- ID:
- ivo://CDS.VizieR/J/ApJS/235/23
- Title:
- LEGUS galaxies1 observations
- Short Name:
- J/ApJS/235/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle 21 Treasury program on the Hubble Space Telescope. It studied 50 nearby star-forming galaxies in 5 bands from the near-UV to the I-band, combining new Wide Field Camera 3 observations with archival Advanced Camera for Surveys data. LEGUS was designed to investigate how star formation occurs and develops on both small and large scales, and how it relates to the galactic environments. In this paper we present the photometric catalogs for all the apparently single stars identified in the 50 LEGUS galaxies. We present optical and near-UV color-magnitude diagrams for all the galaxies. For each galaxy we derived the distance from the tip of the red giant branch. We then used the NUV color-magnitude diagrams to identify stars more massive than 14M_{sun}_, and compared their number with the number of massive stars expected from the GALEX FUV luminosity. Our analysis shows that the fraction of massive stars forming in star clusters and stellar associations is about constant with the star formation rate. This lack of a relation suggests that the timescale for evaporation of unbound structures is comparable or longer than 10Myr. At low star formation rates this translates to an excess of mass in clustered environments as compared to model predictions of cluster evolution, suggesting that a significant fraction of stars form in unbound systems.
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1532. Leo I VI photometry
- ID:
- ivo://CDS.VizieR/J/MNRAS/354/708
- Title:
- Leo I VI photometry
- Short Name:
- J/MNRAS/354/708
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present V and I photometry of a 9.4'x9.4' field centered on the dwarf spheroidal galaxy Leo I. The I magnitude of the tip of the Red Giant Branch is robustly estimated from two different datasets I^TRGB^=17.97 (^+0.05^_-0.03_). From this estimate, adopting [M/H]~-1.2 from the comparison of RGB stars with Galactic templates, we obtain a distance modulus (m-M)_0=22.02+/-0.13, corresponding to a distance D=254^+16^_-19_kpc.
- ID:
- ivo://CDS.VizieR/J/PASP/117/676
- Title:
- LHS faint proper-motion stars
- Short Name:
- J/PASP/117/676
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present low-resolution spectroscopic observations of faint proper-motion stars from the LHS Catalogue, concentrating on stars with m_r_>16.5 and {mu}>0.5"/yr. The present paper includes observations and spectral classifications for 294 M dwarfs, M subdwarfs (sdM), and extreme M subdwarfs (esdM). We also identify white dwarfs among the faintest LHS stars. We have cross-referenced this sample against the Two Micron All Sky Survey (2MASS) sources, and list data for the detected objects. We discuss stars of individual interest, as well as the characteristics of the overall sample. As expected, a significant number of the stars in this proper-motion-selected sample are halo subdwarfs, including an esdM dwarf, LHS 3481, that is likely to lie within 20pc of the Sun. None of the subdwarfs show H{alpha} emission.
1534. LH 47 UVBRI photometry
- ID:
- ivo://CDS.VizieR/J/A+AS/123/455
- Title:
- LH 47 UVBRI photometry
- Short Name:
- J/A+AS/123/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 3 lists the final photometric data of our observations. The UBVRI observations were done with the 1.54m Danish telescope at ESO on October 3rd and 4th, 1992. The CCD was ESO#28, a TEK 1024x1024 with a pixel size of 24mue corresponding to 0.377" per pixel. The total field of view is 6.4'x6.4'. A standard reduction was done with MIDAS and IRAF, the photometry was performed with DAOPHOT within IRAF. The images of Oct 4th have been calibrated using the calibration field around PG 0231+051 (Landolt 1992, Cat. <II/183>). The images of Oct 3rd have then been adopted to the system of Oct 4th. The final Table 3 lists 4613 stars with V and B-V information. In addition U-B is available for 1159 of these stars, V-R for 3519 and V-I for 2854 stars. Table 4 gives those stars from our field of view which are present in the MACS (Magellanic Catalogue of Stars; Tucholke et al. 1996, Cat. <I/221>). The table contains the MACS Id., our x and y position and our UBV photometry, and right ascension and declination from the MACS. These stars may serve to calculate an exact position for every star from Table 3 or to define a coordinate grid for comparison with other observations, such as radio or X-ray data.
