.updated","2022-07-30T02:55:06Z"],["dc.description.abstract","Surfaces of the Sun and other cool stars are filled with magnetic fields, which are either seen as dark compact spots or more diffuse bright structures like faculae. Both hamper detection and characterization of exoplanets, affecting stellar brightness and spectra, as well as transmission spectra. However, the expected facular and spot signals in stellar data are quite different, for instance, they have distinct temporal and spectral profiles. Consequently, corrections of stellar data for magnetic activity can greatly benefit from the insight on whether the stellar signal is dominated by spots or faculae. Here, we utilize a surface flux transport model to show that more effective cancellation of diffuse magnetic flux associated with faculae leads to spot area coverages increasing faster with stellar magnetic activity than that by faculae. Our calculations explain the observed dependence between solar spot and facular area coverages and allow its extension to stars that are more active than the Sun. This extension enables anticipating the properties of stellar signal and its more reliable mitigation, leading to a more accurate characterization of exoplanets and their atmospheres."],["dc.description.sponsorship","A. I. Shapiro"],["dc.identifier.doi","10.3847/2041-8213/ac8155"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/112556"],["dc.language.iso","en"],["dc.relation.eissn","2041-8213"],["dc.relation.issn","2041-8205"],["dc.rights","CC BY 4.0"],["dc.rights.uri","http://creativecommons.org/licenses/by/4.0/"],["dc.title","Faculae Cancel out on the Surfaces of Active Suns"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","66"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","852"],["dc.contributor.author","Siu-Tapia, A. L."],["dc.contributor.author","Rempel, M."],["dc.contributor.author","Lagg, A."],["dc.contributor.author","Solanki, S. K."],["dc.date.accessioned","2020-12-10T18:47:34Z"],["dc.date.available","2020-12-10T18:47:34Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.3847/1538-4357/aaa007"],["dc.identifier.eissn","1538-4357"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/78808"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Evershed and Counter-Evershed Flows in Sunspot MHD Simulations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A4"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","596"],["dc.contributor.author","Franz, M."],["dc.contributor.author","Collados, M."],["dc.contributor.author","Bethge, C."],["dc.contributor.author","Schlichenmaier, R."],["dc.contributor.author","Borrero, J. M."],["dc.contributor.author","Schmidt, W."],["dc.contributor.author","Lagg, A."],["dc.contributor.author","Solanki, S. K."],["dc.contributor.author","Berkefeld, T."],["dc.contributor.author","Kiess, C."],["dc.contributor.author","Rezaei, R."],["dc.contributor.author","Schmidt, Christian D."],["dc.contributor.author","Sigwarth, M."],["dc.contributor.author","Soltau, D."],["dc.contributor.author","Volkmer, R."],["dc.contributor.author","Luhe, O. von der"],["dc.contributor.author","Waldmann, T."],["dc.contributor.author","Orozco, D."],["dc.contributor.author","Pastor Yabar, A."],["dc.contributor.author","Denker, C."],["dc.contributor.author","Balthasar, H."],["dc.contributor.author","Staude, J."],["dc.contributor.author","Hofmann, A."],["dc.contributor.author","Strassmeier, K."],["dc.contributor.author","Feller, A."],["dc.contributor.author","Nicklas, H."],["dc.contributor.author","Kneer, F."],["dc.contributor.author","Sobotka, M."],["dc.date.accessioned","2020-07-01T07:16:29Z"],["dc.date.available","2020-07-01T07:16:29Z"],["dc.date.issued","2016"],["dc.description.abstract","Context. A significant part of the penumbral magnetic field returns below the surface in the very deep photosphere. For lines in the visible, a large portion of this return field can only be detected indirectly by studying its imprints on strongly asymmetric and three-lobed Stokes V profiles. Infrared lines probe a narrow layer in the very deep photosphere, providing the possibility of directly measuring the orientation of magnetic fields close to the solar surface. Aims. We study the topology of the penumbral magnetic field in the lower photosphere, focusing on regions where it returns below the surface. Methods. We analyzed 71 spectropolarimetric datasets from Hinode and from the GREGOR infrared spectrograph. We inferred the quality and polarimetric accuracy of the infrared data after applying several reduction steps. Techniques of spectral inversion and forward synthesis were used to test the detection algorithm. We compared the morphology and the fractional penumbral area covered by reversed-polarity and three-lobed Stokes V profiles for sunspots at disk center. We determined the amount of reversed-polarity and three-lobed Stokes V profiles in visible and infrared data of sunspots at various heliocentric angles. From the results, we computed center-to-limb variation curves, which were interpreted in the context of existing penumbral models. Results. Observations in visible and near-infrared spectral lines yield a significant difference in the penumbral area covered by magnetic fields of opposite polarity. In the