Research Showcase
As well as imaging, the FT team is involved in research and is pleased to involve as many FT users as possible. One extremely successful project that we have been running since 2006 is a project involving the optical monitoring of ~35 Low-Mass X-ray Binaries (LMXBs). This project was set up by Dr David Russell (Amsterdam, IAC), Professor Rob Fender (Southampton), Dr Paul Roche (FT) and Fraser Lewis (FT). We are hugely grateful for all the help we have received.
Overview of an Extensive Multi-wavelength Study of GX 339-4 during the 2010 Outburst
M. Cadolle Bel (ESAC Madrid), J. Rodriguez (Universite Paris Diderot), P. D'Avanzo (Brera, Italy), D. M. Russell (Amsterdam), J. Tomsick (UC Berkeley), S. Corbel (Universite Paris Diderot), F. Lewis (FT), F. Rahoui (Harvard), M. Buxton (Yale), P. Goldoni (Universite Paris Diderot), E. Kuulkers (ESAC Madrid)
The microquasar GX 339-4 experienced a new outburst in 2010: it was observed
simultaneously at various wavelengths from radio up to soft gamma-rays. We
focused on observations that are quasi-simultaneous with those made with the
INTEGRAL and RXTE satellites: these were collected in 2010 March-April during
our INTEGRAL Target of Opportunity program, and during some of the other
INTEGRAL observing programs with GX 339-4 in the field-of-view. X-ray
transients are extreme systems that often harbour a black hole, and are known
to emit throughout the whole electromagnetic spectrum when in outburst. The
goals of our program are to understand the evolution of the physical processes
close to the black hole and to study the connections between the accretion and
ejection. We analysed radio, NIR, optical, UV, X-ray and soft gamma-ray
observations. We studied the source evolution in detail by producing light
curves, hardness-intensity diagrams and spectra. We fitted the broadband data
with phenomenological, then physical, models to study the emission coming from
the distinct components. Based on the energy spectra, the source evolved from
the canonical hard state to the canonical soft state. The source showed X-ray
spectral variations that were correlated with changes in radio, NIR and optical
emission. The bolometric flux increased from 0.8 to 2.9*10^{-8} erg cm^{-2}
s^{-1} while the relative flux and contribution of the hot medium globally
decreased. Reprocessing in the disc was likely to be strong at the end of our
observations. The source showed a behaviour similar to that of previous
outbursts, with some small deviations in the hard X-rays parameters' evolution.
The radio, NIR and optical emission from jets was detected, and seen to fade as
the source softened. The results are discussed within the context of disc and
jet models.
A variable mid-infrared synchrotron break associated with the compact jet in GX 339-4
P. Gandhi (JAXA, Japan), A.W. Blain (Leicester), D.M. Russell (Amsterdam), P. Casella (Southampton), J. Malzac (Toulouse), S. Corbel (Universite Paris Diderot), P. D'Avanzo (Brera, Italy), F.W. Lewis (FT), S. Markoff (Amsterdam), M. Cadolle Bel (ESAC Madrid), P. Goldoni (CEA Saclay), S. Wachter (Caltech), D. Khangulyan (JAXA, Japan), A. Mainzer (JPL)
Many X-ray binaries remain undetected in the mid-infrared, a regime where
emission from their compact jets is likely to dominate. Here, we report the
detection of the black hole binary GX 339-4 with the Wide-field Infrared Survey
Explorer (WISE) during a very bright, hard accretion state in 2010. Combined
with a rich contemporaneous multiwavelength dataset, clear spectral curvature
is found in the infrared, associated with the peak flux density expected from
the compact jet. An optically-thin slope of ~-0.7 and a jet radiative power of
>6x10^{35} erg/s (d/8 kpc)^2 are measured. A ~24 h WISE light curve shows
dramatic variations in mid-infrared spectral slope on timescales at least as
short as the satellite orbital period ~95 mins. There is also significant
change during one pair of observations spaced by only 11 s. These variations
imply that the spectral break associated with the transition from self-absorbed
to optically-thin jet synchrotron radiation must be varying across the full
wavelength range of ~3-22 microns that WISE is sensitive to, and more. Based on
four-band simultaneous mid-infrared detections, the break lies at ~5x10^{13} Hz
in at least two epochs of observation, consistent with a magnetic field
B~1.5x10^4 G assuming a single-zone synchrotron emission region. The observed
variability implies that either B, or the size of the acceleration zone above
the jet base, are being modulated by factors of ~10 on relatively-short
timescales.