- ID:
- ivo://CDS.VizieR/J/AJ/162/7
- Title:
- Light curve and radial velocities for 7 host stars
- Short Name:
- J/AJ/162/7
- Date:
- 18 Mar 2022 09:35:03
- Publisher:
- CDS
- Description:
- We report the discovery and characterization of seven transiting exoplanets from the HATNet survey. The planets, which are hot Jupiters and Saturns transiting bright Sun-like stars, include: HAT-P-58b (with mass M_p_=0.37M_J_, radius R_p_=1.33R_J_, and orbital period P=4.0138days), HAT-P-59b (M_p_=1.54M_J_, R_p_=1.12R_J_, P=4.1420days), HAT-P-60b (M_p_=0.57M_J_, R_p_=1.63R_J_, P=4.7948days), HAT-P-61b (M_p_=1.06M_J_, R_p_=0.90R_J_, P=1.9023days), HAT-P-62b (M_p_=0.76M_J_, R_p_=1.07R_J_, P=2.6453days), HAT-P-63b (M_p_=0.61M_J_, R_p_=1.12R_J_, P=3.3777days), and HAT-P-64b (M_p_=0.58M_J_, R_p_= 1.70R_J_, P=4.0072days). The typical errors on these quantities are 0.06M_J_, 0.03R_J_, and 0.2s, respectively. We also provide accurate stellar parameters for each of the host stars. With V=9.710{+/-}0.050mag, HAT-P-60 is an especially bright transiting planet host, and an excellent target for additional follow-up observations. With R_p_=1.703{+/-}0.070R_J_, HAT-P-64b is a highly inflated hot Jupiter around a star nearing the end of its main-sequence lifetime, and is among the largest known planets. Five of the seven systems have long-cadence observations by TESS which are included in the analysis. Of particular note is HAT-P-59 (TOI-1826.01) which is within the northern continuous viewing zone of the TESS mission, and HAT-P-60, which is the TESS candidate TOI-1580.01.
- ID:
- ivo://CDS.VizieR/J/AJ/133/255
- Title:
- Light-curve and radial velocities of BD+42 2782
- Short Name:
- J/AJ/133/255
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BD+42 2782 was recently discovered to be a variable star with a W UMa-type, eclipsing-binary light curve. We have obtained the first photoelectric light curves (R_C_, I_C_) and also the first radial velocity curves for this binary.
- ID:
- ivo://CDS.VizieR/J/ApJ/654/L25
- Title:
- Light-curve data for GRB 050319
- Short Name:
- J/ApJ/654/L25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multiwavelength observations of the optical afterglow of GRB 050319 were performed from 1.31 to 9.92hr after the burst. Our R-band light curves, combined with other published data, can be described by the smooth broken power-law function, with {alpha}_1_=-0.84+/-0.02 to {alpha}_2_=-0.48+/-0.03, 0.04 days after the gamma-ray burst. The optical light curves are characterized by shallow decays as was also observed in the X-rays which may have a similar origin, related to energy injection. However, our observations indicate that there is still a puzzle concerning the chromatic breaks in the R-band light curve (at 0.04 days) and the X-ray light curve (at 0.004 days) that remains to be solved.
- ID:
- ivo://CDS.VizieR/J/ApJ/664/1154
- Title:
- Light curve of 2MASS J05352184-0546085
- Short Name:
- J/ApJ/664/1154
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The newly discovered brown dwarf eclipsing binary 2MASS J05352184-0546085 provides a unique laboratory for testing the predictions of theoretical models of brown dwarf formation and evolution. The finding that the lower mass brown dwarf in this system is hotter than its higher mass companion represents a challenge to brown dwarf evolutionary models, none of which predict this behavior. Here we present updated determinations of the basic physical properties of 2M0535-05, bolstering the surprising reversal of temperatures with mass in this system. We compare these measurements with widely used brown dwarf evolutionary tracks, and find that the temperature reversal can be explained by some models if the components of 2M0535-05 are mildly non-coeval, possibly consistent with dynamical simulations of brown dwarf formation. Alternatively, a strong magnetic field on the higher mass brown dwarf might explain its anomalously low surface temperature, consistent with emerging evidence that convection is suppressed in magnetically active, low-mass stars. Finally, we discuss future observational and theoretical work needed to further characterize and understand this benchmark system.
