Publications (67)
He II 4686 emission from the massive binary system in Car: constraints to the orbital elements and the nature of the periodic minima
M. Teodoro, A. Damineli, B. Heathcote +27
η Carinae is an extremely massive binary system in which rapid spectrum variations occur near periastron. Most notably, near periastron the He II line increases rapidly i…
A Possible Detection of Occultation by a Proto-planetary Clump in GM Cephei
The YETI Collaboration, W. P. Chen, S. C. -L. Hu +41
GM Cep in the young (~4 Myr) open cluster Trumpler 37 has been known to be an abrupt variable and to have a circumstellar disk with very active accretion. Our monitoring observatio…
First firm spectral classification of an early-B pre-main-sequence star: B275 in M17
B. B. Ochsendorf, L. E. Ellerbroek, R. Chini +4
The optical to near-infrared (300 - 2500 nm) spectrum of the candidate massive Young Stellar Object (YSO) B275, embedded in the star forming region M17, has been observed with X-sh…
A new look into putative duplicity and pulsations of the Be star CMi
P. Harmanec, M. Svanda, D. Korcakova +6
Bright Be star beta CMi has been identified as a non-radial pulsator on the basis of space photometry with the MOST satellite and also as a single-line spectroscopic binary with a…
The broad line region and dust torus structure of the Seyfert 1 WPVS48
C. Sobrino Figaredo, F. Pozo Nuñez, M. Ramolla +5
Optical and near-mid-infrared reverberation mapping data obtained at Universitätssternwarte Bochum in Chile and with the Spitzer Space Telescope allow us to explore the geometry o…
Improved Variable Star Search in Large Photometric Data Sets -- New Variables in CoRoT Field LRa02 Detected by BEST II
T. Fruth, P. Kabath, J. Cabrera +10
The CoRoT field LRa02 has been observed with the Berlin Exoplanet Search Telescope II (BEST II) during the southern summer 2007/2008. A first analysis of stellar variability led to…
The reddest ISO-2MASS quasar
C. Leipski, M. Haas, R. Siebenmorgen +9
In the course of the NIR/MIR AGN search combining the 6.7 mu ISOCAM Parallel Survey and 2MASS we have discovered 24 type-1 quasars about a third of which are too red to be discrimi…
A Survey for High-Mass Eclipsing Binaries
F. Pozo Nuñez, R. Chini, A. Barr DomÃnguez +5
We report results from a search for Galactic high-mass eclipsing binaries. The photometric monitoring campaign was performed in Sloan and with the robotic twin refractor Ro…
Near- and mid-infrared photometry of high-redshift 3CR sources
M. Haas, S. V. P. Willner, F. Heymann +5
Using the Spitzer Space Telescope, we have obtained 3.6--24 micron photometry of 38 radio galaxies and 24 quasars from the 3CR catalog at redshift 1<z<2.5. This 178 MHz-selected sa…
Double-peaked Ca II traces a relativistic broad-line region disk in NGC 4593
M. W. Ochmann, P. M. Weilbacher, M. A. Probst +7
Double-peaked emission lines are observed in a small percentage of active galactic nuclei (AGN). These lines allow the determination of properties of the line-emitting region, know…
New visual companions of solar-type stars within 25 pc
R. Chini, K. Fuhrmann, A. Barr DomÃnguez +3
We report the discovery of faint common-proper-motion companions to the nearby southern solar-type stars HD43162, HD67199, HD114837, HD114853, HD129502, HD165185, HD197214, and HD2…
A near-infrared survey of the entire R Corona Australis cloud
M. Haas, F. Heymann, I. Domke +3
To understand low- to intermediate-mass star-formation in the nearby R CrA molecular cloud, we try to identify the stellar content that is accessible with near-infrared observation…
The ISO-2MASS AGN survey: On the type-1 sources
C. Leipski, M. Haas, H. Meusinger +9
We combined the ISOCAM Parallel Mode Survey at 6.7 micron (LW2 filter) with the Two Micron All Sky Survey in order to obtain a powerful tool to search for AGN independent of dust e…
Size and disk-like shape of the broad-line region of ESO399-IG20
F. Pozo Nuñez, C. Westhues, M. Ramolla +6
