Peak X-ray Flux Research Articles

Ionospheric response to X-class solar flares in the ascending half of the subdued solar cycle 24

The signature of 11 X-class solar flares that occurred during the ascending half of the present subdued solar cycle 24 from 2009 to 2013 on the ionosphere over the low- and mid-latitude station, Dibrugarh (27.5∘N, 95∘E; magnetic latitude 17.6∘N), are examined. Total electron content (TEC) data derived from Global Positioning System satellite transmissions are used to study the effect of the flares on the ionosphere. A nonlinear significant correlation (R 2 = 0.86) has been observed between EUV enhancement (ΔEUV) and corresponding enhancement in TEC (ΔTEC). This nonlinearity is triggered by a rapid increase in ΔTEC beyond the threshold value ∼1.5 (×1010 ph cm−2 s−1) in ΔEUV. It is also found that this nonlinear relationship between TEC and EUV flux is driven by a similar nonlinear relationship between flare induced enhancement in X-ray and EUV fluxes. The local time of occurrence of the flares determines the magnitude of enhancement in TEC for flares originating from nearly similar longitudes on the solar disc, and hence proximity to the central meridian alone may not play the dominating role. Further, the X-ray peak flux, when corrected for the earth zenith angle effect, did not improve the correlation between ΔX-ray and ΔTEC.

Solar flares, coronal mass ejections and solar energetic particle event characteristics

A new catalogue of 314 solar energetic particle (SEP) events extending over a large time span from 1984 to 2013 has been compiled. The properties as well as the associations of these SEP events with their parent solar sources have been thoroughly examined. The properties of the events include the proton peak integral flux and the fluence for energies above 10, 30, 60 and 100 MeV. The associated solar events were parametrized by solar flare (SF) and coronal mass ejection (CME) characteristics, as well as related radio emissions. In particular, for SFs: the soft X-ray (SXR) peak flux, the SXR fluence, the heliographic location, the rise time and the duration were exploited; for CMEs the plane-of-sky velocity as well as the angular width were utilized. For radio emissions, type III, II and IV radio bursts were identified. Furthermore, we utilized element abundances of Fe and O. We found evidence that most of the SEP events in our catalogue do not conform to a simple two-class paradigm, with the 73% of them exhibiting both type III and type II radio bursts, and that a continuum of event properties is present. Although, the so-called hybrid or mixed events are found to be present in our catalogue, it was not possible to attribute each SEP event to a mixed/hybrid sub-category. Moreover, it appears that the start of the type III burst most often precedes the maximum of the SF and thus falls within the impulsive phase of the associated SF. At the same time, type III bursts take place within ≈5.22 min, on average, in advance from the time of maximum of the derivative of the SXR flux (Neupert effect ). We further performed a statistical analysis and a mapping of the logarithm of the proton peak flux at E > 10 MeV, on different pairs of the parent solar source characteristics. This revealed correlations in 3-D space and demonstrated that the gradual SEP events that stem from the central part of the visible solar disk constitute a significant radiation risk. The velocity of the associated CMEs, as well as the SXR peak flux and fluence, are all fairly significantly correlated to both the proton peak flux and the fluence of the SEP events in our catalogue. The strongest correlation to SEP characteristics is manifested by the CME velocity.

A survey of stellar X-ray flares from theXMM-Newtonserendipitous source catalogue: HIPPARCOS-Tycho cool stars

The X-ray emission from flares on cool (i.e. spectral-type F-M) stars is indicative of very energetic, transient phenomena, associated with energy release via magnetic reconnection. We present a uniform, large-scale survey of X-ray flare emission. The XMM-Newton Serendipitous Source Catalogue and its associated data products provide an excellent basis for a comprehensive and sensitive survey of stellar flares - both from targeted active stars and from those observed serendipitously in the half-degree diameter field-of-view of each observation. The 2XMM Catalogue and the associated time-series (`light-curve') data products have been used as the basis for a survey of X-ray flares from cool stars in the Hipparcos Tycho-2 catalogue. In addition, we have generated and analysed spectrally-resolved (i.e. hardness-ratio), X-ray light-curves. Where available, we have compared XMM OM UV/optical data with the X-ray light-curves. Our sample contains ~130 flares with well-observed profiles; they originate from ~70 stars. The flares range in duration from ~1e3 to ~1e4 s, have peak X-ray fluxes from ~1e-13 to ~1e-11 erg/cm2/s, peak X-ray luminosities from ~1e29 to ~1e32 erg/s, and X-ray energy output from ~1e32 to ~1e35 erg. Most of the ~30 serendipitously-observed stars have little previously reported information. The hardness-ratio plots clearly illustrate the spectral (and hence inferred temperature) variations characteristic of many flares, and provide an easily accessible overview of the data. We present flare frequency distributions from both target and serendipitous observations. The latter provide an unbiased (with respect to stellar activity) study of flare energetics; in addition, they allow us to predict numbers of stellar flares that may be detected in future X-ray wide-field surveys. The serendipitous sample demonstrates the need for care when calculating flaring rates.

