scholarly journals The Optical Transient Search in the Bamberg Southern Sky Survey: Preliminary Results

10.14311/1502 ◽  
2012 ◽  
Vol 52 (1) ◽  
Author(s):  
R. Hudec ◽  
F. Kopel ◽  
P. Krapp ◽  
U. Heber ◽  
W. Cayé
Keyword(s):  
High School ◽  
Gamma Ray ◽  
Large Fraction ◽  
Gamma Ray Bursts ◽  
Extended Study ◽  
Maximum Light ◽  
Sky Survey ◽  
Optical Transients ◽  
Optical Surveys ◽  
Optical Transient

A large fraction of gamma-ray bursts temporarily emit optical light, i.e. optical afterglows and optical transients. So far, optical transients have only been detected after related gamma-ray satellite detection. However, taking into account their optical magnitudes at maximum light, these objects should be detectable in various historical and recent optical surveys, including the photographic sky patrol. Here we report on an extended study based on blink-comparison of 5004 Bamberg Observatory Southern Sky Patrol Plates performed within a student high school project (Jugend Forscht).

scholarly journals Master Robotic Net

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Vladimir Lipunov ◽  
Victor Kornilov ◽  
Evgeny Gorbovskoy ◽  
Nikolaj Shatskij ◽  
Dmitry Kuvshinov ◽  
...  
Keyword(s):  
Dark Energy ◽  
Solar System ◽  
Gamma Ray ◽  
Optical Emission ◽  
Gamma Ray Bursts ◽  
Sky Survey ◽  
Single Night

The main goal of the MASTER-Net project is to produce a unique fast sky survey with all sky observed over a single night down to a limiting magnitude of 19-20. Such a survey will make it possible to address a number of fundamental problems: search for dark energy via the discovery and photometry of supernovae (including SNIa), search for exoplanets, microlensing effects, discovery of minor bodies in the Solar System, and space-junk monitoring. All MASTER telescopes can be guided by alerts, and we plan to observe prompt optical emission from gamma-ray bursts synchronously in several filters and in several polarization planes.

scholarly journals The Zadko Telescope: A Southern Hemisphere Telescope for Optical Transient Searches, Multi-Messenger Astronomy and Education

2010 ◽  
Vol 27 (3) ◽  
pp. 331-339 ◽  
Author(s):  
D. M. Coward ◽  
M. Todd ◽  
T. P. Vaalsta ◽  
M. Laas-Bourez ◽  
A. Klotz ◽  
...  
Keyword(s):  
East Coast ◽  
Gamma Ray ◽  
High Energy ◽  
Pilot Program ◽  
Public Outreach ◽  
Southern Latitude ◽  
Optical Transients ◽  
Robotic Telescope ◽  
Optical Transient ◽  
Potential Tool

AbstractThe new 1 m f/4 fast-slew Zadko Telescope was installed in June 2008 about 70 km north of Perth, Western Australia. It is the only metre-class optical facility at this southern latitude between the east coast of Australia and South Africa, and can rapidly image optical transients at a longitude not monitored by other similar facilities. We report on first imaging tests of a pilot program of minor planet searches, and Target of Opportunity observations triggered by the Swift satellite. In 12 months, 6 gamma-ray burst afterglows were detected, with estimated magnitudes; two of them, GRB 090205 (z = 4.65) and GRB 090516 (z = 4.11), are among the most distant optical transients imaged by an Australian telescope. Many asteroids were observed in a systematic 3-month search. In September 2009, an automatic telescope control system was installed, which will be used to link the facility to a global robotic telescope network; future targets will include fast optical transients triggered by high-energy satellites, radio transient detections, and LIGO gravitational wave candidate events. We also outline the importance of the facility as a potential tool for education, training, and public outreach.

scholarly journals Searching for Gravitationally Lensed Gamma-Ray Bursts with Their Afterglows

2022 ◽  
Vol 924 (2) ◽  
pp. 49
Author(s):  
Shengnan Chen ◽  
Xudong Wen ◽  
He Gao ◽  
Kai Liao ◽  
Liangduan Liu ◽  
...  
Keyword(s):  
Time Delay ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Archival Data ◽  
Potential Candidate ◽  
X Ray ◽  
Gamma Ray Detectors ◽  
Sky Survey ◽  
Lensing Effect ◽  
Recent Claim

Abstract Gamma-ray bursts (GRBs) at high redshifts are expected to be gravitationally lensed by objects of different mass scales. Other than a single recent claim, no lensed GRB has been detected so far by using gamma-ray data only. In this paper, we suggest that multiband afterglow data might be an efficient way to search for lensed GRB events. Using the standard afterglow model, we calculate the characteristics of the lensed afterglow lightcurves under the assumption of two popular analytic lens models: the point-mass and singular isothermal sphere models. In particular, when different lensed images cannot be resolved, their signals would be superimposed together with a given time delay. In this case, the X-ray afterglows are likely to contain several X-ray flares of similar width in linear scale and similar spectrum, and the optical afterglow lightcurve will show re-brightening signatures. Since the lightcurves from the image arriving later would be compressed and deformed in the logarithmic timescale, the larger time delay (i.e., the larger mass of the lens), the easier it is to identify the lensing effect. We analyzed the archival data of optical afterglows and found one potential candidate of the lensed GRB (130831A) with time delay ∼500 s; however, observations of this event in gamma-ray and X-ray bands seem not to support the lensing hypothesis. In the future, with the cooperation of the all-sky monitoring gamma-ray detectors and multiband sky survey projects, the method proposed in this paper would be more efficient in searching for strongly lensed GRBs.

