1,733,787 research outputs found
Union Pacific (UP) 4915
No full textA photograph print showing Union Pacific (UP) 4915, 0-6-0 switch engine, Albina, OR (?)
No Maunder Minimum phase in HD 4915
No full textContext. The long-term solar magnetic activity and its cyclical behaviour, which is maintained by a dynamo mechanism, are both still challenging problems for astrophysics. In particular, an atypical event occurred between 1645 and 1715, when the solar activity was remarkably decreased and the number of sunspots was extremely reduced. However, the exact events that unfolded during the solar cycle remain unclear. The discovery of longer activity minima in cool stars may shed light on the nature of the complex mechanisms involved in the long-term behaviour of the solar-stellar dynamo.
Aims. Our aim is to explore whether the G5V solar-like star HD 4915, which showed a striking chromospheric activity pattern in a previous study performed with HIRES data, might be considered a bona fide Maunder Minimum (MM) candidate.
Methods. We analysed over 380 spectra acquired between 2003 and 2022 using the HARPS and HIRES spectrographs. We carried out a detailed search for activity signatures in HD 4915 by using the Mount Wilson and the Balmer Hα activity indexes. This task was performed by means of the generalised Lomb-Scargle periodogram.
Results. The new HARPS data show that the chromospheric activity of HD 4915 is not decreasing. In fact, the increases in the activity after the broad minimum in three years reaches the level of activity before this phase, suggesting that it is not entering an MM phase. We also calculate a rotation period of 23.4 ± 0.2 d, which has not been reported before.
Conclusions. HD 4915 shows a distinctive activity behaviour that was initially attributed to a possible and incipient MM phase. Additional HARPS data allowed us to discard an MM in the star. Our analysis shows that the complex activity pattern of HD 4915 might be ruled by a multiple activity cycle, in which a shorter cycle of 4.8 yr is modulated by a potential longer cycle. More activity surveys with extensive records and suitable cadence are crucial for an accurate identification of stars in magnetic grand minima
Block Card 4915 Elm Place
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Ranch houses | 4915 Elm Place (Toledo, Ohio) | Dwelling | Deveaux Area (Toledo, Ohio
Letter re: H. R. 4915
No full textLetter to Amon Giles Carter Sr. from Tom Connally stating that the Senate has introduced a bill similar to H. R. 4915 and he will be in favor of Texas highway legislatio
No Maunder Minimum phase in HD 4915
Get PDFThe long-term solar magnetic activity and its cyclical behaviour, which is maintained by a dynamo mechanism, are both still challenging for the astrophysics. In particular, an atypical event occurred between 1645 and 1715 when the solar activity was remarkably decreased and the number of sunspots got extremely reduced. However, it is still unclear what happened to the solar cycle. The discovery of longer activity minima in cool stars may shed light on the nature of the complex mechanisms involved in the long-term behaviour of the solar-stellar dynamo. Our aim is to explore if the G5V solar-like star HD 4915, which showed a striking chromospheric activity pattern in a previous study performed with HIRES data, could be considered a bona fide Maunder Minimum (hereafter MM) candidate. We have analyzed over 380 spectra acquired between 2003 and 2022 using HARPS and HIRES spectrographs. We carried out a detailed search of activity signatures in HD 4915 by using the Mount Wilson and the Balmer H activity indexes. This task was performed by means of the GLS periodogram. The new HARPS data show that the chromospheric activity of HD 4915 is not decreasing. In fact, the rise of the activity after the broad minimum in three years gets to the level of activity before that phase, suggesting that it is not entering into a MM phase. HD 4915 shows a distinctive activity behaviour initially attributed to a possible and incipient MM phase. The additional HARPS data allow us to discard a MM in the star. Our analysis shows that the complex activity pattern of HD 4915 could be ruled by a multiple activity cycle, being a shorter cycle of 4.8-yr modulated by a potential longer one. More activity surveys with extensive records and suitable cadence are crucial for accurate identification of stars in Magnetic Grand Minima.(5 pages, 4 figures
Block Card 4915 Bowser Drive
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Dwelling | 4915 Bowser Drive (Toledo, Ohio) | Ranch houses | Deveaux Area (Toledo, Ohio) | West Toledo area (Toledo, Ohio) | Hipped roo
Block Card 4915 Burnham Avenue
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: dwelling | 4915 Burnham Aveue (Toledo, Ohio) | Colonial Revival Style | North Toledo (Toledo, Ohio) | Willys Park area (Toledo, Ohio) | Alfred Bailey Addition (Toledo, Ohio
Block Card 4915 Cedarhurst Road
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Ranch Style | Dwelling | 4915 Cedarhurst Road (Toledo, Ohio) | Elmhurst Park Addition (Toledo, Ohio) | Deveaux Area (Toledo, Ohio) | West Toledo (Toledo, Ohio
Dan Greenwood home, 4915 Dexter Avenue, Fort Worth, Texas
No full textFort Worth. City of. Residences. Exterior shot of the Dan Greenwood home, 4915 Dexter.https://mavmatrix.uta.edu/specialcollections_startelegram1950s/28793/thumbnail.jp
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