A late jet rebrightening revealed from multi-wavelength monitoring of the black hole candidate XTE J1752-223
D.M. Russell (Amsterdam), P.A. Curran (CEA Saclay), T. Muñoz-Darias (Brera, Italy), F. Lewis (FT), S. Motta, H. Stiele, T. Belloni (Brera, Italy), J.C.A. Miller-Jones (Curtin University, Australia), P.G. Jonker (SRON, Harvard, Nijmegen), K. O'Brien (UC Santa Barbara), J. Homan (MIT), P. Casella (Southampton), P. Gandhi (JAXA, Japan), P. Soleri (Groningen), S. Markoff (Amsterdam), D. Maitra, E. Gallo (Michigan), M. Cadolle Bel (ESAC, Madrid)
We present optical monitoring of the black hole candidate XTE J1752-223
during its 2009 - 2010 outburst and decay to quiescence. The optical light
curve can be described by an exponential decay followed by a plateau, then a
more rapid fade towards quiescence. The plateau appears to be due to an extra
component of optical emission that brightens and then fades over ~ 40 days. We
show evidence for the origin of this optical 'flare' to be the synchrotron jet
during the decaying hard state, and we identify and isolate both disc and jet
components in the spectral energy distributions. The optical flare has the same
morphology and amplitude as a contemporaneous X-ray rebrightening. This
suggests a common origin, but no firm conclusions can be made favouring or
disfavouring the jet producing the X-ray flare. The quiescent optical
magnitudes are B >= 20.6, V >= 21.1, R >= 19.5, i' >= 19.2. From the optical
outburst amplitude we estimate a likely orbital period of < 22 h. We also
present near-infrared (NIR) photometry and polarimetry and rare mid-infrared
imaging (8 - 12 microns) when the source is nearing quiescence. The fading jet
component, and possibly the companion star may contribute to the NIR flux. We
derive deep mid-IR flux upper limits and NIR linear polarization upper limits.
With the inclusion of radio data, we measure an almost flat jet spectral index
between radio and optical; F_nu ~ nu^(~ +0.05). The data favour the jet break
to optically thin emission to reside in the infrared, but may shift to
frequencies as high as the optical or UV during the peak of the flare.
Testing the jet quenching paradigm with an ultradeep observation of a steadily soft state black hole
D. M. Russell (Amsterdam),
J. C. A. Miller-Jones (ICRAR - Curtin),
T. J. Maccarone, Y. J. Yang, R. P. Fender (Southampton),
F. Lewis (Faulkes Telescope Project, Univ. of Glamorgan, Open University)
We present ultradeep radio observations with the Expanded Very Large Array of
4U 1957+11, a Galactic black hole candidate X-ray binary known to exist in a
persistent soft X-ray state. We derive a stringent upper limit of 11.4 micro-Jy
beam^-1 (3 sigma) at 5-7 GHz, which provides the most rigorous upper limit to
date on the presence of jets in a soft state black hole X-ray binary. X-ray, UV
and optical fluxes obtained within a few weeks of the radio data can be
explained by thermal emission from the disk. At this X-ray luminosity, a hard
state black hole X-ray binary that follows the established empirical
radio--X-ray correlation would be at least 330-810 times brighter at radio
frequencies, depending on the distance to 4U 1957+11. This jet quenching of >
2.5 orders of magnitude is greater than some models predict, and implies the
jets are prevented from being launched altogether in the soft state. 4U 1957+11
is also more than one order of magnitude fainter than the faintest of the
'radio-quiet' population of hard state black holes. In addition, we show that
on average, soft state stellar-mass BHs probably have fainter jets than most
active galactic nuclei in a state equivalent to the soft state. These results
have implications for the conditions required for powerful, relativistic jets
to form, and provide a new empirical constraint for time- and accretion
mode-dependent jet models, furthering our understanding of jet production and
accretion onto BHs.
