Related papers: Eruptive Variable Stars and Outflows in Serpens NW

Be stars have generally been characterized by the emission lines in their spectra, and especially the time variability of those spectroscopic features. They are known to also exhibit photometric variability at multiple timescales, but have…

The VISTA Variables in the Via Lactea (VVV) survey obtained near-infrared photometry toward the Galactic bulge and the southern disc plane for a decade (2010 - 2019). We designed a modified Lomb-Scargle method to search for large-amplitude…

The variability of fast-rotating Oe/Be stars has been reported in detail in recent years. However, much less known about the behaviour of fast-rotating OB stars without known decretion disks, and hence it is difficult to identify the…

Many aspects of the evolutionary phase in which Asymptotic Giant Branch stars (AGB stars) are in transition to become Planetary Nebulae (PNe) are still poorly understood. An important question is how the circumstellar envelopes of AGB stars…

A historical problem for indirect exoplanet detection has been contending with the intrinsic variability of the host star. If the variability is periodic, it can easily mimic various exoplanet signatures, such as radial velocity variations…

We present images and spectra of the Cepheus E (Cep E) region at both optical and infrared wavelengths. Only the brightest region of the southern lobe of the Cep E outflow reveals optical emission, suggesting that the extinction close to…

Theoretical models suggest that massive stars form via disk-mediated accretion, with bipolar outflows playing a fundamental role. A recent study toward massive molecular outflows has revealed a decrease of the SiO line intensity as the…

The VVV survey has allowed for an unprecedented number of multi-epoch observations of the southern Galactic plane. In a recent paper,13 massive young stellar objects(MYSOs) have already been identified within the highly variable(\Delta Ks >…

The Young Stellar Object (YSO) W33A is one of the best known examples of a massive star still in the process of forming. Here we present Gemini North ALTAIR/NIFS laser-guide star adaptive-optics assisted K-band integral-field spectroscopy…

EC53 is an embedded protostar with quasi-periodic emission in the near-IR and sub-mm. We use ALMA high-resolution observations of continuum and molecular line emission to describe the circumstellar environment of EC 53. The continuum image…

We present an analysis of 17 years of Fermi-LAT observations of the microquasar SS~433. We detect four GeV sources in the region: a newly identified source, PS J1910+0550, located outside W50; the previously reported source J1913+0512; and…

We present the first results from a 124 night J, H, K near-infrared monitoring campaign of the dark cloud L 1003 in Cygnus OB7, an active star-forming region. Using 3 seasons of UKIRT observations spanning 1.5 years, we obtained…

We present time-series photometric and spectroscopic data for seven old novae. They are used to derive the orbital period for the systems V365 Car (5.35 h), AR Cir (5.14 h), V972 Oph (6.75 h), HS Pup (6.41 h), V373 Sct (3.69 h), V909 Sgr…

We present new observations of the fundamental ro-vibrational CO spectrum of V1647 Ori, the young star whose recent outburst illuminated McNeil's Nebula. Previous spectra, acquired during outburst in 2004 February and July, had shown the CO…

We present photometric study of NY Ser, an in-the-gap SU UMa-type nova, in 2002 and 2013. We determined the duration of the superoutburst and the mean superhump period to be 18 d and 0.10458 d, respectively. We detected in 2013 that NY Ser…

We have conducted multi-epoch EVN observations of the 22.2 GHz water masers towards four high-mass star forming regions (Sh 2-255 IR, IRAS 23139+5939, WB89-234, and OMC2). The (three) observing epochs span a time range of 6 months. In each…

We present Spitzer IRAC images that indicate the presence of cavities cut into the dense outer envelope surrounding very young pre-main sequence stars. These young stellar objects (YSOs) characterized by an outflow represent the earliest…

We present observations towards a high-mass ($\rm >40\,M_{\odot}$), low luminosity ($\rm <10\,L_{\odot}$) $\rm 70\,\mu$m dark molecular core G 28.34 S-A at 3.4 mm, using the IRAM 30 m telescope and the NOEMA interferometer. We report the…

We present the X-ray images of all the available Chandra observations of the galactic jet source SS 433. We have studied the morphology of the X-ray images and inspected the evolution of the arcsec X-ray jets, recently found to be…

EX Lup-type objects (EXors) are low-mass pre-main sequence objects characterized by outbursts attributed to highly enhanced disk accretion. The trigger mechanism of EXor outbursts is still debated. One theory requires a close (sub)stellar…