adsabs/AstroCLIMB huggingface dataset:
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption: Top: DECam i, g − i CMD for NGC 2808 candidate member stars (black circles) and for candidate field stars (gray) according to the color–color–magnitude selection. The 82 stars in common with the spectroscopic study of Hong et al. (2021) are overplotted as purple (NGC 2808 members) and orange circles (field). Two of the candidate cluster members are not on the RGB (see text for more details). Middle: same stars plotted on the Gaia proper-motion plane. Bottom: the 82 stars with spectroscopy are plotted on the ΔCN vs. ΔCH plane: the four groups identified by Hong et al. are marked with different colors and labeled as G1, G2, G3, and G4. The stars for which we derive the C  ugi  index and separate into three groups are marked with different symbols and labeled as P1, P2, and P3. The 10 stars from Hong et al. that are classified as field members by our color–color–magnitude selection and Gaia proper motions are marked as orange filled circles.
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption:  C  ugi,HST CMDs are shown with the four populations from Latour et al. (2019), which were identified using chromosome maps that include the F275W filter, indicated as large orange, brown, cyan, and magenta circles. The open symbols represent the HST-equivalent P1 (blue), P2 (green), and P3 (red) populations identified in Figure 8 for our DECam data and use the same color/symbol shape scheme. The small light-gray circles illustrate the full width of the C  ugi,HST color range. The comparison shows that the P1 group from Latour et al. (2019) is strongly mapped to our P1 group, their P2 group is relatively well aligned with our P2 group, and their P3/P4 groups are a mixture of our P2 and P3 groups. This figure highlights the strong correlation between the C  ugi,HST index and similar indices that use F275W.
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption: Left: normalized isodensity contours are shown for the P1 (top), P2 (middle), and P3 (bottom) populations. The data are normalized such that the illustrated fraction is relative to the highest-density bin for each population. The intersection of the dashed purple lines highlights the adopted cluster center. Right: the color scale map shows a similar normalized density distribution to the left panels, but using all stars in the cluster. The black contours are the same in each panel and illustrate the density distributions of the entire cluster. The blue, green, and red contours are the same relative density levels for the P1, P2, and P3 populations, respectively. The panels indicate that the P3 group is off-center from the P1 + P2 populations and also show that the P3 stars are more broadly distributed. The bottom right panel also indicates that the P3 stars may be aligned with a slightly different position angle than the rest of the cluster.
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption: Top left: normalized radial distributions are shown for the P1 (blue), P2 (green), and P3 (red) populations inside 1.′5 from the cluster center. The data are binned in 0.′1 increments and are normalized relative to the most populated bin for each group. Bottom left: a similar plot using 0.′5 bins but extending out to about 70% of the tidal radius. Top right: cumulative radial distributions are shown for the three NGC 2808 populations using the same colors as the left panels. Bottom right: a similar cumulative distribution extending out to the tidal radius. These panels show that the P3 group is centrally concentrated inside about 1 half-light radius (0.′8) and then becomes more dispersed in the outer parts of the cluster. Similarly, the P2 group is the most centrally concentrated between about 1 and 5 half-light radii.
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption: Left: r, g − i CMD based on HST photometry for radial distances ≤1.′5 from the center of NGC 2808. Selected RGB, AGB, MS, and RHB stars are shown as green, orange, yellow, and red filled circles, respectively, while the blue HB stars, divided into the three groups EBT1, EBT2, and EBT3, are overplotted as magenta, cyan, and blue filled circles, respectively. Right: same as the left panel, but for distances > 1.′5 and based on DECam photometry. Note that the HST photometry has been transformed onto the DECam photometric system (see text for more details).
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption: The various histograms show the optimal number of components derived from GMM realizations of the data using the BIC with all components sharing the same covariance matrix (“tied”; green), each component having a separate diagonal covariance matrix (“diagonal”; red), each component having its own covariance matrix (“full”; blue), and each component having a single variance value (“spherical”; yellow). The magenta histogram shows similar results but using the Akaike information criterion (AIC). Most methods found that a three-component fit was the optimal number.
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption: Top: R parameter plotted as a function of distance from the cluster center and based on HST and DECam star counts. Middle: same as the top panel, but for the ratio of the number of RGB and MS stars. Bottom: same as the top panel, but for the ratio of the number of HB and MS stars.