Rapid variations of polarization in low-mass X-ray binaries
D.M. Russell (Amsterdam), P.G. Casella, R.P. Fender (Southampton), P. Soleri (Groningen), M.L. Pretorius (ESO, Santiago), F. Lewis (FT), M. van der Klis (Amsterdam)
Time-resolved optical and infrared polarimetric observations of black hole and neutron star lowmass X-ray binaries are presented. Data were acquired with the VLT, UKIRT and HIPPO on the AAO 1.9-m. We find that for some sources in outburst, a rapidly variable component of polarization is evident that is stronger in the redder wavebands. We attribute this to the polarimetric signature of synchrotron emission from jets in these systems, the emission of which is known to
dominate these redder bands. Such synchrotron emission from jets launched close to black holes and neutron stars can be highly linearly polarized, depending on the configuration of the magnetic field. The variability of the polarization is suggestive of a tangled and turbulent magnetic field at the location of the compact jet. For some sources the position angle of polarization is consistent with a magnetic field that is parallel to the observed radio jet. These are some of the first observational constraints of the geometry and magnetic structure at the inner regions of the outflow. We also present the first ever simultaneous optical polarization and X-ray campaign of an X-ray binary, using data taken simultaneously with HIPPO and RXTE with sub-second time resolution.
A dwarf nova in the globular cluster M13
M. Servillat (Harvard), N.A. Webb (Toulouse), F. Lewis (FT), C. Knigge (Southampton), M. van den Berg (Utrecht/Harvard), A. Dieball (Southampton) and J. Grindlay (Harvard)
Dwarf novae in globular clusters seem to be rare with only 12 detections in the 157 known Galactic globular clusters. We report the identification of a new dwarf nova in M13, the 13th dwarf nova identified in a globular cluster to date. Using the 2m Faulkes Telescope North, we conducted a search for stars in M13 that show variability over a year (2005–2006) on timescales of days and months. This led to the detection of one dwarf nova showing several outbursts. A Chandra X-ray source is coincident with this dwarf nova and shows both a spectrum and variability consistent with that
expected from a dwarf nova, thus supporting the identification. We searched for a counterpart in Hubble Space Telescope ACS/WFC archived images and found at least 11 candidates, of which we could characterize only the 7 brightest, including one with a 3 H excess and a faint blue star. The detection of one dwarf nova when more could have been expected likely indicates that our knowledge of the global Galactic population of cataclysmic variables is too limited. The proportion of dwarf novae may be lower than found in catalogs, or they may have a much smaller duty cycle in general as proposed by some population synthesis models and recent observations in the field.
The VLT-FLAMES Tarantula Survey II: R139 revealed as a massive binary system
W. D. Taylor, C. J. Evans, H. Sana, N. R. Walborn, S. E. de Mink, V. E. Stroud, A. Alvarez-Candal, R. H. Barb, J. M. Bestenlehner, A. Z. Bonanos, I. Brott, P. A. Crowther A. de Koter, K. Friedrich, G. Grafener, V. H´enault-Brunet, A. Herrero, L. Kaper, N. Langer, D. J. Lennon, J. Maız Apellaniz, N. Markova, N. Morrell, L. Monaco, and J. S. Vink
We report the discovery that R139 in 30 Doradus is a massive spectroscopic binary system. Multi-epoch optical spectroscopy of R139 was obtained as part of the VLT-FLAMES Tarantula Survey, revealing a double-lined system. The two components are of similar spectral types; the primary exhibits strong C III 4650 emission and is classified as an O6.5 Iafc supergiant, while the secondary is an O6 Iaf supergiant. The radial-velocity variations indicate a highly eccentric orbit with a period of 153.9 days. Photometry obtained with the Faulkes Telescope South shows no evidence
for significant variability within an 18 month period. The orbital solution yields lower mass limits for the components of M1 sin3 i = 78 +/- 8 M and M2 sin3 i = 66 +/-7 M . As R139 appears to be the most massive binary system known to contain two evolved Of supergiants, it will provide an excellent test for atmospheric and evolutionary models.
Isolating the jet in broadband spectra of XBs
D. M. Russell (Amsterdam), F. Lewis (FT), D. Maitra (Michigan), R.J.H. Dunn (Munich), S.
Markoff (Amsterdam), P.G. Jonker (SRON, Harvard, Nijmegen), M. Linares (MIT), V. Tudose (Netherlands Institute for Radio Astronomy)
Most accretion-powered relativistic jet sources in our Galaxy are
transient X-ray binaries (XBs). Efforts to coordinate multiwavelength
observations of these objects have improved dramatically over the last
decade. Now the challenge is to interpret broadband spectral energy
distributions (SEDs) of XBs that are well sampled in both wavelength and
time. Here we focus on the evolution of the jet in their broadband
spectra. Some of the most densely sampled broadband SEDs of a neutron
star transient (IGR J00291+5934) are used to constrain the optically
thick–thin break in the jet spectrum. For the black hole transient XTE
J1550-564, infrared – X-ray correlations, evolution of broadband spectra
and timing signatures indicate that synchrotron emission from the jet
likely dominates the X-ray power law at low luminosities during the hard state outburst decline.
