Since 2013, we are performing with the Nancay Radio Telescope (NRT) a monitoring program of > 100 Galactic disk OH/IR stars, having bright 1612-MHz OH maser emission. The variations of the maser emission are used to probe the underlying stellar variability. We wish to understand how the large-amplitude variations are lost during the AGB – post-AGB transition. The fading out of pulsations with steadily declining amplitudes seems to be a viable process.

Using an evolutionary population synthesis code, we modeled the universal, featureless X-ray luminosity function of high-mass X-ray binaries (HMXBs) in star-forming galaxies. We put constraints on the natal kicks, super-Eddington accretion factor, as well as common envelope prescriptions usually adopted (i.e., the αCE formalism and the γ algorithm), and presented the detailed properties of HMXBs under different models, which may be investigated further by future high-resolution X-ray and optical observations.

We describe near-IR H-band VLTI-PIONIER aperture synthesis images of the carbon AGB star R Sculptoris with an angular resolution of 2.5 mas. The data show a stellar disc of diameter ∼ 9 mas exhibiting a complex substructure including one dominant bright spot with a peak intensity of 40% to 60% above the average intensity. We interpret the complex structure as caused by giant convection cells, resulting in large-scale shock fronts, and their effects on clumpy molecule and dust formation seen against the photosphere at distances of 2–3 stellar radii. Moreover, we derive fundamental parameters of R Scl, which match evolutionary tracks of initial mass 1.5 ± 0.5 M⊙. Our visibility data are best fit by a dynamic model without a wind, which may point to problems with current wind models at low mass-loss rates.

Section 4 of the FM14 focus on the outreach action and advocacy in the context of IAUs 2020-2030 Strategic Plan. This paper also contains supplementary materials that point to contributed talks and poster presentations that can be found online.

The flux distributions of spectrophotometric standard stars were initially derived from the comparison of stars to laboratory sources of known flux but are now based on calculated model atmospheres. For example, pure hydrogen white dwarf (WD) models provide the basis for the HST CALSPEC archive of flux standards. There is good evidence that relative fluxes from the visible to the near-IR wavelength of ∼2.5 μm are currently accurate to ∼1% for the primary reference standards.

This review describes where we are today in light of the dust and gas properties and their relation to star formation, in low metallicity galaxies of the local universe following recent surveys from sensitive infrared space telescopes, mainly Spitzer and Herschel space observatories as well as ground-based observations of the molecular gas reservoir. Models to interpret the ISM properties are gaining sophistication in order to account for the wide range of valuable observational diagnostics that we have today to trace the different gas phases, the broad range of photometry we have, from mid-infrared to submillimetre dust emission and the various galactic size scales that we can sample today. This review summarizes the rich multi-phase observations we can exploit today, and the multi-phase modeling approach to interpret the observations.

X-ray binaries with black hole (BH) accretors and massive star donors at short orbital periods of a few days can evolve into close binary BH (BBH) systems that merge within the Hubble time. From an observational point of view, upon the Roche-lobe overflow such systems will most likely appear as ultra-luminous X-ray sources (ULXs). To study this connection, we compute the mass transfer phase in systems with BH accretors and massive star donors (M > 15 Mʘ) at various orbital separations and metallicities. In the case of core-hydrogen and core-helium burning donors (cases A and C of mass transfer) we find the typical duration of super-Eddington mass transfer of up to 106 and 105 yr, with rates of 10−6 and 10−5Mʘ yr-1, respectively. Given that roughly 0.5 ULXs are found per unit of star formation rate, we estimate the rate of BBH mergers from stable mass transfer evolution to be at most 10 Gpc−3 yr−1.

