- ID:
- ivo://CDS.VizieR/J/ApJS/111/445
- Title:
- Spectra of normal stars in the K band
- Short Name:
- J/ApJS/111/445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An Atlas of 115 medium-resolution K-band (2.0-2.4um) stellar spectra, spanning spectral types O-M and luminosity types I-V, is presented. K-band spectra are also presented for one N- and one J-type carbon star. A time series of spectra is presented for an S-type Mira variable. All the spectra are at a resolution of ~3000 (1.4cm^-1^) and have had the terrestrial absorption removed by dividing a featureless spectrum. The spectra are plotted with the major spectral features identified and are available digitally.
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- ID:
- ivo://CDS.VizieR/J/AJ/124/3393
- Title:
- Spectra of normal stars in the L-band
- Short Name:
- J/AJ/124/3393
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a brief atlas of L-band (3.3-4.2um) spectra for 42 stars plus the Sun and a sunspot observed at a resolving power of R~3000. This contribution is intended to supplement our previous K-band, H-band, and J-band spectral atlases. The L-band data, which cover some or all of the 2400 to 3000cm^-1^ (3.3-4.2um) region, are mainly for luminous late-type stars. In reducing these data, special care has been taken to remove telluric features, especially water vapor. We identify temperature- and luminosity-sensitive atomic and molecular indices to aid in the classification of stellar spectra in the L band.
- ID:
- ivo://CDS.VizieR/J/A+A/452/567
- Title:
- Spectra of Nova Scuti 2005 N.2 (V477 Sct)
- Short Name:
- J/A+A/452/567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our CCD photometry of Nova Scuti 2005 N.2 (=V477 Sct) shows it to be a very fast nova, which is characterized by t_2_=3 and t3_=_6 days, affected by a E(B-V)>=1.3mag reddening, and which peaked at V~9.8mag on ~Oct. 12.0 UT. The nova was probably entering a dust condensation episode or brightness oscillations during the transition phase when it became unobservable for the seasonal conjunction with the Sun. Absolute spectrophotometry shows it to belong to the He/N class. The emission line width at half intensity is 2600km/s. At least five ripples are identified in the high resolution emission lines profiles at radial velocities ranging from -980 to +700km/s. The nova erupted at a large distance from the Sun and at an appreciable height above the Galactic plane, suggesting an association with the Galactic bulge (unusual for a He/N nova). The progenitor was too faint to be recorded on DSS1/2 survey plates, when setting the outburst amplitude to DeltaV>=11mag.
17164. Spectra of 12 ON stars
- ID:
- ivo://CDS.VizieR/J/A+A/578/A109
- Title:
- Spectra of 12 ON stars
- Short Name:
- J/A+A/578/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material is observed at the surface of O and B stars. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle is not known. Our goal is to answer this question. We performed a spectroscopic analysis of a sample of ON stars with atmosphere models. We determined the fundamental parameters as well as the He, C, N, and O surface abundances. We also measured the projected rotational velocities. We compared the properties of the ON stars to those of normal O stars.
- ID:
- ivo://CDS.VizieR/J/A+A/614/A135
- Title:
- Spectra of 78 PN central stars
- Short Name:
- J/A+A/614/A135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are more than 3000 known Galactic planetary nebulae (PNe), but only 492 central stars of Galactic planetary nebulae (CSPN) have known spectral types. It is vital to increase this number in order to have reliable statistics, which will lead to an increase of our understanding of these amazing objects. We aim to contribute to the knowledge of central stars of planetary nebulae and stellar evolution. This observational study is based on Gemini Multi-Object Spectrographs (GMOS) and with the Intermediate Dispersion Spectrograph (IDS) at the Isaac Newton Telescope (INT) spectra of 78 CSPN. The objects were selected because they did not have any previous classification, or the present classification is ambiguous. These new high quality spectra allowed us to identify the key stellar lines for determining spectral classification in the Morgan-Keenan (MK) system. We have acquired optical spectra of a large sample of CSPN. From the observed targets, 50 are classified here for the first time while for 28 the existing classifications have been improved. In seven objects we have identified a P-Cygni profile at the HeI lines. Six of these CSPN are late O-type. The vast majority of the stars in the sample exhibit an absorption-type spectrum, and in one case we have found wide emission lines typical of [WR] stars. We give a complementary, and preliminary, classification criterion to obtain the sub-type of the O(H)-type CSPN. Finally, we give a more realistic value of the proportion of CSPN that are rich or poor in hydrogen.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/3354
- Title:
- Spectra of quasar narrow-line regions
- Short Name:
- J/MNRAS/448/3354
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a single optical spectrum, the quasar narrow-line region (NLR) reveals low density, photoionized gas in the host galaxy interstellar medium, while the immediate vicinity of the central engine generates the accretion disk continuum and broad emission lines. To isolate these two components, we construct a library of high S/N optical composite spectra created from the Sloan Digital Sky Survey (SDSS-DR7). We divide the sample into bins of continuum luminosity and H{beta} FWHM that are used to construct median composites at different redshift steps up to 0.75. We measure the luminosities of the narrow-emission lines [NeV]{lambda}3427, [NeIII]{lambda}3870, [OIII]{lambda}5007, and [OII]{lambda}3728 with ionization potentials (IPs) of 97, 40, 35, and 13.6eV respectively. The high IP lines' luminosities show no evidence of increase with redshift consistent with no evolution in the AGN SED or the host galaxy ISM illuminated by the continuum. In contrast, we find that the [OII] line becomes stronger at higher redshifts, and we interpret this as a consequence of enhanced star formation contributing to the [OII] emission in host galaxies at higher redshifts. The SFRs estimated from the [OII] luminosities show a flatter increase with z than non-AGN galaxies given our assumed AGN contribution to the [OII] luminosity. Finally, we confirm an inverse correlation between the strength of the FeII{lambda}4570 complex and both the [OIII] EW (though not the luminosity) and the width of the H{beta} line as known from the eigenvector 1 correlations.