Observational detection of eclipses of J5 Amalthea by the Galilean satellites
A.A. Christou (Armagh), F. Lewis, P. Roche (FT), M.G. Hidas, T.M. Brown (LCOGT, Santa Barbara)
Aims. We carried out observations of the small jovian satellite Amalthea
(J5) as it was being eclipsed by the Galilean satellites near the 2009 equinox of Jupiter
in order to apply the technique of mutual event photometry to the astrometric
determination of this satellite’s position.
Methods. The observations were carried out during the period
06/2009−09/2009 from the island of Maui, Hawaii and Siding Spring, Australia with the 2m
Faulkes Telescopes North and South respectively. We observed in the near-infrared part of
the spectrum using a PanStarrs-Z filter with Jupiter near the edge of the field in order
to mitigate against the glare from the planet. Frames were acquired at rates
> 1/min during eclipse times predicted using
recent JPL ephemerides for the satellites. Following subtraction of the sky background
from these frames, differential aperture photometry was carried out on Amalthea and a
nearby field star.
Results. We have obtained three lightcurves which show a clear drop in
the flux from Amalthea, indicating that an eclipse took place as predicted. These were
model-fitted to yield best estimates of the time of maximum flux drop and the impact
parameter. These are consistent with Amalthea’s ephemeris but indicate that Amalthea is
slightly ahead of, and closer to Jupiter than, its predicted position by approximately
half the ephemeris uncertainty in these directions. We argue that a ground-based campaign
of higher-cadence photometry accurate at the 5% level or better during the next season of
eclipses in 2014-15 should yield positions to within 0″̣05 and affect a corresponding
improvement in Amalthea’s ephemeris.
Quiescent limits of GRO J1655-40 & XTE J1550-564
by D. E. Calvelo (Southampton), R. P. Fender (Southampton), D. M. Russell (Amsterdam), E. Gallo (UC Santa Barbara, MIT), S. Corbel (Paris), A. K. Tzioumis (Australia Telescope National Facility), M. E. Bell (Southampton), F. Lewis (FT), T. J. Maccarone (Southampton)
We present the results of radio observations of the black hole binaries GRO J1655-40 and XTE J1550-564 in quiescence, with the upgraded Australia Telescope Compact Array. Neither system was detected. Radio flux density upper limits (3 sigma) of 26 micro Jy (at 5.5 GHz), 47 micro Jy (at 9 GHz) for GRO J1655-40, and 1.4 mJy (at 1.75 GHz), 27 micro Jy (at 5.5 GHz), 47 micro Jy (at 9 GHz) for XTE J1550-564 were measured. In conjunction with quasi-simultaneous Chandra X-ray observations (in the case of GRO J1655-40) and Faulkes Telescope optical observations (XTE J1550-564) we find that these systems provide the first evidence of relatively `radio quiet' black hole binaries at low luminosities; indicating that the scatter observed in the hard state X-ray:radio correlation at higher luminosities may also extend towards quiescent levels.