Paper: A Wide View of the Galactic Globular Cluster NGC 2808: Red Giant and Horizontal Branch Star Spatial Distributions
Authors: Christian I. Johnson, Annalisa Calamida, Justin A. Kader, Ivan Ferraro, Catherine A. Pilachowski, Giuseppe Bono, Alessandra Mastrobuono-Battisti, Armin Rest, Alfredo Zenteno, Alice Zocchi
Figure caption: Top: r-band luminosity distribution of the different HB groups in NGC 2808, RHB, EBT1, EBT2, and EBT3, respectively, for radial distances from the cluster center ≤1.′5 and based on HST photometry. Bottom: same as the top panel, but for distances > 1.′5 and based on DECam photometry.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: The mass–rotation diagram for our active sample. The six stars without measured rotation periods are noted by vertical lines (we are able to include LEP 2240-4931 AB in the scatter plot despite not knowing which component is responsible for which period, as the pair is an equal-mass binary). For three of the six, we place an upper limit on the rotation period using our vsini measurement. The red dashed line represents a linear regression over all stars with periods less than 20 days, suggesting a weak positive correlation between the rotation periods of rapidly rotating M dwarfs and mass. This line is defined by the equation ﹩{\mathrm{log}}_{10}({P}_{\mathrm{rot}})=-0.61+3.2{M}_{* }﹩, with P rot in days and M * in solar masses. For comparison, the sample from Newton et al. (2016, 2018) is shown as smaller points in the background; that sample includes both active and inactive stars.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: The spectroscopic vsini and photometric v for our 115 stars with measured rotation periods. Detections of rotational broadening less than 3.4 km s−1 are consistent with zero given our spectrograph resolution. Colored lines indicate constant inclination. The y-axis error bars illustrate 5% uncertainties on the radii and the x-axis error bars show the range of vsini measurements observed for each star. No stars should fall below the red i = 90° line, although we observe a small number of interlopers in this region. We discuss possible reasons for these outliers in the text.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: In the upper panel, we show a histogram of the photometric peak-to-peak amplitudes of stars with P rot measured from TESS or MEarth, separated into the same two Hα bins as in Figure 6. In orange, we show inactive (Hα > −1 Å) stars with P rot from TESS or MEarth, using amplitudes tabulated in Medina et al. (2022b). Like the active stars, these inactive stars are part of the 15 pc sample of 0.1–0.3 M ⊙ M dwarfs and have been vetted for close binary companions. The lower panel shows these same data in the amplitude–rotation-period plane. Highly active stars tend to have larger amplitudes than modestly active or inactive stars.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: A simplified version of Figure 5. Here we split our sample into two equally sized groups: stars that are highly active (Hα < −4 Å, shown in purple) and those that are more modestly active (Hα > −4 Å, shown in green). Within the rapidly rotating mode, the highly active stars tend to have shorter rotation periods and the modestly active stars tend to have longer ones.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: In solid blue, we show the cumulative distribution of inclinations for the 90 stars with v > 3.4 km s−1. In transparent blue, we show 10 random draws consistent with the uncertainties in our observed parameters; we assume 5% uncertainties on the radii and a uniform range of vsini between the minimum value and the maximum value we observe for each star. The solid orange line shows an isotropic distribution of spin axes. In transparent orange, we show 10 random draws from the isotropic distribution given our sample size.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: The phased sector 35–37 PDCSAP light curve for TIC 342888849, containing LHS 2004 and LHS 2005 AB. This target was also observed in sectors 8–10, exhibiting similar signals, but the spot pattern evolves sufficiently over two years that we omit the earlier sectors from the plot for clarity. The top panel shows the 1.174 day signal, the middle shows the 0.139 day signal, and the bottom shows the 0.210 day signal. In each case, the models of the other two signals have been removed. The points show 500 bins evenly spaced in phase. The best-fitting spot model is in red. To sufficiently model the detail in signal a, we include sinusoids for the fundamental mode and four harmonics. We only require the fundamental mode and the first harmonic for b and c.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: The phased sector 1 PDCSAP light curve for TIC 161174284, containing LEP 2240-4931 AB. The top panel shows the 1.002 day signal (with the 0.598 day model removed) while the bottom panel shows the smaller 0.598 day signal (with the 1.002 day model removed). The points show 500 bins evenly spaced in phase. The best-fitting spot model is in red, which includes sinusoids for the fundamental mode and the first harmonic.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: Hα emission for our TRES stars. Individual spectra are shown as colored lines, with the median spectrum in black. Note the y-axis scale varies between rows, with the most active stars shown at the top of the figure.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: Same as Figure 1, but for our CHIRON stars.
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: A color–magnitude diagram of the 15 pc sample of 0.1–0.3 M ⊙ M dwarfs without close binary companions, with magnitudes from Gaia and 2MASS. The 123 active stars are from this work while the 200 inactive stars are described in Pass et al. (2023). Black × symbols denote stars with measured peak-to-peak photometric amplitudes exceeding 0.01 mag, including 12 inactive stars with measurements tabulated in Medina et al. (2022b). Candidate members of young moving groups are labeled. At a given K-band magnitude, more active stars generally exhibit redder colors. This behavior does not necessarily indicate these stars are overluminous due to youth: within a coeval cluster, more rapidly rotating M dwarfs have been found to be redder, perhaps due to decreased temperatures resulting from high starspot coverage (e.g., Covey et al. 2016).