We present photometric reverberation mapping of the narrow-line Seyfert 1 galaxy ESO399-IG20 performed with the robotic 15 cm telescope VYSOS-6 at the Cerro Armazones Observatory.…
Probing the centre of the large circumstellar disc in M17
M. Nielbock, R. Chini, V. H. Hoffmeister +3
We investigated the nature of the hitherto unresolved elliptical infrared emission in the centre of the ~20000 AU disc silhouette in M 17. We combined high-resolution JHKsL'M' band…
The variable stellar wind of Rigel probed at high spatial and spectral resolution
O. Chesneau, A. Kaufer, O. Stahl +5
We present a spatially resolved, high-spectral resolution (R=12000) K-band temporal monitoring of Rigel using AMBER at the VLTI. Rigel was observed in the Bracket Gamma line and it…
The Bochum Survey of the Southern Galactic Disk: II. Follow-up measurements and multi-filter photometry for 1323 square degrees monitored in 2010-2015
M. Hackstein, Ch. Fein, M. Haas +8
This paper is the second in a series describing the southern Galactic Disk Survey (GDS) performed at the Universitätssternwarte Bochum near Cerro Armazones in Chile. Haas et al. (…
Optical continuum photometric reverberation mapping of the Seyfert-1 galaxy Mrk509
F. Pozo Nuñez, N. Gianniotis, J. Blex +6
We present the results of a two year optical continuum photometric reverberation mapping campaign carried out on the nucleus of the Seyfert-1 galaxy Mrk509. Specially designed narr…
Investigation of a transiting planet candidate in Trumpler 37: an astrophysical false positive eclipsing spectroscopic binary star
R. Errmann, G. Torres, T. O. B. Schmidt +50
We report our investigation of the first transiting planet candidate from the YETI project in the young (~4 Myr old) open cluster Trumpler 37. The transit-like signal detected in t…
Dust in 3CR radio galaxies: On the FR1-FR2 difference
S. A. H. Mueller, M. Haas, R. Siebenmorgen +4
We compare three 3CR samples of 11 FR1 galaxies, 17 FR2 galaxies and 18 lobe-dominated quasars contained in the ISO Data Archive. In contrast to the powerful FR2 galaxies with edge…
HD 152246 - a new high-mass triple system and its basic properties
A. Nasseri, R. Chini, P. Harmanec +6
Analyses of multi-epoch, high-resolution (R ~ 50.000) optical spectra of the O-type star HD 152246 (O9 IV according to the most recent classification), complemented by a limited nu…
The Araucaria Project: Improving the cosmic distance scale
The Araucaria Project, :, G. PietrzyÅski +21
The book consists of a number of short articles that present achievements of the Araucaria members, collaborators, and friends, in various aspects of distance determinations and re…
The Berlin Exoplanet Search Telescope II Catalog of Variable Stars. II. Characterization of the CoRoT SRc02 field
P. Klagyivik, Sz. Csizmadia, T. Pasternacki +10
Time-series photometry of the CoRoT field SRc02 was obtained by the Berlin Exoplanet Search Telescope II (BEST II) in 2009. The main aim was the ground based follow-up of the CoRoT…
The Multiplicity of High-Mass Stars
R. Chini, A. Barr, L. S. Buda +5
We report about an ongoing photometric and spectroscopic monitoring survey of about 250 O- and 540 B-type stars in the southern Milky Way with the aim to determine the fraction of…
Multi-wavelength observations of IGR J17544-2619 from quiescence to outburst
E. Bozzo, V. Bhalerao, P. Pradhan +12
In this paper we report on a long multi-wavelength observational campaign of the supergiant fast X-ray transient prototype IGR J17544-2619. A 150 ks-long observation was carried ou…
Dust emission from 3C radio galaxies and quasars: New ISO observations favour the unified scheme
K. Meisenheimer, M. Haas, S. A. H. Müller +3
In order to test the unified scheme for luminous radio galaxies and quasars we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at infrared wavelengths between 5…
2.3 micron CO emission and absorption from young high-mass stars in M17
V. H. Hoffmeister, R. Chini, C. M. Scheyda +3
We are studying the extremely young cluster of M17 to investigate the birth of high-mass stars and the initial mass function. Deep JHKL imaging and K-band spectroscopy from the VLT…