The Double-Peaked 2008 Outburst of the Accreting Milli-Second X-ray Pulsar, IGR J00291+5934
by F.Lewis (FT), D.M.Russell (Amsterdam), P.G.Jonker (SRON, Harvard, Nijmegen), M.Linares (Amsterdam, MIT), V.Tudose (Netherlands Institute for Radio Astronomy), P.Roche (FT), J.S.Clark (Open), M.A.P.Torres (Harvard), D.Maitra (Amsterdam, Michigan), C.G.Bassa (Jodrell Bank), D.Steeghs (Harvard, Warwick), A.Patruno (Amsterdam), S.Migliari (ESAC), R.Wijnands (Amsterdam), G.Nelemans (Nijmegen), L.J.Kewley (Hawaii), V.E.Stroud (FT), M.Modjaz (Hawaii, Berkeley), J.S.Bloom (Berkeley), C.H.Blake (Harvard), D.Starr (Berkeley, LCOGT)
In August 2008, the accreting milli-second X-ray pulsar (AMXP), IGR J00291+5934, underwent an outburst lasting ~ 100 days, the first since its discovery in 2004. We present data from the double-peaked outburst from Faulkes Telescope North, the INT, the Keck Telescope, PAIRITEL, the Westerbork Synthesis Radio Telescope and the Swift, XMM-Newton and RXTE X-ray missions. We study the outburst's evolution at various wavelengths. We study the light curve morphology, presenting the first radio-X-ray Spectral Energy Distributions (SEDs) for this source and the most detailed UV-IR SEDs for any outbursting AMXP. We show simple models that attempt to identify the emission mechanisms responsible. We analyse short-timescale optical variability, and compare a medium resolution optical spectrum with those from 2004. The outburst morphology is unusual for an AMXP, comprising two peaks, the second containing a 'plateau' of ~ 10 days at maximum brightness within 30 days of the initial activity. This has implications on duty cycles of short-period X-ray transients. The X-ray spectrum can be fitted by a single, hard power-law. We detect optical variability of ~ 0.05 magnitudes, on timescales of minutes, but find no periodic modulation. In the optical, the SEDs contain a blue component, indicative of an irradiated disc, and a transient near-infrared (NIR) excess. This excess is consistent with a simple model of an optically thick synchrotron jet (as seen in other outbursting AMXPs). The optical spectrum shows a double-peaked H alpha profile, a diagnostic of an accretion disc, but we do not clearly see other lines (e.g. He I, II) reported in 2004. Optical/IR observations of AMXPs are excellent for studying the evolution of both the outer accretion disc and the inner jet, and may eventually provide us with tight constraints to model disc-jet coupling in accreting neutron stars.
A Long-term optical X-ray correlation in 4U 1957+11
by D.M. Russell (Amsterdam), F. Lewis, P. Roche (FT), J.S. Clark (Open University), E. Breedt, R.P. Fender (Southampton)
We present three years of optical monitoring with the Faulkes Telescopes of the Low-Mass X-ray Binary, 4U 1957+11. We see long-term variations which are correlated with X-ray flux as measured by the RXTE satellite's ASM instrument.
The VLT-FLAMES Tarantula Survey
by Chris Evans (UK ATC, Royal Observatory, Edinburgh) et al.
The Tarantula Survey is an ambitious ESO Large Programme that has obtained multi-epoch spectroscopy of over 1,000 massive stars in the 30 Doradus region of the Large Magellanic Cloud. Here we introduce the scienti c motivations of the survey and give an overview of the observational sample. Ultimately, quantitative analysis of every star, paying particular attention to the effects of rotational mixing and binarity, will be used to address fundamental questions in both stellar and cluster evolution.
CCD BV Photometry of three southern galactic open clusters using Faulkes Telescope South
A paper to be published in the August issue of the British Astronomical Association (BAA) Journal by David Boyd along with staff and students of Kennet School, Thatcham.
Jupiter - IAU Circular 9055
A. A. Christou, Armagh Observatory, reports that his CCD photometry of Jupiter V (Amalthea), obtained by F. Lewis (Faulkes Telescope Project, Open University) using the 2-m Faulkes Telescope South (+ Pan-STARRS z' filter) reveals an eclipse of this satellite by Jupiter I (Io) on June 23 UT. Twenty-five 5-sec exposures were acquired between June 23.64799 and 23.66425. Amalthea was visible in all these frames with the exception of those starting at June 23.65317 and 23.65379 UT, consistent with a totality between June 23.65292 and 23.65401 predicted by utilizing a generic mutual- eclipse model (Christou 2005, Icarus 178, 171) in combination with the SPICE ephemeris kernel JUP230 for the Galilean satellites and Amalthea. Observations at high cadence (<< 60 s) of further eclipses of Amalthea by Io are encouraged during the current Jovian equinox season. Predictions for July and August 2009 are given here
Robotic Astronomy with the Faulkes Telescopes and Las Cumbres Observatory Global Telescope
by F. Lewis (FT), R. Street (LCOGT), P. Roche, V. Stroud (FT), D.M. Russell (Amsterdam)
submitted to the 'Robotic Astronomy' issue of 'Advances in Astronomy'
We present results from ongoing science projects conducted by members of the Faulkes Telescope (FT) team and Las Cumbres Observatory Global Telescope (LCOGT). Many of these projects incorporate observations carried out and analysed by FT users, comprising amateur astronomers and schools.
We also discuss plans for the further development of the LCOGT network.
