A5067213493- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- X-ray Spectroscopy and Fluorescence Analysis
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Laser-Plasma Interactions and Diagnostics
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Advanced X-ray Imaging Techniques
- Photocathodes and Microchannel Plates
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Spectroscopy and Laser Applications
Liverpool John Moores University
2015-2024
We present observations and analysis of 18 stripped-envelope supernovae observed during 2013–2018. This sample consists five H/He-rich SNe, six H-poor/He-rich three narrow lined SNe Ic, four broad Ic. The peak luminosity characteristic time-scales the bolometric light curves are calculated, modelled to derive 56Ni ejecta masses (MNi Mej). Additionally, temperature evolution spectral line velocity each SN examined. Analysis [O i] in nebular phase eight suggests their progenitors had initial...
RS Ophiuchi began its latest outburst on 2006 February 12. Previous outbursts have indicated that high-velocity ejecta interact with a preexisting red giant wind, setting up shock systems analogous to those seen in supernova remnants. However, the previous 1985, X-ray observations did not commence until 55 days after initial explosion. Here we report Swift covering first month of Burst Alert Telescope (BAT) and X-Ray (XRT) instruments. Oph was clearly detected BAT 14-25 keV band from t = 0 ~...
ABSTRACT The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption 10 times, including yearly eruptions from 2008 to 2014. With a measured recurrence period of <?CDATA ${P}_{\mathrm{rec}}=351\pm 13$?> days (we believe the true value be half this) and white dwarf very close Chandrasekhar limit, has become leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations 2013 2014 eruptions, we initiated campaign ensure early...
Of the approximately 400 known Galactic classical novae, only ten of them, recurrent have been seen to erupt more than once. At least eight these recurrents are harbor evolved secondary stars, rather main sequence secondaries typical in novae. In this paper, we propose a new nova classification system, based solely on evolutionary state secondary, and not (like current schemes) properties outbursts. Using archival optical near-infrared photometric observations sample thirty quiescent novae...
Context: In late November 2013 a fifth eruption in five years of the M31 recurrent nova M31N 2008-12a was announced. Aims: this Letter we address optical lightcurve and progenitor system 2008-12a. Methods: Optical imaging data from Liverpool Telescope, La Palma, Danish 1.54m Silla, archival Hubble Space Telescope near-IR, near-UV are astrometrically photometrically analysed. Results: Photometry eruption, combined with three previous eruptions, enabled construction template light curve very...
On 2021 August 8, the recurrent nova RS Ophiuchi erupted again, after an interval of 15.5 yr. Regular monitoring by Neil Gehrels Swift Observatory began promptly, on 9.9 (0.37 day optical peak), and continued until source passed behind Sun at start November, 86 days later. Observations then restarted 197, once Oph emerged from constraint. This makes first Galactic to have been monitored throughout two eruptions. Here we investigate extensive X-ray datasets 2006 2021, as well more limited...
ABSTRACT Just 10 recurrent novae (RNe) – which erupt repeatedly on time-scales shorter than one century are known in our Galaxy. The most extreme RN (located the Andromeda galaxy), M31N 2008-12a, undergoes a nova eruption every year, and is surrounded by vast ‘super-remnant’, 134 pc extent. Simulations predict that all RNe should be similar shells, but previous searches have failed to detect them. KT Eri has recently been suggested RN, we used Condor Array Telescope image its environs...
We report the results of our statistical study POINT-AGAPE CNe catalogue. The first Sloan $r'$ and $i'$ analysis MMRD relationship in M31 is performed using resulting CN Good fits are produced to two filters. However, we unable verify $t_{15}$ for either filter. subsequent automated detection pipeline has provided us with most thorough knowledge completeness a survey to-date. In addition, large field view permitted probe outburst rate well into galactic disk, unlike previous CCD imaging...
We report Hubble Space Telescope imaging obtained 155 days after the 2006 outburst of RS Ophiuchi. detect extended emission in both [O III] λ5007 and [Ne V] λ3426 lines. In lines, remnant has a double ring structure. The east-west orientation total extent these structures (580 ± 50 AU at d = 1.6 kpc) is consistent with that expected due to expansion emitting regions imaged earlier radio wavelengths. Expansion high velocity appears have been roughly constant direction (vexp 3200 300 km s-1...
We present light curves of three classical novae (CNe; KT Eridani, V598 Puppis, V1280 Scorpii) and one recurrent nova (RS Ophiuchi) derived from data obtained by the Solar Mass Ejection Imager (SMEI) on board Coriolis satellite. SMEI provides near complete skymap coverage with precision visible-light photometry at 102 minute cadence. The these skymaps offer unprecedented temporal resolution around, especially before, maximum light, a phase eruption normally not covered ground-based...
We report Hubble Space Telescope imaging, obtained 155 and 449 days after the 2006 outburst of recurrent nova RS Ophiuchi, together with ground-based spectroscopic observations, from Observatorio Astron\'omico Nacional en San Pedro M\'artir, Baja California, M\'exico at Astrof\'isico Guillermo Haro, Cananea, Sonora, M\'exico. The observations first epoch were used as inputs to model geometry kinematic structure evolving Oph nebular remnant. find that modeled remnant comprises two distinct...