Preliminary Results of Solar Flare Induced D-Region Perturbations over UKM Using Stanford AWESOME Receiver

We present the preliminary results of VLF signal perturbations produced due to solar flare. The data were recorded by the Stanford VLF AWESOME receiver located at National University of Ma-laysia, Selangor. Two new long distance (>1000 km) VLF paths, JJI-UKM (2700 km) and NWC-UKM (3300 km) were analyzed simultaneously. Data from the GOES satellite were used to determine the onset time and type of each of these flares. Results indicated that all five solar flare events with an X-ray peak flux above 10-5 W/m2 (M-class) were recorded, 37.5% for X-ray flux greater than 10-6 W/m2 (C-class), while the weakest X-ray flux recorded was 2.6 × 10-7 W/m2 (B-class) with 0.24% probing potentiality. We found a strong positive correlation (0.84) between solar flare radiation intensity and the values of amplitude and phase perturbations for both paths. The values of amplitude and phase perturbations time-correlated with solar flare, varied from 0.2 to 5 dB and 0.15 to 20 degree respectively. These findings are in complete agreement with previous works and demonstrate that the data obtained by the UKM AWESOME observation station will provide addi-tional contribution to the study of ELF/VLF waves phenomena in the ionosphere/magnetosphere, especially at low latitudes region.

Solar flares induced D-region ionospheric and geomagnetic perturbations

The D-region ionospheric perturbations caused by solar flares which occurred during January 2010–February 2011, a low solar activity period of current solar cycle 24, have been examined on NWC transmitter signal (19.8kHz) recorded at an Indian low latitude station, Allahabad (Geographic lat. 25.75°N, long. 81.85°E). A total of 41 solar flares, including 21 C-class, 19 M-class and 01 X-class, occurred during the daylight part of the NWC-Allahabad transmitter receiver great circle path. The local time dependence of solar flare effects on the change in the VLF amplitude, time delay between VLF peak amplitude and X-ray flux peak have been studied during morning, noon and evening periods of local daytime. Using the Long Wave Propagation Capability code V 2.1 the D-region reference height (H/) and sharpness factor (β) for each class of solar flare (C, M and X) have been estimated. It is found that D-region ionospheric parameters (H/, β) strongly depend on the local time of flare's occurrence and their classes. The flare time electron density estimated by using H/ and β shows maximum increase in the electron density of the order of ~80 times as compared to the normal day values. The electron density was found to increase exponentially with increase in the solar flux intensity. The solar flare effect on horizontal component (H) of the Earth's magnetic field over an equatorial station, Tirunelveli (Geographic lat., 8.7°N, long., 77.8°E, dip lat., 0.4°N), shows a maximum increase in H of ~8.5% for M class solar flares. The increase in H is due to the additional magnetic field produced by the ionospheric electrojet over the equatorial station.