The Faulkes Telescope Project: Not Just Pretty Pictures
by F. Lewis (FT), P. Roche (FT)
published in ".Astronomy: Networked Astronomy and the New Media", 2009, edited by R.J. Simpson, D. Ward-Thompson
The Faulkes Telescope (FT) Project is an educational and research arm of the Las Cumbres Observatory Global Telescope Network (LCOGTN). As well as producing spectacular images of galaxies, nebulae, supernovae remnants, star clusters, etc., the FT team is involved in several projects pursuing scientific goals. Many of these projects also incorporate data collected and analysed by schools and amateur astronomers.
Astrometric observations of the Uranian satellites with the Faulkes Telescope North in 2007 September
by M.Y. Khovritchev (Central Astronomical Observatory of Russian Academy of Science)
published in MNRAS, 2009, 393, 1353-1358
Observational detection of eight mutual eclipses and occultations between the satellites of Uranus
by A. A. Christou (Armagh Observatory), F. Lewis (FT), P. Roche(FT), Y. Hashimoto (SAAO, SALT), D. O’Donoghue (SAAO), H. Worters (SAAO, SALT), D. A. H. Buckley (SAAO, SALT), T. Michalowski (Poznan), D. J. Asher (Armagh), A. Bitsaki (Athens), A. Psalidas (Patras), V. Tsamis (Athens), K. N. Gourgouliatos (Cambridge), A. Liakos (Athens), M. G. Hidas (LCOGT), T. M. Brown (LCOGT)
Published in Astronomy and Astrophysics (A&A)
Social Networking: An astronomer's field guide
by Gomez, E.L., Gomez H.L., Yardley, J.
published in ".astronomy: Networked Astronomy and the New Media", 2009, edited by R.J. Simpson, D. Ward-Thompson
We present a brief introduction to the phenomenon of "social networking" and its potentially powerful use as an astronomy outreach and educational tool. We briefly discuss the development of applications for websites and Facebook, and the use of web trackers such as Google Analytics to analyze the audience. Finally we discuss how social bookmarking can be used to promote work to unexpected audiences.
Optical spectroscopy and photometry of SAX J1808.4-3658 in outburst
by P. Elebert (Cork), M. T. Reynolds (Michigan), P. J. Callanan (Cork), D. J. Hurley (Cork), G. Ramsay (Armagh), F. Lewis (FT), D. M. Russell (Amsterdam), B. Nord (Michigan), S. R. Kane (Caltech), D. L. DePoy (Texas A&M), P. Hakala (Turku)
published in MNRAS
An observation of a mutual event between two satellites of Uranus
by M.G. Hidas (LCOGT), A.A. Christou (Armagh), T.M. Brown (LCOGT)
published in MNRAS, 2008, 384, L38-L40
We present observations of the occultation of Umbriel by Oberon on 2007 May 4. We believe this is the first observed mutual event between satellites of Uranus. Fitting a simple geometric model to the light curve, we measure the mid-event time with a precision of 4 s. We assume previously measured values for the albedos of the two satellites, and measure the impact parameter to be 500 +/- 80 km. These measurements are more precise than estimates based on current ephemerides for these satellites. Therefore observations of additional mutual events during the 2007-2008 Uranian equinox will provide improved estimates of their orbital and physical parameters.
Unifying disc-jet behaviour in X-ray binaries: an optical/IR approach
by D.M. Russell (Amsterdam), D. Maitra (Amsterdam), R.P. Fender (Southampton), F. Lewis (FT)
published in Proceedings of the 7th Microquasar Workshop: Microquasars and Beyond, September 2008, Foca, Turkey
Continued Monitoring of LMXBs with the Faulkes Telescopes
by F. Lewis (FT) D.M. Russell (Amsterdam), R.P. Fender (Southampton), Paul Roche (FT), J.S. Clark (Open University)
published in Proceedings of the 7th Microquasar Workshop: Microquasars and Beyond, September 2008, Foca, Turkey
The nature of the close magnetic white dwarf + probable brown dwarf binary SDSS J121209.31+013627.7
by M.R. Burleigh (Leicester), T.R. Marsh (Warwick), B.T. Gänsicke (Warwick), M.R. Goad (Leicester), V.S. Dhillon (Sheffield), S.P. Littlefair (Sheffield), M.Wells (Oundle School), N.P. Bannister, C.P. Hurkett, A. Martindale, P.D. Dobbie, S.L. Casewell, D.E.A. Baker, J. Duke (Leicester), J. Farihi (Gemini Observatory), M.J. Irwin (Cambridge), P.C. Hewett (Cambridge), P. Roche (FT), F. Lewis (FT)
FT Team members have also been involved in the following Astronomer's Telegrams (ATels)
3622 D. M. Russell (Amsterdam), F. Lewis, (Univ. of Glamorgan, Faulkes Telescope Project,
Open Univ.), D. Altamirano (Amsterdam), P. Roche (Univ. of
Glamorgan, Faulkes Telescope Project, Open Univ.)