We report the results of a multi-year spectroscopic and photometric survey novae in M31 that resulted total 53 spectra 48 individual nova candidates. Two these, M31N 1995-11e 2007-11g, were revealed to be long-period Mira variables, not novae. These data double number extant for through end 2009 bring 91 with known classifications. find 75 (82%) are confirmed or likely members Fe II class, remaining 16 (18%) belonging He/N (and related) classes. numbers consistent those found Galactic no...
Another outburst of the recurrent M31 nova M31N 2008-12a was announced in late November 2013. Optical data suggest an unprecedentedly short recurrence time approximately one year. In this Letter we address X-ray properties 2008-12a. We requested Swift monitoring observations shortly after optical discovery. estimated source count rates and extracted spectra from resulting data. The corresponding ultraviolet (UV) also analysed. clearly detected as a bright supersoft (SSS) only six days...
V745 Sco is a recurrent nova, with the most recent eruption occurring in February 2014. was first observed by Swift mere 3.7 h after announcement of optical discovery, super-soft X-ray emission being detected around 4 d later and lasting for only ∼2 d, making it both fastest follow-up nova earliest switch-on yet detected. Such an early time suggests combination very high velocity outflow low ejected mass and, together effective temperature reached emission, white dwarf (>1.3 M⊙). The...
We present observations of M31LRN 2015 (MASTER OT J004207.99+405501.1), discovered in M31 January, and identified as a rare enigmatic luminous red nova (LRN). Spectroscopic photometric obtained by the Liverpool Telescope showed LRN becoming extremely it faded from its peak. Early spectra strong Hα emission that weakened over time number absorption features appeared, including Na i D Ba ii. At later times TiO bands were also seen. A search archival Hubble Space data revealed source to be...
The POINT–AGAPE (Pixel-lensing Observations with the Isaac Newton Telescope–Andromeda Galaxy Amplified Pixels Experiment) survey is an optical search for gravitational microlensing events towards Andromeda galaxy (M31). As well as microlensing, sensitive to many different classes of variable stars and transients. Here we describe automated detection selection pipeline used identify M31 classical novae (CNe) present resulting catalogue 20 CN candidates observed over three seasons. CNe are...
The Angstrom Project is using a global network of 2m-class telescopes to conduct high cadence pixel microlensing survey the bulge Andromeda Galaxy (M31), with primary aim constraining its underlying mass distribution and stellar function. Here we investigate feasibility such detect planets in M31. We estimate efficiency detecting signals for events induced by planetary systems as function planet/star ratio separation, source type background M31 surface brightness. find that Jupiter-mass or...
Determining the evolution of ejecta morphology novae provides valuable information on shaping mechanisms in operation at early stages nova outburst. Understanding such has implications for studies example proto-Planetary Nebulae. Here we perform morpho-kinematical V2491 Cyg using spectral data to determine likely structure and its relationship central system mechanisms. We use shape model different morphologies retrieve their spectra. These synthetic spectra are compared with observed most...
The reported positions of 964 suspected nova eruptions in M31 recorded through the end calendar year 2013 have been compared order to identify recurrent candidates. To pass initial screen and qualify as a candidate two or more were required be coincident within 0.1', although this criterion was relaxed 0.15' for novae discovered on early photographic patrols. A total 118 from 51 potential systems satisfied screening criterion. determine what fraction these are indeed original plates...
Abstract Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed eruption every single year. This unprecedented frequency indicates an extreme object, with a massive white dwarf and high accretion rate, which is most promising candidate for single-degenerate progenitor of Type Ia supernova known to date. The previous three eruptions have displayed remarkably homogeneous multiwavelength properties: (i) from faint peak, optical light curve declined rapidly by two...
The recurrent nova M31N 2008-12a experiences annual eruptions, contains a near-Chandrasekhar mass white dwarf, and has the largest accretion rate in any system. In this paper, we present Hubble Space Telescope (HST) WFC3/UVIS photometry of late decline 2015 eruption. We couple these new data with archival HST observations quiescent system Keck spectroscopy 2014 late-time reveals rapid to minimum luminosity state, before possible recovery / re-brightening run-up next Comparison disk models...
The Andromeda Galaxy recurrent nova M31N 2008-12a has been caught in eruption nine times. Six observed eruptions the seven years from 2008 to 2014 suggested a duty cycle of ~1 year, which makes this most rapidly recurring system known and leading single-degenerate Type Ia Supernova progenitor candidate; but no 2010 found so far. Here we present evidence supporting recovery eruption, based on archival images taken at around time. We detect pair Nov 20.52 UT, with magnitude m_R = 17.84 +/-...
The M 31 nova M31N 2008-12a was recently found to be a recurrent (RN) with recurrence time of about 1 year. This is by far the fastest scale any known RNe. Our optical monitoring programme detected predicted 2014 outburst in early October. We immediately initiated an X-ray/UV campaign Swift study multiwavelength evolution outburst. monitored daily observations for 20 days after discovery, covering entire supersoft X-ray source (SSS) phase. SSS emission around day six state lasted...