infrared, the number of reversed-polarity Stokes V profiles is smaller by a factor of two than in the visible. For three-lobed Stokes V profiles the numbers differ by up to an order of magnitude."],["dc.identifier.arxiv","1608.00513v2"],["dc.identifier.doi","10.1051/0004-6361/201628407"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/66810"],["dc.language.iso","en"],["dc.relation.eissn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.title","Magnetic fields of opposite polarity in sunspot penumbrae"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A17"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","653"],["dc.contributor.author","Saranathan, S."],["dc.contributor.author","van Noort, M."],["dc.contributor.author","Solanki, S. K."],["dc.date.accessioned","2021-10-01T09:57:47Z"],["dc.date.available","2021-10-01T09:57:47Z"],["dc.date.issued","2021"],["dc.description.abstract","Context. A long-standing issue in solar ground-based observations has been the contamination of data due to stray light, which is particularly relevant in inversions of spectropolarimetric data. Aims. We aim to build on a statistical method of correcting stray-light contamination due to residual high-order aberrations and apply it to ground-based slit spectra. Methods. The observations were obtained at the Swedish Solar Telescope, and restored using the multi-frame blind deconvolution restoration procedure. Using the statistical properties of seeing, we created artificially degraded synthetic images generated from magneto-hydrodynamic simulations. We then compared the synthetic data with the observations to derive estimates of the amount of the residual stray light in the observations. In the final step, the slit spectra were deconvolved with a stray-light point spread function to remove the residual stray light from the observations. Results. The RMS granulation contrasts of the deconvolved spectra were found to increase to approximately 12.5%, from 9%. Spectral lines, on average, were found to become deeper in the granules and shallower in the inter-granular lanes, indicating systematic changes to gradients in temperature. The deconvolution was also found to increase the redshifts and blueshifts of spectral lines, suggesting that the velocities of granulation in the solar photosphere are higher than had previously been observed."],["dc.identifier.doi","10.1051/0004-6361/201937100"],["dc.identifier.pii","aa37100-19"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/89913"],["dc.notes.intern","DOI Import GROB-469"],["dc.relation.eissn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.title","Correction of atmospheric stray light in restored slit spectra"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A11"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","642"],["dc.contributor.author","Solanki, S. K."],["dc.contributor.author","del Toro Iniesta, J. C."],["dc.contributor.author","Woch, J."],["dc.contributor.author","Gandorfer, A."],["dc.contributor.author","Hirzberger, J."],["dc.contributor.author","Alvarez-Herrero, A."],["dc.contributor.author","Appourchaux, T."],["dc.contributor.author","Martínez Pillet, V."],["dc.contributor.author","Pérez-Grande, I."],["dc.contributor.author","Schmidt, W."],["dc.contributor.author","Lange, T."],["dc.contributor.author","Müller, D."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Müller, R."],["dc.contributor.author","Albert, K."],["dc.contributor.author","Löptien, Björn"],["dc.contributor.author","Meyer, S."],["dc.contributor.author","Soltau, D."],["dc.contributor.author","Schou, Jesper"],["dc.date.accessioned","2021-03-05T08:58:36Z"],["dc.date.available","2021-03-05T08:58:36Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1051/0004-6361/201935325"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/80195"],["dc.notes.intern","DOI Import GROB-393"],["dc.relation.eissn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.title","The Polarimetric and Helioseismic Imager on Solar Orbiter"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A69"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","636"],["dc.contributor.author","Amazo-Gómez, E. M."],["dc.contributor.author","Shapiro, A. I."],["dc.contributor.author","Solanki, S. K."],["dc.contributor.author","Krivova, N. A."],["dc.contributor.author","Kopp, G."],["dc.contributor.author","Reinhold, T."],["dc.contributor.author","Oshagh, M."],["dc.contributor.author","Reiners, A."],["dc.date.accessioned","2021-04-14T08:26:43Z"],["dc.date.available","2021-04-14T08:26:43Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1051/0004-6361/201936925"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/82050"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation.eissn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.title","Inflection point in the power spectrum of stellar brightness variations"],["dc.title.alternative","II. The Sun"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","5"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal. Supplement Series"],["dc.bibliographiccitation.volume","233"],["dc.contributor.author","Gorobets, A. Y."],["dc.contributor.author","Berdyugina, S. V."],["dc.contributor.author","Riethmüller, T. L."],["dc.contributor.author","Rodríguez, J. Blanco"],["dc.contributor.author","Solanki, S. K."],["dc.contributor.author","Barthol, P."],["dc.contributor.author","Gandorfer, A."