- ID:
- ivo://CDS.VizieR/J/AJ/161/15
- Title:
- Light curve of the dwarf nova AT 2020iko
- Short Name:
- J/AJ/161/15
- Date:
- 08 Dec 2021
- Publisher:
- CDS
- Description:
- The ongoing Zwicky Transient Facility (ZTF) survey is generating a massive alert rate from a variety of optical transients and variable stars, which are being filtered down to subsets meeting user-specified criteria by broker systems such as the Arizona-NOIRLab Temporal Analysis and Response to Events System (ANTARES). In a beta implementation of the algorithm of Soraisam et al. on ANTARES, we flagged AT 2020iko from the ZTF real-time alert stream as an anomalous source. This source is located close to a red extended Sloan Digital Sky Survey source. In the first few epochs of detection, it exhibited a V-shaped brightness profile, preceded by nondetections both in ZTF and in the All-Sky Automated Survey for Supernovae extending to 2014. Its full light curve shows a precursor event, followed by a main superoutburst and at least two rebrightenings. A low-resolution spectrum of this source points to a dwarf nova (DN) nature. Although some of the features of AT 2020iko indicate an SU UMa-type DN, its large amplitude, presence of rebrightenings, and inferred supercycle period of >~6yr are in favor of AT 2020iko being a new WZ Sge- type DN candidate, a subset of rare DNe consisting of extreme mass-ratio (<0.1) binaries with an orbital period around the period minimum. The precusor event of AT 2020iko brightened by 6.5mag, while its decay spanned 3-5mag. We speculate this superoutburst is associated with a less expanded accretion disk than in typical superoutbursts in WZ Sge systems, with the large depth of the precursor decay implying an extremely small mass ratio. To the best of our knowledge, such a precursor event has not been recorded for any DN. This result serves to demonstrate the efficacy of our real-time anomaly search algorithm.
- ID:
- ivo://CDS.VizieR/J/ApJ/773/55
- Title:
- Light curve of T Pyx from 1890 to 2011
- Short Name:
- J/ApJ/773/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery by M. Linnolt on JD 2455665.7931 (UT 2011 April 14.29) of the sixth eruption of the recurrent nova T Pyxidis. This discovery was made just as the initial fast rise was starting, so with fast notification and response by observers worldwide, the entire initial rise was covered (the first for any nova), and with high time resolution in three filters. The speed of the rise peaked at 9mag/day, while the light curve is well fit over only the first two days by a model with a uniformly expanding sphere. We also report the discovery by R. Stubbings of a pre-eruption rise starting 18 days before the eruption, peaking 1.1mag brighter than its long-time average, and then fading back toward quiescence 4 days before the eruption. This unique and mysterious behavior is only the fourth known (with V1500 Cyg, V533 Her, and T CrB) anticipatory rise closely spaced before a nova eruption. We present 19 timings of photometric minima from 1986 to 2011 February, where the orbital period is fast increasing with P/dot{P}=+313000yr. From 2008 to 2011, T Pyx had a small change in this rate of increase, so that the orbital period at the time of eruption was 0.07622950+/-0.00000008 days. This strong and steady increase of the orbital period can only come from mass transfer, for which we calculate a rate of (1.7-3.5)x10^-7^M_{sun}_/yr. We report 6116 magnitudes between 1890 and 2011, for an average B=15.59+/-0.01 from 1967 to 2011, which allows for an eruption in 2011 if the blue flux is nearly proportional to the accretion rate. The ultraviolet-optical-infrared spectral energy distribution is well fit by a power law with f_{nu}_{prop.to}{nu}^1.0^, although the narrow ultraviolet region has a tilt with a fit of f_{nu}_{prop.to}{nu}^1/3^.