Transit Search from Antarctica and Chile - Comparison and Combination
T. Fruth, J. Cabrera, Sz. Csizmadia +17
Observing sites at the East-Antarctic plateau are considered to provide exceptional conditions for astronomy. The aim of this work is to assess its potential for detecting transiti…
A spectroscopic survey on the multiplicity of high-mass stars
R. Chini, V. H. Hoffmeister, A. Nasseri +2
The formation of stars above about twenty solar masses and their apparently high multiplicity remain heavily debated subjects in astrophysics. We have performed a vast high-resolut…
Cosmic ray contributions from rapidly rotating stellar mass black holes: Cosmic Ray GeV to EeV proton and anti-proton sources
M. L. Allen, P. L. Biermann, A. Chieffi +12
In Radio Super Novae (RSNe) a magnetic field of is observed; these are the same numbers for Blue Supe…
The progenitor of the FUor-type young eruptive star 2MASS J06593158-0405277
Ã. Kóspál, P. Ãbrahám, A. Moór +3
Only a dozen confirmed FU Orionis-type young outbursting stars (FUors) are known today; this explains the interest in the recent FUor eruption of 2MASS J06593158-0405277. Its outbu…
Zooming into the large circumstellar disk in M 17
M. Nielbock, R. Chini, V. H. Hoffmeister +3
This paper has been withdrawn by the authors.
The nearby eclipsing stellar system delta Velorum. II. First reliable orbit for the eclipsing pair
T. Pribulla, A. Merand, P. Kervella +8
Context. The nearby multiple system delta Velorum contains a widely detached eclipsing binary and a third component. Aims. We take advantage of this system offering the opportunity…
The ISOPHOT-MAMBO survey of 3CR radio sources: Further evidence for the unified schemes
M. Haas, S. A. H. Mueller, F. Bertoldi +9
We present the complete set of ISOPHOT observations of 3CR radio galaxies and quasars, which are contained in the ISO Data Archive, providing 75 mid- and far-infrared spectral ener…
Dust reverberation-mapping of the Seyfert 1 galaxy WPVS48
F. Pozo Nuñez, M. Haas, R. Chini +7
Using robotic telescopes of the Universitatssternwarte Bochum near Cerro Armazones in Chile, we monitored the z=0.0377 Seyfert 1 galaxy WPVS48 (2MASX J09594263-3112581) in the opti…
Photometric AGN reverberation mapping - an efficient tool for BLR sizes, black hole masses and host-subtracted AGN luminosities
M. Haas, R. Chini, M. Ramolla +5
Photometric reverberation mapping employs a wide bandpass to measure the AGN continuum variations and a suitable band, usually a narrow band (NB), to trace the echo of an emission…
Circumstellar Disks revealed by / Flux Variation Gradients
F. Pozo Nuñez, M. Haas, R. Chini +2
The variability of young stellar objects (YSO) changes their brightness and color preventing a proper classification in traditional color-color and color magnitude diagrams. We hav…
Unveiling the nature of IGR J17177-3656 with X-ray, NIR and Radio observations
A. Paizis, M. A. Nowak, J. Wilms +6
We report on the first broad-band (1-200 keV) simultaneous Chandra-INTEGRAL observations of the recently discovered hard X-ray transient IGR J17177-3656 that took place on 2011, Ma…
X-ray and Near Infrared observations of the obscured accreting pulsar IGR J18179-1621
M. A. Nowak, A. Paizis, J. Rodriguez +6
IGR J18179-1621 is an obscured accreting X-ray pulsar discovered by INTEGRAL on 2012 February 29. We report on our 20 ksec Chandra-High Energy Transmission Gratings Spectrometer ob…
The stellar content of the young open cluster Trumpler 37
R. Errmann, R. Neuhäuser, L. Marschall +21
With an apparent cluster diameter of 1.5° and an age of ~4 Myr, Trumpler 37 is an ideal target for photometric monitoring of young stars as well as for the search of planetary tra…
Ground-based transit observations of the HAT-P-18, HAT-P-19, HAT-P-27/WASP-40 and WASP-21 systems
M. Seeliger, M. Kitze, R. Errmann +46
As part of our ongoing effort to investigate transit timing variations (TTVs) of known exoplanets, we monitored transits of the four exoplanets HAT-P-18b, HAT-P-19b, HAT-P-27b/WASP…