Major solar eruptions and high-energy particle events during solar cycle 24

We report on a study of all major solar eruptions that occurred on the front-side of the Sun during the rise to peak phase of cycle 24 (first 62 months) in order to understand the key factors affecting the occurrence of large solar energetic particle events (SEPs) and the ground levels enhancement (GLE) events. The eruptions involve major flares with soft X-ray peak flux >/= 5.0 x10-5 Wm-2 (i.e., flare size >/= M5.0) and accompanying coronal mass ejections (CMEs). The selection criterion was based on the fact that the only front-side GLE in cycle 24 (GLE 71) had a flare size of M5.1. Only ~37% of the major eruptions from the western hemisphere resulted in large SEP events. Almost the same number of large SEP events was produced in weaker eruptions (flare size <M5.0), suggesting that the soft X-ray flare is not a good indicator of SEP or GLE events. On the other hand, the CME speed is a better indicator of SEP and GLE events because it is consistently high supporting the shock acceleration mechanism for SEPs and GLEs. We found the CME speed, magnetic connectivity to Earth, and ambient conditions as the main factors that contribute to the lack of high energy particle events during cycle 24. Several eruptions poorly connected to Earth (eastern-hemisphere or behind-the-west-limb events) resulted in very large SEP events detected by the STEREO spacecraft. Some very fast CMEs, likely to have accelerated particles to GeV energies, did not result in a GLE event because of poor latitudinal connectivity. The stringent latitudinal requirement suggests that the highest energy particles are likely accelerated in the nose part of shocks. There were also well-connected fast CMEs, which did not seem to have accelerated high energy particles due to possible unfavorable ambient conditions (high Alfven speed, overall reduction in acceleration efficiency in cycle 24).

Extremely Microwave-Rich Solar Flare Observed with Nobeyama Radioheliograph

A compact flare was observed with Nobeyama Radioheliograph (NoRH) slightly behind the west limb on 2011 March 10. The microwave peak flux values at 17 and 34 GHz were about 210 and 133 sfu, respectively. From the correlation between the 17 GHz peak flux and the GOES 1-8 Å soft X-ray peak flux, M1.5-class is expected for this microwave flux. However, only the B1-level enhancement was detected in the GOES 1-8 Å soft X-ray light curve on the C1-level background during the flare period. In addition to microwaves, Suzaku detected hard X-ray emissions, even in the energy range above 100 keV. It is clear that high-energy electrons were effectively produced in this flare, while the thermal emission was very weak. Why did this flare have this unique feature? The following two cases are considered. One is the case that a magnetic trap for electrons works effectively, and that each electron continues to emit microwaves in its relatively long lifetime. The other is that the magnetic field around the looptop region is intense, and relatively a large number of lower-energy electrons emit microwaves. Considering the observational facts, such as the short duration and the small flare loop, the latter case is more plausible.

XMM-NewtonandSwiftobservations of XTE J1743-363

XTE J1743-363 is a poorly known hard X-ray transient, which displays short and intense flares similar to those observed from supergiant fast X-ray transients. The probable optical counterpart shows spectral properties similar to those of an M8 III giant, thus suggesting that XTE J1743-363 belongs to the class of the symbiotic X-ray binaries class. In this paper we report on the first dedicated monitoring campaign of the source in the soft X-ray range with XMM-Newton and Swift /XRT. These observations confirmed the association of XTE J1743-363 with the previously suggested M8 III giant and the classification of the source as a member of the symbiotic X-ray binaries. In the soft X-ray domain, XTE J1743-363 displays a high absorption (~6 × 1022 cm-2) and variability on time scales of hundreds to few thousand seconds, typical of wind-accreting systems. A relatively faint flare (peak X-ray flux 3 × 10-11 erg/cm2/s) lasting ~4 ks is recorded during the XMM-Newton observation and interpreted in terms of the wind accretion scenario.

Statistical relationship between CME speed and soft X-ray peak flux of the associated flare during solar cycle 23

AbstractThe relationship between the speed of coronal mass ejections and the peak soft X-ray flux of the associated flares is studied for events occurring near the solar limbs between 1996 and 2008. An improved, though still moderate, correlation between the two parameters is found.

Soft X-ray Fluxes of Major Flares Far Behind the Limb as Estimated Using STEREO EUV Images

With increasing solar activity since 2010, many flares from the backside of the Sun have been observed by the Extreme Ultraviolet Imager (EUVI) on either of the twin STEREO spacecraft. Our objective is to estimate their X-ray peak fluxes from EUVI data by finding a relation of the EUVI with GOES X-ray fluxes. Because of the presence of the Fe xxiv line at 192 A, the response of the EUVI 195 A channel has a secondary broad peak around 15 MK, and its fluxes closely trace X-ray fluxes during the rise phase of flares. If the flare plasma is isothermal, the EUVI flux should be directly proportional to the GOES flux. In reality, the multithermal nature of the flare and other factors complicate the estimation of the X-ray fluxes from EUVI observations. We discuss the uncer- tainties, by comparing GOES fluxes with the high cadence EUV data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). We conclude that the EUVI 195 A data can provide estimates of the X-ray peak fluxes of intense flares (e.g., above M4 in the GOES scale) with uncertainties of a factor of a few. Lastly we show examples of intense flares from regions far behind the limb, some of which show eruptive signatures in AIA images.