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: In the upper panel, we show 13 radial velocities of LHS 2320 collected between 2020 December and 2021 May, phased to the star’s 0.692 day rotation period. Most observations of LHS 2320 have Hα equivalent widths between −6 and −10 Å; however, two observations feature Hα spikes to nearly −20 Å. These two epochs are indicated in red, as the flares may affect our RV measurements (as in, for example, Robertson et al. 2020). Observations appear clustered when phased by the rotation period. In particular, the four highest RV measurements all occur at the same phase. In the lower panel, we show the photometric variability of the star as observed by TESS and MEarth. While MEarth observed this star for over a decade (pale triangles), we highlight the observations that are contemporaneous with the RV observations (blue triangles). The TESS observations offer higher precision but were taken in 2021 November/December (i.e., they are not contemporaneous). We see that the time of maximal flux corresponds to ΔRV near 0, as expected (e.g., see Figure 11 of Boisse et al. 2012).
Paper: Active Stars in the Spectroscopic Survey of Mid-to-late M Dwarfs within 15 pc
Authors: Emily K. Pass, Jennifer G. Winters, David Charbonneau, Jonathan M. Irwin, Amber A. Medina
Figure caption: We plot our simple prediction of RV jitter: the photometric amplitude multiplied by vsini. This estimate correlates with the sample standard deviation we observe in our RV time series. The blue line indicates unity, with the shaded region showing agreement within a factor of 2. We show the 39 stars with resolved rotational broadening (vsini > 3.4 km s−1), measured photometric amplitudes, and whose predicted RV jitter is larger than that star’s median RV uncertainty.
Paper: Wavelength-dependent Extinction and Grain Sizes in “Dippers”
Authors: Michael L. Sitko, Ray W. Russell, Zachary C. Long, Korash Assani, Monika Pikhartova, Ammar Bayyari, Carol A. Grady, Carey M. Lisse, Massimo Marengo, John P. Wisniewski, William C. Danchi
Figure caption: The region near He I line for EPIC 204638512 on two consecutive nights, along with the spectrum of HD 3765, a star of similar spectral type, taken from the SpeX Atlas of Cool Stars (Rayner et al. 2009). The gap in the data on EPIC 204628512 is the result of trimming out the spectrum heavily affected by telluric absorption. Also shown are the locations of two nearby hydrogen lines, often seen in emission in stars actively accreting material from their disks, and the He I line. The Pa β line is weaker than in HD 3765, suggesting it might be weakly in emission, partially filling the photospheric absorption line (in K2 V stars this region also contains a blend of Ti I, Ni I, Fe I, and Ca I lines—see Figure 30 of Rayner et al. 2009). In the brighter continuum state, the He I line exhibits a weak emission component in addition to a strong absorption core at shorter wavelengths. This resembles a P Cygni-like profile, but with a relatively stronger short wavelength absorption component. In the higher dust occultation data, the red wing of the He I line is not evident.
Paper: Wavelength-dependent Extinction and Grain Sizes in “Dippers”
Authors: Michael L. Sitko, Ray W. Russell, Zachary C. Long, Korash Assani, Monika Pikhartova, Ammar Bayyari, Carol A. Grady, Carey M. Lisse, Massimo Marengo, John P. Wisniewski, William C. Danchi
Figure caption: Extinction curve of EPIC 204638512. The model curves labeled “CCM”. are those of Cardelli et al. (1989), using different values of R  V , and representative of ISM extinction. Also shown are DMC extinction curves from McClure (2009) and Weingartner & Draine (2001). The curves labeled “ww04,” “www003,” and “ww002” are grain files included with the HOCHUNK3D code package of Whitney et al. (2013). For example, “www003”’ is Model 1 of Wood et al. (2002), which has a power-law grain size distribution, with a maximum grain size of 1000 μm and an exponential cutoff at starting an 50 μm and going to the large grain limit. “Modified KMH” uses the grain size distribution of Kim et al. (1994) but increasing the minimum and maximum grain sizes to 0.25 μm and 500 μm, respectively. These are described more fully in the text.