Infrared to millimetre photometry of ultra-luminous IR galaxies: new evidence favouring a 3-stage dust model
U. Klaas, M. Haas, S. A. H. Mueller +7
Infrared to millimetre spectral energy distributions have been obtained for 41 bright ultra-luminous infrared galaxies. The observations were carried out with ISOPHOT between 10 an…
Narrow-line AGN in the ISO-2MASS Survey
C. Leipski, M. Haas, H. Meusinger +9
Context: A long-standing challenge of observational AGN research is to find type 2 quasars, the luminous analogues of Seyfert-2 galaxies. Aims: We search for luminous narrow-line t…
Mid-infrared spectroscopy of high-redshift 3CRR sources
C. Leipski, M. Haas, S. P. Willner +9
Using the Spitzer Space Telescope, we have obtained rest frame 9-16mu spectra of 11 quasars and 9 radio galaxies from the 3CRR catalog at redshifts 1.0<z<1.4. This complete flux-li…
Variability survey in the CoRoT SRa01 field: Implications of eclipsing binary distribution on cluster formation in NGC 2264
P. Klagyivik, Sz. Csizmadia, T. Pasternacki +11
Time-series photometry of the CoRoT field SRa01 was carried out with the Berlin Exoplanet Search Telescope II (BEST II) in 2008/2009. A total of 1,161 variable stars were detected,…
The eclipsing binary TY CrA revisited: What near-IR light curves tell us
M. Vanko, M. Ammler-von Eiff, T. Pribulla +3
New photometric observations of the hierarchical eclipsing TY CrA system were taken in the optical with VYSOS6 and in the near-IR with SOFI and REMIR. They are the first observatio…
Finding the elusive RR Lyrae companions via speckle imaging
R. Salinas, V. Kalari, G. Hajdu +25
Despite their key role in astrophysics, the binary properties of RR Lyrae stars (RRL) remain almost completely unknown since only a single RRL is confirmed as belonging to a binary…
Galaxy overdensities around 3C radio galaxies and quasars at revealed by Spitzer m and Pan-STARRS
Z. Ghaffari, Ch. Westhues, M. Haas +4
Luminous radio sources are thought to lie in galaxy clusters or proto-clusters. The complete sample of 64 high-redshift 3C sources at has been mapped with the Spitzer Spa…
The bimodal initial mass function in the Orion Nebula Cloud
H. Drass, M. Haas, R. Chini +5
Due to its youth, proximity and richness the Orion Nebula Cloud (ONC) is an ideal testbed to obtain a comprehensive view on the Initial Mass Function (IMF) down to the planetary ma…
Star formation in z>1 3CR host galaxies as seen by Herschel
P. Podigachoski, P. D. Barthel, M. Haas +15
We present Herschel (PACS and SPIRE) far-infrared (FIR) photometry of a complete sample of z>1 3CR sources, from the Herschel GT project The Herschel Legacy of distant radio-loud A…
Reddening maps of the Magellanic Clouds using spectral energy distribution fitting of red giants
H. Netzel, G. PietrzyÅski, M. Górski +9
Robust reddening maps of the Large and Small Magellanic Clouds (LMC/SMC) are crucial for a wide range of astrophysical studies, including the calibration of the cosmic distance lad…
Photometric reverberation mapping of 3C120
F. Pozo Nuñez, M. Ramolla, C. Westhues +5
We present the results of a five month monitoring campaign of the local active galactic nuclei (AGN) 3C120. Observations with a median sampling of two days were conducted with the…
The Berlin Exoplanet Search Telescope II. Catalog of Variable Stars. I. Characterization of Three Southern Target Fields
T. Fruth, J. Cabrera, R. Chini +11
A photometric survey of three Southern target fields with BEST II yielded the detection of 2,406 previously unknown variable stars and an additional 617 stars with suspected variab…
Eclipsing high-mass binaries I. Light curves and system parameters for CPD-518946, PISMIS24-1 and HD319702
A. Barr DomÃnguez, R. Chini, F. Pozo Nuñez +5
We present first results of a comprehensive photometric O-star survey performed with a robotic twin refractor at the Universitätssternwarte Bochum located near Cerro Armazones in…
V1294 Aql = HD 184279: A bad boy among Be stars or an important clue to the Be phenomenon?