The optical counterpart of the accreting millisecond X-ray pulsar IGR J17498-2921
3517 D. M. Russell (Amsterdam), F. Lewis, (Univ. of Glamorgan, Faulkes Telescope Project,
Open Univ.), L. Schreuder, Y.J. Yang, R. Wijnands, (Amsterdam), A. Tripp (Faulkes Telescope Project)
MAXI J1659-152 fading in optical
3383 D. M. Russell
(University of Amsterdam), J. Homan, J. K. Fridriksson (MIT), F. Lewis,
P. Roche (Univ. of Glamorgan, Faulkes Telescope Project, Open Univ.), C.
O'Morain (Univ. of Glamorgan)
GX 339-4 is back in a faint state close to quiescence
3359 David M. Russell (Univ. of Amsterdam), Fraser Lewis, Paul Roche (Faulkes Telescope Project, Open Univ., Univ. of Glamorgan) Diego Altimarano (Univ. of Amsterdam)
Candidate optical counterparts of MAXI J1543-564
3191 David M. Russell (Univ. of Amsterdam), Fraser Lewis (Faulkes Telescope Project, Open Univ., Univ. of Glamorgan)
GX 339-4 back in the hard state: optical observations reveal the return of the jet
3116 David M. Russell (Univ. of Amsterdam), Fraser Lewis (Faulkes Telescope Project, Open Univ., Univ. of Glamorgan), Rosa Doran (EU-Hands on Universe), Sarah Roberts (Faulkes Telescope Project, Univ. of Glamorgan)
Optical observations of MAXI J0556-332 and an indication of a probable neutron star primary
2997 D. M. Russell, Y. J. Yang, N. Degenaar, R. Wijnands, A. Patruno, R. Kaur, M. Armas Padilla (Univ. of Amsterdam), F. Lewis (Faulkes Telescope Project, Open Univ., Univ. of Glamorgan), J. D. Armstrong (Univ. of Hawai'i)
Monitoring of the likely optical counterpart of XTE J1728-295
2884 D. M. Russell (Univ. of Amsterdam), F. Lewis (Faulkes Telescope Project, Open Univ., Univ. of Glamorgan), D. Bersier and Z. Cano (Liverpool JMU), P. Gandhi (ISAS, Japan Aerospace Exploration Agency), A. Patruno, M. Kalamkar, Y. J. Yang, D. Altamirano (Univ. of Amsterdam), P. Casella (Univ. of Southampton), M. Linares (MIT), M. Armas Padilla, Y. Cavecchi, N. Degenaar, R. Kaur, M. van der Klis, A. Watts and R. Wijnands (Univ. of Amsterdam), N. Rea (CSIC-IEEC)
Optical variability in MAXI J1659-152
2871 D. M. Russell (Univ. of Amsterdam), P. Roche, F. Lewis (Faulkes Telescope Project, Open Univ., Univ. of Glamorgan), D. Maitra (Univ. of Michigan)
Aql X-1 in brightest outburst since 2003
2827 D. M. Russell, Y. J. Yang, A. Patruno, N. Degenaar, D. Altamirano, R. Wijnands (University of Amsterdam), F. Lewis (FT)
Candidate optical counterparts of XTE J1728-295 = IGR J17285-2922
2775 Russell, D. (Amsterdam), Munoz-Darias, T. (Brera), Lewis, F. (FT), Soleri, P. (Groningen)
XTE J1752-233 has faded to quiescence; optical and infrared magnitudes
2722 Armas Padilla, M., Kaur, R., Degenaar, N., Wijnands, R. (Amsterdam), Lewis, F., Russell, D. M.(Amsterdam)
Re-brightening of XMMSL1 J171900.4-353217
2579 Y.J. Yang, D.M. Russell, R. Wijnands, M. van der Klis, D. Altamirano, A. Patruno, A. Watts , M. Armas Padilla, Y. Cavecchi, N. Degenaar, M. Kalamkar, R. Kaur (University of Amsterdam), M. Linares (MIT), P. Casella (Southampton), N. Rea (IEEC-CSIC), P. Soleri (Groningen), F. Lewis (Faulkes Telescope Project, University of Glamorgan) and A.K.H. Kong (NTHU, Taiwan)