Paper: Wavelength-dependent Extinction and Grain Sizes in “Dippers”
Authors: Michael L. Sitko, Ray W. Russell, Zachary C. Long, Korash Assani, Monika Pikhartova, Ammar Bayyari, Carol A. Grady, Carey M. Lisse, Massimo Marengo, John P. Wisniewski, William C. Danchi
Figure caption: 0.7–2.4 μm spectra of three dippers obtained with the SpeX spectrograph between 0.7 and 2.4 μm on 2017 August 10 and 11 (UT). Due to poor signal/noise, the spectrum of EPIC 203850058 was truncated at wavelengths smaller than 0.8 μm. The spectra were calibrated in absolute flux using K-band images obtained with the guide camera (filled circles). For EPIC 204628512 and EPIC 205151387, the fainter spectrum was also slightly redder, and were used to examine the wavelength dependence of the extinction (reddening). The difference in the flux levels for EPIC 2035850058 were so small that we did not attempt to derive a flux ratio for examining potential reddening by dust.(The data used to create this figure are available.)
Paper: Wavelength-dependent Extinction and Grain Sizes in “Dippers”
Authors: Michael L. Sitko, Ray W. Russell, Zachary C. Long, Korash Assani, Monika Pikhartova, Ammar Bayyari, Carol A. Grady, Carey M. Lisse, Massimo Marengo, John P. Wisniewski, William C. Danchi
Figure caption: Extinction curve of EPIC 205151387. The grain models are explained in the caption to Figure 2, except we did not include grain models used in the HOCHUNK3D package; however, it is clear that the grain sizes involved are similar to those in EPIC 204638512. The change in the He I feature is more pronounced in EPIC 205151387.
Paper: Wavelength-dependent Extinction and Grain Sizes in “Dippers”
Authors: Michael L. Sitko, Ray W. Russell, Zachary C. Long, Korash Assani, Monika Pikhartova, Ammar Bayyari, Carol A. Grady, Carey M. Lisse, Massimo Marengo, John P. Wisniewski, William C. Danchi
Figure caption: The region near He I line for EPIC 203850058 on two consecutive nights, along with the spectrum of Wolf 47, a star of similar spectral type, taken from the SpeX Atlas of Cool Stars (Rayner et al. 2009). The Pa β and Pa γ lines are in emission, suggesting some accreting gas. The He I line exhibits absorption, but unlike EPIC 204638512 and EPIN 501551387, does not show a detectable He I emission component, although the quality of the spectra are inferior to those of the other two dippers. Note that Wolf 47 is a dMe star exhibiting flares (including at radio wavelengths; White et al. 1989) and so some line emission (Pa γ?) is not unexpected.
Paper: Wavelength-dependent Extinction and Grain Sizes in “Dippers”
Authors: Michael L. Sitko, Ray W. Russell, Zachary C. Long, Korash Assani, Monika Pikhartova, Ammar Bayyari, Carol A. Grady, Carey M. Lisse, Massimo Marengo, John P. Wisniewski, William C. Danchi
Figure caption: The region near He I line for EPIC 205151387 on two consecutive nights, along with the spectrum of HD 209290, a star of similar spectral type, taken from the SpeX Atlas of Cool Stars (Rayner et al. 2009). During the dust extinction event (lower net flux) , the He I absorption line became even stronger than in EPIC 204628512, The Pa β line developed a distinct absorption component, and the emission on Pa γ was weakened. The absorption in He I and Pa β are both shifted toward longer wavelengths than the emission, inverse P Cygni-like profiles, indicating infalling gas.
Paper: Precise Age for the Binary Star System 12 Com in the Coma Berenices Cluster
Authors: Rex Lam, Eric L. Sandquist, Gail H. Schaefer, Christopher D. Farrington, John D. Monnier, Narsireddy Anugu, Cyprien Lanthermann, Robert Klement, Jacob Ennis, Benjamin R. Setterholm, Tyler Gardner, Stefan Kraus, Claire L. Davies, Jerome A. Orosz
Figure caption: Relative orbit for 12 Com B with respect to 12 Com A, represented by the star at (0,0). The purple and black points show the model-predicted positions of the secondary star at the time of PTI and CHARA observations, respectively. Positions derived from the visibilities are coincident with the model-predicted positions. The orange ellipses show a 10σ uncertainty around the calculated positions. The yellow line connects 12 Com A to the periastron.
Paper: Precise Age for the Binary Star System 12 Com in the Coma Berenices Cluster
Authors: Rex Lam, Eric L. Sandquist, Gail H. Schaefer, Christopher D. Farrington, John D. Monnier, Narsireddy Anugu, Cyprien Lanthermann, Robert Klement, Jacob Ennis, Benjamin R. Setterholm, Tyler Gardner, Stefan Kraus, Claire L. Davies, Jerome A. Orosz
Figure caption: Fits to the interferometric data for the giant 31 Com. The color points show observations with different baselines in the CHARA array, and the black points show the best model fits. Labels give the Julian date of observation–2400000.