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Hirzberger, J."],["dc.contributor.author","Noort, M. van"],["dc.contributor.author","Del Toro Iniesta, J. C."],["dc.contributor.author","Suárez, D. Orozco"],["dc.contributor.author","Schmidt, W."],["dc.contributor.author","Pillet, V. Martínez"],["dc.contributor.author","Knölker, M."],["dc.date.accessioned","2020-12-10T18:47:36Z"],["dc.date.available","2020-12-10T18:47:36Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.3847/1538-4365/aa8ef8"],["dc.identifier.eissn","1538-4365"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/78820"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","The Maximum Entropy Limit of Small-scale Magnetic Field Fluctuations in the Quiet Sun"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","28"],["dc.bibliographiccitation.issue","S327"],["dc.bibliographiccitation.journal","Proceedings of the International Astronomical Union"],["dc.bibliographiccitation.lastpage","33"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Manrique, S. J. González"],["dc.contributor.author","Denker, C."],["dc.contributor.author","Kuckein, C."],["dc.contributor.author","Yabar, A. Pastor"],["dc.contributor.author","Collados, M."],["dc.contributor.author","Verma, M."],["dc.contributor.author","Balthasar, H."],["dc.contributor.author","Diercke, A."],["dc.contributor.author","Fischer, C. E."],["dc.contributor.author","Gömöry, P."],["dc.contributor.author","González, N. Bello"],["dc.contributor.author","Schlichenmaier, R."],["dc.contributor.author","Armas, M. Cubas"],["dc.contributor.author","Berkefeld, T."],["dc.contributor.author","Feller, A."],["dc.contributor.author","Hoch, S."],["dc.contributor.author","Hofmann, A."],["dc.contributor.author","Lagg, A."],["dc.contributor.author","Nicklas, H."],["dc.contributor.author","Suárez, D. Orozco"],["dc.contributor.author","Schmidt, D."],["dc.contributor.author","Schmidt, W."],["dc.contributor.author","Sigwarth, M."],["dc.contributor.author","Sobotka, M."],["dc.contributor.author","Solanki, S. K."],["dc.contributor.author","Soltau, D."],["dc.contributor.author","Staude, J."],["dc.contributor.author","Strassmeier, K. G."],["dc.contributor.author","Volkmer, R."],["dc.contributor.author","von der Lühe, O."],["dc.contributor.author","Waldmann, T."],["dc.date.accessioned","2020-12-10T15:22:25Z"],["dc.date.available","2020-12-10T15:22:25Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1017/S1743921317000278"],["dc.identifier.eissn","1743-9221"],["dc.identifier.issn","1743-9213"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/73394"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Flows along arch filaments observed in the GRIS ‘very fast spectroscopic mode’"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","L13"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","776"],["dc.contributor.author","Riethmüller, T. L."],["dc.contributor.author","Solanki, Sami K."],["dc.contributor.author","Hirzberger, Johann"],["dc.contributor.author","Danilovic, S."],["dc.contributor.author","Barthol, P."],["dc.contributor.author","Berkefeld, T."],["dc.contributor.author","Gandorfer, Achim"],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Knölker, M."],["dc.contributor.author","Schmidt, W."],["dc.contributor.author","Toro Iniesta, J. C. del"],["dc.date.accessioned","2017-09-07T11:48:42Z"],["dc.date.available","2017-09-07T11:48:42Z"],["dc.date.issued","2013"],["dc.identifier.doi","10.1088/2041-8205/776/1/l13"],["dc.identifier.gro","3147034"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4768"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","chake"],["dc.publisher","IOP Publishing"],["dc.relation.issn","2041-8205"],["dc.title","FIRST HIGH-RESOLUTION IMAGES OF THE SUN IN THE 2796 Å Mg II k LINE"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1009"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.lastpage","1019"],["dc.bibliographiccitation.volume","589"],["dc.contributor.author","Gizon, L."],["dc.contributor.author","Solanki, S. K."],["dc.date.accessioned","2017-09-07T11:49:45Z"],["dc.date.available","2017-09-07T11:49:45Z"],["dc.date.issued","2003"],["dc.description.abstract","Asteroseismology provides us with the possibility of determining the angle, i, between the direction of the rotation axis of a pulsating Sun-like star and the line of sight. A knowledge of i is important not just for obtaining improved stellar parameters, but also in order to determine the true masses of extrasolar planets detected from the radial velocity shifts of their central stars. By means of Monte Carlo simulations, we estimate the precision of the measurement of i and other stellar parameters. We find that the inclination angle can be retrieved accurately when i gsim 30° for stars that rotate at least twice as fast as the Sun."],["dc.identifier.doi","10.1086/374715"],["dc.identifier.gro","3147431"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5008"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0004-637X"],["dc.title","Determining the Inclination of the Rotation Axis of a Sun‐like Star"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]