17167. Spectra of 6 SBS stars
- ID:
- ivo://CDS.VizieR/J/A+A/532/A69
- Title:
- Spectra of 6 SBS stars
- Short Name:
- J/A+A/532/A69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Faint high latitude carbon stars are rare objects commonly thought to be distant, luminous giants. For this reason they are often used to probe the structure of the Galactic halo; however more accurate investigation of photometric and spectroscopic surveys has revealed an increasing percentage of nearby objects with luminosities of main sequence stars. We analyzed new optical spectra and photometry and used astronomical databases available on the web, aiming at clarifying the nature of the ten carbon star candidates present in the General Catalogue of the Second Byurakan Survey. We verified that two stars are N-type giants already confirmed by other surveys. We found that four candidates are M-type stars and confirmed the carbon nature of the remaining four stars; the characteristics of three of them are consistent with an early CH giant type. The fourth candidate, SBS 1310+561 identified with a high proper motion star, is a rare type of dwarf carbon showing emission lines in its optical spectrum. We estimated absolute magnitudes and distances to the dwarf carbon and the CH stars. Our limited sample confirmed the increasing evidence that spectroscopy or colour alone are not conclusive luminosity discriminants for CH-type carbon stars.
17168. Spectra of SMC star clusters
- ID:
- ivo://CDS.VizieR/J/A+A/440/111
- Title:
- Spectra of SMC star clusters
- Short Name:
- J/A+A/440/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present flux-calibrated integrated spectra in the range 360-680nm for 18 concentrated SMC clusters. The objects are part of a systematic spectroscopic survey of SMC star clusters which is being undertaken at Complejo Astronomico El Leoncito (CASLEO) in San Juan (Argentina) and Cerro Tololo Inter-American Observatory (CTIO, Chile).
- ID:
- ivo://CDS.VizieR/J/ApJ/900/11
- Title:
- Spectra of SN 2017eaw 545 & 900 days after explosion
- Short Name:
- J/ApJ/900/11
- Date:
- 14 Mar 2022 07:13:15
- Publisher:
- CDS
- Description:
- SN 2017eaw, the tenth supernova observed in NGC6946, was a normal Type II-P supernova with an estimated 11-13M{sun} red supergiant progenitor. Here we present nebular-phase spectra of SN 2017eaw at +545 and +900days post-max, extending approximately 50-400days past the epochs of previously published spectra. While the +545day spectrum is similar to spectra taken between days +400 and +493, the +900day spectrum shows dramatic changes both in spectral features and emission-line profiles. The H{alpha} emission is flat-topped and boxlike with sharp blue and red profile velocities of ~-8000 and +7500km/s. These late-time spectral changes indicate strong circumstellar interaction with a mass-loss shell, expelled ~1700yr before explosion. SN 2017eaw's +900day spectrum is similar to those seen for SN2004et and SN2013ej observed 2-3yr after explosion. We discuss the importance of late-time monitoring of bright SNeII-P and the nature of presupernova mass-loss events for SNII-P evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/414/699
- Title:
- Spectra of southern late-type dwarfs
- Short Name:
- J/A+A/414/699
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Echelle spectra of 91 late-type dwarfs, of spectral types from F to M and of different levels of chromospheric activity, obtained with the 2.15-m telescope of the CASLEO Observatory located in the Argentinean Andes. Our observations range from 3890 to 6690{AA}, at a spectral resolution from 0.141 to 0.249{AA} per pixel (R={lambda}/{delta}{lambda}~26400). The observations were flux calibrated with the aid of long slit spectra (R~1050-2070), also available.