The accretion history of low-mass young stars is not smooth but shows spikes of accretion that can last from months and years to decades and centuries. Observations of young stars in outbursts can help us understand the temporal evolution of accreting stars and the interplay between the accretion disk and the stellar magnetosphere. The young late-type star V1118 Orionis was in outburst from 2005 to 2006. We followed the outburst with optical and near-infrared photometry. The X-ray emission was further probed with observations taken with XMM-Newton and Chandra during and after the outburst. In addition, we obtained mid-infrared photometry and spectroscopy with Spitzer at the peak of the outburst and in the post-outburst phase. The spectral energy distribution of V1118 Ori varied significantly over the course of the outburst. The optical flux showed the largest variations, most likely caused by enhanced emission by a hot spot. The hot spot dominated the optical and near-infrared emission at the peak of the outburst, while the disk emission dominated in the mid-infrared. The emission silicate feature in V1118 Ori is flat and does not vary in shape, but was slightly brighter at the peak of the outburst compared to the post-outburst spectrum. The X-ray flux correlated with the optical and infrared fluxes, indicating that accretion affected the magnetically active corona and the stellar magnetosphere. The thermal structure of the corona was variable with some indication of a cooling of the coronal temperature in the early phase of the outburst with a gradual return to normal values. Color-color diagrams in the optical and infrared showed variations during the outburst, with no obvious signature of reddening caused by circumstellar matter. Using Monte-Carlo realizations of star+disk+hotspot models to fit the spectral energy distributions in "quiescence" and at the peak of the outburst, we determined that the mass accretion rate varied from about 2.5x10^-7^M_{sun}_/yr to 1.0x10^-6^M_{sun}_/yr; in addition, the fractional area of the hotspot increased significantly. The multi-wavelength study of the V1118 Ori outburst helped us to understand the variations in spectral energy distributions and demonstrated the interplay between the disk and the stellar magnetosphere in a young, strongly accreting star.
We report on a detailed spectroscopic and photometric study of V1046 Orionis undertaken to resolve uncertainties about the period(s) and causes of the spectroscopic and photometric variations of this helium-strong star. We have detected the lines of the secondary star in an extensive series of photographic and electronic spectra. This eliminates any doubt about the duplicity of this star. The orbital elements we derive from our measures of these spectra confirm the unusually large orbital eccentricity, e=0.433, for the short, P=18.65612d, orbital period. The line profiles, V/R ratio of the double H{alpha} emission, residuals of the primary radial velocities from the orbital velocity curve, brightness and colour of the object, magnetic field, and radio emission of this system all vary with a period of 0.9011836d. We tentatively follow earlier investigators in interpreting this as the rotational period of the primary and summarize the evidence of the phase shifts among the different phenomena, using the accurate value of the 0.9d period, to put tight constraints on any future model of these changes. We postpone our own attempt at a quantitative modelling of the variations with the 0.9d period for a separate study.
V1162 Ori is a delta Scuti star with variable period and amplitude. To analyse data acquired in the years 1998-2000, the data were subdivided in smaller subsets to take the amplitude and period variability into account. Four different ways of subdividing the data discussed in the paper are outlined in this table 2. A database containing the observations of V1162 Ori is in preparation; it will be published in the Journal of Astronomical data (http://www.vub.ac.be/STER/JAD/jad.htm).
Virtual Observatory for Extragalactic Astrophysics
Description:
The VOXastro Data Center's TAP end point. The Table Access
Protocol (TAP) lets you execute queries against our database tables,
inspect various metadata, and upload your own data. It is thus the
VO's premier way to access public data holdings.
Tables exposed through this endpoint include: galaxyzoo, rcsed, rcsed_fibermags, rcsed_gasmet, rcsed_lines_gauss, rcsed_lines_nonpar, rcsed_lines_nonpar_reg, simard_table2, simard_table3 from the specphot schema, columns, groups, key_columns, keys, schemas, tables from the tap_schema schema, emptyobscore, obscore from the ivoa schema.
Voyager 2 Magnetometer Jupiter Resampled Heliographic (RTN) Coords
9.60 Second Data Collection
Short Name:
VG2_MAG_HG9_60S
Date:
15 Dec 2022 19:30:23
Publisher:
Planetary Data System
Description:
This collection contains Voyager 2 Jupiter encounter magnetometer
data given in Heliographic coordinates and averaged from the 60 ms
instrument sample rate to a 9.6 second resampled rate. All magnetic
field observations are measured in nanoTesla. All of the magnetic
field data are calibrated.
Voyager 1 Magnetometer Jupiter Resampled Heliographic (RTN) Coords
48.0 Second Data Collection
Short Name:
VG1_MAG_J_48S
Date:
15 Dec 2022 19:28:35
Publisher:
Planetary Data System
Description:
This collection contains calibrated magnetic field data acquired by
the Voyager 1 Low Field Magnetometer (LFM) during the Jupiter
encounter. Coverage begins in the solar wind inbound to Jupiter and
continues past the last outbound bowshock crossing. The data are in
Heliographic (RTN) coordinates and have been averaged from the 9.6
second summary data to a 48 second sample rate. All magnetic field
measurements are given in nanoTesla (nT).
Voyager 2 Magnetometer Jupiter Resampled Heliographic (RTN) Coords
1.92 Second Data Collection
Short Name:
VG2_MAG_HG1.92S
Date:
15 Dec 2022 19:27:52
Publisher:
Planetary Data System
Description:
This collection contains Voyager 2 Jupiter encounter magnetometer
data given in Heliographic coordinates and averaged from the 60 ms
instrument sample rate to a 1.92 second resampled rate. All magnetic
field observations are measured in nanoTesla. All of the magnetic
field data are calibrated.
Voyager 2 Magnetometer Jupiter Resampled Heliographic (RTN) Coords
48.0 Second Data Collection
Short Name:
VG2_MAG_J_48S
Date:
15 Dec 2022 19:25:55
Publisher:
Planetary Data System
Description:
This collection contains Voyager 2 Jupiter encounter magnetometer
data given in Heliographic coordinates and averaged from the 60 ms
instrument sample rate to a 48 second resampled rate. All magnetic
field observations are measured in nanoTesla. All of the magnetic
field data are calibrated.
Voyager 1 Magnetometer Jupiter Resampled Heliographic (RTN) Coords
9.60 Second Data Collection
Short Name:
VG1_MAG_HG9_60S
Date:
15 Dec 2022 19:25:21
Publisher:
Planetary Data System
Description:
This collection contains calibrated magnetic field data acquired by
the Voyager 1 Low Field Magnetometer (LFM) during the Jupiter
encounter. Coverage begins in the solar wind inbound to Jupiter and
continues past the last outbound bowshock crossing. The data are in
Heliographic (RTN) coordinates and have been averaged from the 1.92
second summary data to a 9.6 second sample rate. All magnetic field
measurements are given in nanoTesla (nT).
Voyager 1 Magnetometer Jupiter Resampled Heliographic (RTN) Coords
1.92 Second Data Collection
Short Name:
VG1_MAG_HG1.92S
Date:
15 Dec 2022 19:25:16
Publisher:
Planetary Data System
Description:
This collection contains calibrated magnetic field data acquired by
the Voyager 1 Low Field Magnetometer (LFM) during the Jupiter
encounter. Coverage begins in the solar wind inbound to Jupiter and
continues past the last outbound bowshock crossing. The data are in
Heliographic (RTN) coordinates and have been averaged from the 60 ms
instrument sample rate to a 1.92 second sample rate. All magnetic
field measurements are given in nanoTesla (nT).