The materials of large asteroids and asteroid families are sampled by meteorites that fall to Earth. The cosmic ray exposure age of the meteorite identifies the collision event from which that meteorite originated. The inclination of the orbit on which the meteoroid impacted Earth measures the inclination of the source region, while the semi-major axis of the orbit points to the delivery resonance, but only in a statistical sense. To isolate the sources of our meteorites requires multiple documented falls for each cosmic ray exposure peak. So far, only 36 meteorites have been recovered from observed falls. Despite these low numbers, some patterns are emerging that suggest CM chondrites originated from near the 3:1 resonance from a low-inclined source (perhaps the Sulamitis family), LL chondrites came to us from the ν6 resonance (perhaps the Flora family), there is an H chondrite source at high inclination (Phocaea?), and one group of low shock-stage L chondrites originates from the inner main belt. Other possible links are discussed.

We present the results from the abundance analysis of 21 primary stars in Sirius-like systems with various masses of white dwarf companions and orbital separation to understand the origin and nature of Ba stars. Three new Ba dwarfs are found for which masses are relatively low compared to Ba giants. Large fraction of the sample are found to be non-Ba stars, however, some of them have required WD mass and/or close orbital separation. Observed s-process abundances in Ba dwarfs are in good agreement with AGB models of respective WD companion mass, however, it required different pollution factors.

We presented long-term optical observations of the high mass X-ray binary system SS 433 (V1343 Aql) with a black hole component. New observations have been obtained by using the 0.6m telescope at the TÜBİTAK National Observatory (TUG) in B, V, R and I filters. We aim to investigate the long-term photometric behavior of the system.

We present Doppler images of the active dwarf star V1358 Ori using high-resolution spectra from the NARVAL spectropolarimeter mounted on the Bernard Lyot Telescope. The spectra were taken between 09-20 Dec, 2013 with a resolution of R=80000. Doppler imaging was carried out with our new generation multi-line Dopper imaging code iMap (Carroll et al. 2012). 40 individual photospheric lines were selected by line depth, temperature sensitivity and blends. Two data subsets were formed to get two consecutive Doppler images. Prominent cool spots at lower latitudes are found on both maps. At 0.5 phase there is a prominent equatorial feature on both maps. Weaker polar features can be seen on the first map, which somewhat diminishes for the second map. On the first image there is a cool surface feature at 30 degrees latitude which seems to fade greatly on the second map. Around 0.75 phase, a new spot seems to form. These changes suggest a rapid surface evolution. Spot displacements may also indicate surface differential rotation, which was derived by cross-correlating the two subsequent Doppler images (see e.g. Kővári et al. 2012). We fit the latitudinal correlation peaks with a sine-squared law. The fit suggests solar-type surface differential rotation with a shear parameter of α=0.02±0.02. The shear parameter fits the ${P_{{\rm{rot}}}} - |\alpha | $ diagram in Kővári et al. (2017) quite well.

The Lambda Cold Dark Matter (LCDM) paradigm makes specific predictions for the abundance, structure, substructure and clustering of dark matter halos, the sites of galaxy formation. These predictions can be directly tested, in the low-mass halo regime, by dark matter-dominated dwarf galaxies. A number of potential challenges to LCDM have been identified when confronting the expected properties of dwarfs with observation. I review our understanding of a few of these issues, including the “missing satellites” and the “too-big-to-fail” problems, and argue that neither poses an insurmountable challenge to LCDM. Solving these problems requires that most dwarf galaxies inhabit halos of similar mass, and that there is a relatively sharp minimum halo mass threshold to form luminous galaxies. These predictions are eminently falsifiable. In particular, LCDM predicts a large number of “dark” low-mass halos, some of which should have retained enough primordial gas to be detectable in deep 21 cm or Hα surveys. Detecting this predicted population of “mini-halos” would be a major discovery and a resounding success for LCDM on small scales.

Methylamine (CH3NH2) is the simplest amine and thought to be a potential interstellar precursor to the amino acid glycine (NH2CH2COOH). It is confirmed by the experimental work and in terms of exploration in the Solar system, CH3NH2 has been detected in two comets. However, in molecular clouds, a robust detection of CH3NH2 has been reported only for Sgr B2(N) so far, while a variety of complex organic molecules have been detected by radio observations in many star-forming regions. To search for CH3NH2, we used the ALMA Cycle 2 archival data toward Orion Kleinmann-Low nebula (Orion-KL) at Band 6 and found 5 candidate emission at the hot core region. By using the rotation diagram method, we evaluated its tentative column density and rotational temperature to be 4.9×10 cm−2 and 102 K, respectively.

