Related papers: Observational Report on the Classical Nova KT Erid…
We make use of \textit{JWST} medium and broad-band NIRCam imaging, along with ultra-deep MIRI $5.6 \rm \mu m$ imaging, in the Hubble eXtreme Deep Field (XDF) to identify prominent line emitters at $z\simeq 7-8$. Out of a total of 58…
We performed optical spectroscopy and photometry of SN 2006gy at late time, ~400 days after the explosion, with the Subaru/FOCAS in a good seeing condition. We found that the SN faded by ~3 mag from ~200 to ~400 days after the explosion…
Optical (BVRI) and infrared (JHK) photometry of the gamma-ray nova Nova Sco 2012 (V1324 Sco) is presented and the lightcurve reconstructed and discussed. An interstellar reddening E(B-V)=1.23 is derived. Dust begun to form at an early date…
For decades optical time-domain searches have been tuned to find ordinary supernovae, which rise and fall in brightness over a period of weeks. Recently, supernova searches have improved their cadences and a handful of fast-evolving…
We present deep 10h VLT/XSHOOTER spectroscopy for an extraordinarily luminous and extended Lya emitter at z=6.595 referred to as Himiko and first discussed by Ouchi et al. (2009), with the purpose of constraining the mechanisms powering its…
Coronal mass ejections (CMEs) are a prominent contributor to solar system space weather and might have impacted the Sun's early angular momentum evolution. A signal diagnostic of CMEs on the Sun is coronal dimming: a drop in coronal…
We used the 6.5m MMT to obtain a spectrum of the AM CVn star CP Eri in quiescence. The spectrum is dominated by He I emission lines, which are clearly double peaked with a peak-to-peak separation of ~1900 km/s. The spectrum is similar to…
We report on multiwavelength observations of nova SMCN 2016-10a. The present observational set is one of the most comprehensive for any nova in the Small Magellanic Cloud, including: low, medium, and high resolution optical spectroscopy and…
We present X-ray observations of novae V2491 Cyg and KT Eri about 9 years post-outburst, of the dwarf nova and post-nova candidate EY Cyg, and of a VY Scl variable. The first three objects were observed with XMM-Newton, KT Eri also with the…
Nova Her 2021 (V1674 Her), which erupted on 2021 June 12, reached naked-eye brightness and has been detected from radio to $\gamma$-rays. An extremely fast optical decline of 2 magnitudes in 1.2 days and strong Ne lines imply a high-mass…
We describe and analyze Hubble Space Telescope (HST) observations of transient emission near 4680 {\AA} in Eta Car, reported earlier by Steiner & Damineli (2004). If, as seems probable, this is He II $\lambda$4687, then it is a unique clue…
We present spectrophotometry of the eclipsing old nova BT Mon (Nova Mon 1939). By detecting weak absorption features from the secondary star, we find its radial velocity semi-amplitude to be K_R = 205+/-5 km/s and its rotational velocity to…
Spectroscopically, TDEs are characterized by broad ( 10$^{4}$ km/s) emission lines and show large diversity as well as different line profiles. After carefully and consistently performing a series of data reduction tasks including host…
We present the results of spectrophotometric observations of the old nova RR Pic performed in two spectral ranges, one centered in the Ha line and other covering Hb and Hg spectral lines. From the Hb radial velocity study we found a primary…
Archival X-ray observations of EF Eridani obtained in a low state revealed distinct X-ray detections at a luminosity L_X ~ 2 10^{29} erg/s, three orders of magnitude below its high state value. The plasma temperature was found to be as low…
We present optical and near-infrared photometry, along with optical spectra, of the Type Ia supernova SN 2000E in the spiral galaxy NGC 6951. It was discovered by the staff of the Teramo Observatory during the monitoring of the SN 1999el.…
We present deep Hubble Space Telescope (HST) photometry of the ultra-faint dwarf galaxy Eridanus II (Eri II). Eri II, which has an absolute magnitude of M_V = -7.1, is located at a distance of 339 kpc, just beyond the virial radius of the…
We present a multi-color, high-cadence photometric study of a distant dwarf nova KSP-OT-201611a discovered by the Korea Microlensing Telescope Network Supernova Program. From October 2016 to May 2017, two outbursts, which comprises a…
The rising phase toward the optical maximum of a classical nova is one of the last frontiers of nova study. Constructing free-free emission model light curves based on our fully self-consistent nova explosion models, we present several…
We present a series of optical spectroscopic and near-infrared photometric observations of the Be star X Persei, from the beginning of the recent emission phase. Our data show that after the latest extended low state (ELS), both the…