SWIFT J1749.4-2807: X-ray decay, refined position and optical observation
2573 M. Cadolle Bel, E. Kuulkers, A. Ibarra, M. Diaz Trigo (ESAC Madrid, Spain), J. Tomsick (SSL/UC Berkeley, USA), J. Rodriguez, L. Prat, S. Corbel (CEA-AIM Saclay, France), D.M. Russell, D. Altamirano (University of Amsterdam), F. Lewis (Faulkes Telescope Project, University of Glamorgan, Open University), E. Bozzo, M. Turler, C. Ferrigno (ISDC, Geneva)
Simultaneous INTEGRAL, RXTE, Swift and FT South observations of the transition of GX 339-4
2547 D.M. Russell (Amsterdam), M. Buxton (Yale), F. Lewis (FT), D. Altamirano (Amsterdam)
Optical/IR flux fading rapidly in GX 339-4: OIR jet quenching
2467 E. Del Monte, R. Campana, I. Donnarumma, Y. Evangelista, M. Feroci (Rome), D. Altamirano, D.M. Russell (Amsterdam), P. Casella (Southampton), E. Kuulkers, C. Sanchez-Fernandez (ESA/ESAC), F. Lewis (FT), J.J.M. in't Zand (SRON, Netherlands)
Spectral transition of 4U 1608-522 during the undergoing 2010 outburst
2459 F. Lewis (FT), D.M. Russell (Amsterdam), M. Cadolle Bel (ESA/ESAC)
Optical Observations of GX 339-4 in Outburst with the Faulkes Telescope South
2288 M. Linares (MIT), J. Miller-Jones (NRAO), D. Altamirano (Amsterdam), G. Sivakoff (Virginia), D. Maitra, D.M. Russell (Amsterdam), F. Lewis (FT), C. Markwardt (U. Maryland & NASA/GSFC), R. Remillard (MIT) and the JACPOT XRB collaboration
Aql X-1 back in outburst: multi-wavelength observations
2270 F. Lewis (FT), D.M. Russell (Amsterdam)
GX 339-4 Approaching Quiescence ?
2072 D.M. Russell (Amsterdam), F. Lewis (FT), P.Roche (FT)
X-ray state change in 4U 1608-52
2000 V. Tudose (Netherlands Institute for Radio Astronomy - ASTRON), Z. Paragi (Joint Institute for Very Long Baseline Interferometry in Europe - JIVE), P. Soleri, D.M. Russell, D. Maitra (Amsterdam), F. Lewis (FT), R.P. Fender (Southampton), M.A. Garrett (ASTRON), R.E. Spencer, A. Rushton (Jodrell Bank)
e-EVN observations of Aql X-1 in outburst
1970 D.M. Russell (Amsterdam), F. Lewis (FT)
Optical and hard X-ray detections of an outburst from Aquila X-1
1962 D.M. Russell (Amsterdam), F. Lewis (FT), P.Casella (Amsterdam), M.L. Pretorius (SAAO), R.P. Fender (Southampton), P. Roche (FT), J.S. Clark (Open University)
Optical photometry and polarimetry of GX 339-4 during its outburst rise
1765 F. Lewis (FT), D.M. Russell (Amsterdam), N. Rea (Amsterdam), P. Roche (FT), J. S. Clark (OU)
Recent optical variability in LSI +61 303
1726 F. Lewis (FT), M. Linares (Amsterdam), D.M. Russell (Amsterdam), R. Wijnands (Amsterdam), P. Roche (FT)
Renewed optical and X-ray activity in IGR J00291+5934
1666 D. M. Russell (Amsterdam), F. Lewis (FT), M. Linares (Amsterdam), P. Roche (FT), D. Maitra (Amsterdam)
Faulkes Telescope monitoring of the current outburst of IGR J00291+5934
1586 D.M. Russell (Amsterdam), D. Altamirano (Amsterdam), F. Lewis (FT), P. Roche (FT), C.B. Markwardt (CRESST/GSFC/UMD), R.P. Fender (Southampton)
Unusual optical and X-ray flaring activity in GX 339-4
1218 D. Maitra (Amsterdam), D.M. Russell (Amsterdam), F. Lewis (FT), C. Bailyn (Yale), R.P Fender (Southampton), P. Roche (FT)
Optical and Near-IR Observations of the Current Outburst of Aql X-1
