Search Publications

Over-expansion of a coronal mass ejection generates sub-Alfvénic plasma conditions in the solar wind at Earth
DOI: 10.1051/0004-6361/202039867 Bibcode: 2021A&A...647A.149C

Schmieder, B.; Poedts, S.; Démoulin, P. +4 more

Context. From May 24-25, 2002, four spacecraft located in the solar wind at about 1 astronomical unit (au) measured plasma densities one to two orders of magnitude lower than usual. The density was so low that the flow became sub-Alfvénic for four hours, and the Alfvén Mach number was as low as 0.4. Consequently, the Earth lost its bow shock, and …

2021 Astronomy and Astrophysics
SOHO 5
Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. VII. Elder suns with low-mass companions
DOI: 10.1051/0004-6361/202037892 Bibcode: 2021A&A...648A..58N

Adamów, M.; Maciejewski, G.; Villaver, E. +3 more

Context. We present the current status of and new results from our search for exoplanets in a sample of solar-mass evolved stars observed with the HARPS-N and the 3.6 m Telescopio Nazionale Galileo (TNG), and the High-Resolution Spectrograph (HRS) and the 9.2 m Hobby-Eberly Telescope (HET).
Aims: The aim of this project is to detect and chara…

2021 Astronomy and Astrophysics
Hipparcos 5
The GRAVITY young stellar object survey. V. The orbit of the T Tauri binary star WW Cha
DOI: 10.1051/0004-6361/202039599 Bibcode: 2021A&A...648A..37G

Genzel, R.; Sturm, E.; Duchêne, G. +60 more

Context. Close young binary stars are unique laboratories for the direct measurement of pre-main-sequence (PMS) stellar masses and their comparison to evolutionary theoretical models. At the same time, a precise knowledge of their orbital parameters when still in the PMS phase offers an excellent opportunity for understanding the influence of dyna…

2021 Astronomy and Astrophysics
Gaia 5
A new search for star forming regions in the southern outer Galaxy
DOI: 10.1051/0004-6361/202039523 Bibcode: 2021A&A...645A.113K

König, C.; Menten, K. M.; Wyrowski, F. +2 more

Context. Star formation in the outer Galaxy is thought to be different from that in the inner Galaxy, as it is subject to different environmental parameters such as metallicity, interstellar radiation field, or mass surface density, which all change with galactocentric radius. Extending our star formation knowledge, from the inner to the outer Gal…

2021 Astronomy and Astrophysics
Herschel 5
Detecting the intrinsic X-ray emission from the O-type donor star and the residual accretion in a supergiant fast X-ray transient in its faintest state
DOI: 10.1051/0004-6361/202141378 Bibcode: 2021A&A...654A.131S

Salvaterra, R.; Marelli, M.; Sidoli, L. +4 more

We report on the results of an XMM-Newton observation of the supergiant fast X-ray transient (SFXT) IGR J08408-4503 performed in June 2020. The source is composed of a compact object (likely a neutron star) orbiting around an O8.5Ib-II(f)p star, LM Vel. The X-ray light curve shows a very low level of emission, punctuated by a single, faint flare. …

2021 Astronomy and Astrophysics
Gaia XMM-Newton 5
X-ray study of Abell 3365 with XMM-Newton
DOI: 10.1051/0004-6361/201937160 Bibcode: 2021A&A...646A..95U

Urdampilleta, I.; Simionescu, A.; Kaastra, J. S. +5 more

We present an X-ray spectral analysis using XMM-Newton/EPIC observations (∼100 ks) of the merging galaxy cluster Abell 3365 (z = 0.093). Previous radio observations suggested the presence of a peripheral elongated radio relic to the east and a smaller radio relic candidate to the west of the cluster center. We find evidence of temperature disconti…

2021 Astronomy and Astrophysics
XMM-Newton 5
Fine structure in the luminosity function in young stellar populations with Gaia DR2
DOI: 10.1051/0004-6361/202141205 Bibcode: 2021A&A...655A..45G

Brown, Anthony G. A.; Kaper, Lex; de Bruijne, Jos H. J. +2 more

Context. A pioneering study showed that the fine structure in the luminosity function (LF) of young star clusters contains information about the evolutionary stage (age) and composition of the stellar population. The notable features include the H-peak, which is the result of the onset of hydrogen burning turning pre-main sequence stars into main …

2021 Astronomy and Astrophysics
Gaia 5
HADES RV programme with HARPS-N at TNG. XIV. A candidate super-Earth orbiting the M-dwarf GJ 9689 with a period close to half the stellar rotation period
DOI: 10.1051/0004-6361/202141141 Bibcode: 2021A&A...651A..93M

Rebolo, R.; Ribas, I.; Morales, J. C. +27 more

Context. It is now well-established that small, rocky planets are common around low-mass stars. However, the detection of such planets is challenged by the short-term activity of host stars.
Aims: The HARPS-N red Dwarf Exoplanet Survey programme is a long-term project at the Telescopio Nazionale Galileo aimed at monitoring nearby, early-type,…

2021 Astronomy and Astrophysics
Gaia 5
Strongly lensed candidates from the HSC transient survey
DOI: 10.1051/0004-6361/202039376 Bibcode: 2021A&A...655A.114C

Suyu, Sherry H.; Jaelani, Anton T.; Nagao, Tohru +5 more

We present a lensed quasar search based on the variability of lens systems in the Hyper Suprime-Cam (HSC) transient survey. Starting from 101 353 variable objects with i-band photometry in the HSC transient survey, we used a variability-based lens search method measuring the spatial extent in difference images to select potential lensed quasar can…

2021 Astronomy and Astrophysics
eHST 5
Wide companions to M and L subdwarfs with Gaia and the Virtual Observatory
DOI: 10.1051/0004-6361/202140493 Bibcode: 2021A&A...650A.190G

Cortés-Contreras, M.; Solano, E.; Lodieu, N. +3 more


Aims: The aim of the project is to identify wide common proper motion companions to a sample of spectroscopically confirmed M and L metal-poor dwarfs (also known as subdwarfs) to investigate the impact of metallicity on the binary fraction of low-mass metal-poor binaries and to improve the determination of their metallicity from the higher-ma…

2021 Astronomy and Astrophysics
Gaia 5