scholarly journals X-ray plateaus in gamma-ray bursts’ light curves from jets viewed slightly off-axis

2020 ◽  
Vol 492 (2) ◽  
pp. 2847-2857 ◽  
Author(s):  
Paz Beniamini ◽  
Raphaël Duque ◽  
Frédéric Daigne ◽  
Robert Mochkovitch
Keyword(s):  
Gamma Ray ◽  
Large Fraction ◽  
Gamma Ray Bursts ◽  
Point Of View ◽  
Light Curves ◽  
Late Time ◽  
X Ray ◽  
Narrow Region ◽  
Central Engine ◽  
Γ Rays

ABSTRACT Using multiple observational arguments, recent work has shown that cosmological gamma-ray bursts (GRBs) are typically viewed at angles within, or close to the cores of their relativistic jets. One of those arguments relied on the lack of tens-of-days-long periods of very shallow evolution that would be seen in the afterglow light curves of GRBs viewed at large angles. Motivated by these results, we consider that GRBs efficiently produce γ-rays only within a narrow region around the core. We show that, on these near-core lines of sight, structured jets naturally produce shallow phases in the X-ray afterglow of GRBs. These plateaus would be seen by a large fraction of observers and would last between 102–105 s. They naturally reproduce the observed distributions of time-scales and luminosities as well as the intercorrelations between plateau duration, plateau luminosity, and prompt γ-ray energy. An advantage of this interpretation is that it involves no late-time energy injection which would be both challenging from the point of view of the central engine and, as we show here, less natural given the observed correlations between plateau and prompt properties.

scholarly journals Revealing Short GRB Jet Structure and Dynamics with Gravitational Wave Electromagnetic Counterparts

2017 ◽  
Vol 13 (S338) ◽  
pp. 1-8
Author(s):  
Gavin P. Lamb ◽  
Shiho Kobayashi
Keyword(s):  
Gravitational Wave ◽  
Gamma Ray ◽  
Compact Object ◽  
Gamma Ray Bursts ◽  
Viewing Angle ◽  
Hidden Population ◽  
Structure And Dynamics ◽  
Optical Transients ◽  
Jet Structure

AbstractCompact object mergers are promising candidates for the progenitor system of short gamma-ray bursts (GRBs). Using gravitational wave (GW) triggers to identify a merger, any electromagnetic (EM) counterparts from the jet can be used to constrain the dynamics and structure of short GRB jets. GW triggered searches could reveal a hidden population of optical transients associated with the short-lived jets from the merger object. If the population of merger-jets is dominated by low-Lorentz-factors, then a GW triggered search will reveal the on-axis orphan afterglows from these failed GRBs. By considering the EM counterparts from a jet, with or without the prompt GRB, the jet structure and dynamics can be constrained. By modelling the afterglow of various jet structures with viewing angle, we provide observable predictions for the on- and off- axis EM jet counterparts. The predictions provide an indication for the various features expected from the proposed jet structure models.

scholarly journals RIBOTS: An Automatic Telescope System for Gamma-Ray Burst Follow-Up Observations

2001 ◽  
Vol 183 ◽  
pp. 155-156
Author(s):  
Yuji Urata ◽  
Nobuyuki Kawai ◽  
Atsumasa Yoshida ◽  
Mitsuhiro Kohama ◽  
Tetsuya Kawabata ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Observation System ◽  
Alert System ◽  
Gamma Ray Burst ◽  
Fully Automatic ◽  
Optical Flashes ◽  
Optical Transient ◽  
Telescope System

AbstractWe are constructing a fully automatic observation system named RIBOTS (RIken-Bisei Optical Transient Seeker). We aim to detect optical flashes and early afterglows of Gamma-ray bursts (GRB) with RIBOTS. We are constructing RIBOTS with a small telescope because a quick pointing to the burst is essential for our purpose. RIBOTS is linked to the GRB alert system provided by the HETE-2 satellite.

scholarly journals Exploring nine simultaneously occurring transients on April 12th 1950

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beatriz Villarroel ◽  
Geoffrey W. Marcy ◽  
Stefan Geier ◽  
Alina Streblyanska ◽  
Enrique Solano ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Photographic Plate ◽  
Gamma Ray Bursts ◽  
Point Sources ◽  
Radio Bursts ◽  
Dwarf Stars ◽  
Detection Rates ◽  
Photographic Images ◽  
Sky Survey ◽  
Ccd Detectors

AbstractNine point sources appeared within half an hour on a region within $$\sim $$ ∼ 10 arcmin of a red-sensitive photographic plate taken in April 1950 as part of the historic Palomar Sky Survey. All nine sources are absent on both previous and later photographic images, and absent in modern surveys with CCD detectors which go several magnitudes deeper. We present deep CCD images with the 10.4-m Gran Telescopio Canarias, reaching brightness $$r \sim 26$$ r ∼ 26 mag, that reveal possible optical counterparts, although these counterparts could equally well be just chance projections. The incidence of transients in the investigated photographic plate is far higher than expected from known detection rates of optical counterparts to e.g. flaring dwarf stars, Fast Radio Bursts, Gamma Ray Bursts or microlensing events. One possible explanation is that the plates have been subjected to an unknown type of contamination producing mainly point sources with of varying intensities along with some mechanism of concentration within a radius of $$\sim $$ ∼ 10 arcmin on the plate. If contamination as an explanation can be fully excluded, another possibility is fast (t $$<0.5$$ < 0.5 s) solar reflections from objects near geosynchronous orbits. An alternative route to confirm the latter scenario is by looking for images from the First Palomar Sky Survey where multiple transients follow a line.

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