P. Harmanec, H. BožiÄ, P. Koubský +21
A reliable determination of the basic physical properties and variability patterns of hot emission-line stars is important for understanding the Be phenomenon and ultimately, the e…
Towards a consistent model of the hot quadruple system HD 93206 = QZ Carinae - I. Observations and their initial analyses
P. Harmanec, P. Zasche, M. Brož +17
The hot nine-component system HD 93206, which contains a gravitationally bounded eclipsing Ac1+Ac2 binary (~d) and a spectroscopic Aa1+Aa2 (~d) binary can provi…
A two-step strategy to identify episodic sources of gravitational waves and high energy neutrinos in starburst galaxies
M. L. Allen, P. L. Biermann, L. I. Caramete +12
Supermassive black hole mergers with spin-flips accelerate energetic particles through their precessing relativistic jets, producing high energy neutrinos and finally gravitational…
Towards a consistent model of the hot quadruple system HD 93206 = QZ Carinæ: II. N-body model
M. Brož, P. Harmanec, P. Zasche +16
HD 93206 is early-type massive stellar system, composed of components resolved by direct imaging (Ab, Ad, B, C, D) as well as a compact sub-system (Aa1, Aa2, Ac1, Ac2). Its geometr…
Light curves of the latest FUor: Indication of a close binary
M. Hackstein, M. Haas, Ã. Kóspál +11
We monitored the recent FUor 2MASS J06593158-0405277 (V960 Mon) since November 2009 at various observatories and multiple wavelengths. After the outburst by nearly 2.9 mag in a…
The broad-line region and dust torus size of the Seyfert 1 galaxy PGC50427
F. Pozo Nuñez, M. Ramolla, C. Westhues +10
We present the results of a three years monitoring campaigns of the type-1 active galactic nucleus (AGN) PGC50427. Through the use of Photometric Reverberation Mapping…
Dust emissivity in the Submm/Mm: SCUBA and SIMBA observations of Barnard 68
S. Bianchi, J. Goncalves, M. Albrecht +4
We have observed the dark cloud Barnard 68 with SCUBA at 850 um and with SIMBA at 1.2 mm. The submillimetre and millimetre dust emission correlate well with the extinction map of A…
Modelling photometric reverberation data -- a disk-like broad-line region and a potentially larger black hole mass for 3C120
F. Pozo Nuñez, M. Haas, M. Ramolla +7
We consider photometric reverberation mapping, where the nuclear continuum variations are monitored via a broad-band filter and the echo of emission line clouds of the broad line r…
The transient event in NGC 1566 from 2017 to 2019 -- I. An eccentric accretion disk and a turbulent, disk-dominated broad-line region unveiled by double-peaked Ca II and O I lines
M. W. Ochmann, W. Kollatschny, M. A. Probst +12
NGC 1566 is known for exhibiting recurrent outbursts, which are accompanied by changes in spectral type. The most recent transient event occurred from 2017 to 2019 and was reported…
Young Exoplanet Transit Initiative (YETI)
R. Neuhäuser, R. Errmann, A. Berndt +80
We present the Young Exoplanet Transit Initiative (YETI), in which we use several 0.2 to 2.6m telescopes around the world to monitor continuously young (< 100 Myr), nearby (< 1 kpc…
Periodic variable stars in CoRoT field LRa02 observed with BEST II
P. Kabath, A. Erikson, H. Rauer +8
The Berlin Exoplanet Search Telescope II (BEST II) is a small wide field-of-view photometric survey telescope system located at the Observatorio Cerro Armazones, Chile. The high du…
Is there a compact companion orbiting the late O-type binary star HD 164816?
L. Trepl, V. V. Hambaryan, T. Pribulla +7
We present a multi-wavelength (X-ray, -ray, optical and radio) study of HD 194816, a late O-type X-ray detected spectroscopic binary. X-ray spectra are analyzed and the X-ray p…
The Morphology of M17-UC1 - A Disk Candidate Surrounding a Hypercompact HII Region
M. Nielbock, R. Chini, V. H. Hoffmeister +4
We investigate the morphology and the evolutionary stage of the hypercompact HII region M17-UC1 using observations at infrared wavelengths and NIR radiative transfer modeling. For…