The first visibility of the lunar crescent signals the start of a new month in the Islamic calendar. The eminent astronomer Ḥabash al-Ḥāsib sib developed a method of uncompromising complexity for predicting the visibility of the lunar crescent. He derived his threshold value from a moonwatch carried out at different places in Iraq on November 17th, 860 CE. We will allude to a few modern visibility criteria as well and highlight the uncertainties of today’s calculations when converting historical Arabic into Julian or Gregorian dates. Tables of first visibility of the lunar crescent for different locations are provided for the purpose of date conversions. Since the Islamic calendar was based on the observation of the lunar crescent, historical dates imply information on positive and negative sightings of the lunar crescent. From such information estimations of cloudiness in different regions of the Islamic world can be extracted.

Star formation is inefficient. Recent advances in numerical simulations and theoretical models of molecular clouds show that the combined effects of interstellar turbulence, magnetic fields and stellar feedback can explain the low efficiency of star formation. The star formation rate is highly sensitive to the driving mode of the turbulence. Solenoidal driving may be more important in the Central Molecular Zone, compared to more compressive driving agents in spiral-am clouds. Both theoretical and observational efforts are underway to determine the dominant driving mode of turbulence in different Galactic environments. New observations with ALMA, combined with other instruments such as CARMA, JCMT and the SMA begin to reveal the magnetic field structure of dense cores and protostellar disks, showing highly complex field geometries with ordered and turbulent field components. Such complex magnetic fields can give rise to a range of stellar masses and jet/outflow efficiencies in dense cores and protostellar accretion disks.

Classical Wolf-Rayet stars are evolved, hydrogen depleted massive stars that exhibit strong mass-loss. In theory, these stars can form either by intrinsic mass loss (stellar winds or eruptions), or via mass-removal in binaries. The Wolf-Rayet stars in the Magellanic Clouds are often thought to have originated through binary interaction due to the low ambient metallicity and, correspondingly, reduced wind mass-loss. We performed a complete spectral analysis of all known WR binaries of the nitrogen sequence in the Small and Large Magellanic Clouds, as well as additional orbital analyses, and constrained the evolutionary histories of these stars. We find that the bulk of Wolf-Rayet stars are luminous enough to be explained by single-star evolution. In contrast to prediction, we do not find clear evidence for a large population of low-luminosity Wolf-Rayet stars that could only form via binary interaction, suggesting a discrepancy between predictions and observations.

We have discovered a population of 29 outlying Hα emitters which appear like unresolved blobs in the DR14 data release of the SDSS IV MaNGA integral field unit survey. They do not have any underlying optical continuum emission in deep imaging from the DECam Legacy Survey or Beijing-Arizona Sky Survey. These blobs either lie away from the disc of the host galaxy in the MaNGA IFU and/or have velocities which are different from the velocity map of the host galaxy. Interestingly, all of them show photoionisation due to star formation. These galaxies have very high specific star formation rates compared to the known population of dwarf galaxies. However, their metallicities are consistent with or even lowerthan those of the local volume dwarfs. Thus, we can possibly rule out tidal dwarf galaxies. They could represent a new population of low mass and starbursting dwarf galaxies.

Accurate (< 10%) distances of Galactic star clusters allow a precise estimation of the physical parameters of any physically associated Planetary Nebula (PN) and also that of its central star (CSPN) and its progenitor. The progenitor’s mass can be related to the PN’s chemical characteristics and, furthermore, provides additional data for the widely used white dwarf (WD) initial-to-final mass relation (IFMR) that is crucial for tracing the development of both carbon and nitrogen in entire galaxies. To date, there is only one PN (PHR1315- 6555) confirmed to be physically associated with a Galactic open cluster (ESO 96 -SC04) that has a turn-off mass ∼2Mʘ. Our deep HST photometry was used for the search of the CSPN of this currently unique PN. In this work, we present our results.