A Study of Connections Between Solar Flares and Subsurface Flow Fields of Active Regions

We investigate the connections between the occurrence of major solar flares and subsurface dynamic properties of active regions. For this analysis, we select five active regions that produced a total of 11 flares with peak X-ray flux intensity higher than M5.0. The subsurface velocity fields are obtained from time–distance helioseismology analysis using SDO/HMI (Solar Dynamics Observatory/Helioseismic and Magnetic Imager) Doppler observations, and the X-ray flux intensity is taken from GOES (Geostationary Operational Environmental Satellites). It is found that among the eight amplitude bumps in the evolutionary curves of subsurface kinetic helicity, five (62.5%) of them had a flare stronger than M5.0 occurring within 8 hours, either before or after the bumps. Another subsurface parameter is the Normalized Helicity Gradient Variance (NHGV), reflecting kinetic helicity spread in different depth layers; it also shows bumps near the occurrence of these solar flares. Although there is no one-to-one correspondence between the flare and the subsurface properties, these observational phenomena are worth further studies to better understand the flares’ subsurface roots, and to investigate whether the subsurface properties can be used for major flare forecasts.

Magnetic Flux Changes and Cancellation Associated with X-Class and M-Class Flares

We perform a statistical study of permanent changes in longitudinal fields associated with solar flares by tracking magnetic features. The YAFTA feature tracking algorithm is applied to GONG++ one-minute magnetograms for 77 X-class and M-class flares to analyze the evolution and interaction of the magnetic features and to estimate the amount of canceled magnetic flux. We find that significantly more magnetic flux decreases than increases occurred during the flares, consistent with a model of collapsing loop structure for flares. Correlations between both total (unsigned) and net (signed) flux changes and the GOES peak X-ray flux are dominated by X-class flares at limb locations. The flux changes were accompanied in most cases by significant cancellation, most of which occurred during the flares. We find that the field strength and complexity near the polarity inversion line are approximately equally important in the flux cancellation processes that accompany the flares. We do not find a correlation between the flux cancellation events and the stepwise changes in the magnetic flux in the region.

Cross Comparison of Solar X‐Ray Data Between FY‐2C/D Satellite and GOES Satellite

AbstractFengyun 2 (FY‐2) satellite is the first generation of geostationary meteorological satellite of China. The solar X‐ray detector aboard on FY‐2C/D has capability to observe the solar X‐ray flux of &gt;5.18 keV and &gt;3.27 keV, respectively. For the purpose of examining the effectiveness of FY‐2C/D X‐ray data, we compare them with the similar data of GOES, and find that these two categories of data are well consistent in temporal characters and X‐ray flux during solar flare events. By the cross comparison of the X‐ray peak flux for 85 solar flare events from November 2004 to June 2010, it is found that the linear correlative coefficient is 0.795 between FY‐2C and GOES data in 1~8 Å, and the corresponding coefficients between FY‐2D and GOES data in 0.5~3 Å and 1~8 Å are 0.921 and 0.989, respectively. The results indicate that the FY‐2C/D solar X‐ray data are quite reliable for monitoring, warning and researching of the solar X‐ray flare events.

AUTOMATED SOLAR FLARE STATISTICS IN SOFT X-RAYS OVER 37 YEARS OFGOESOBSERVATIONS: THE INVARIANCE OF SELF-ORGANIZED CRITICALITY DURING THREE SOLAR CYCLES

We analyzed the soft X-ray light curves from the {\sl Geostationary Operational Environmental Satellites (GOES)} over the last 37 years (1975-2011) and measured with an automated flare detection algorithm over 300,000 solar flare events (amounting to $\approx 5$ times higher sensitivity than the NOAA flare catalog). We find a powerlaw slope of $\alpha_F=1.98\pm0.11$ for the (background-subtracted) soft X-ray peak fluxes that is invariant through three solar cycles and agrees with the theoretical prediction $\alpha_F=2.0$ of the {\sl fractal-diffusive self-organized criticality (FD-SOC)} model. For the soft X-ray flare rise times we find a powerlaw slope of $\alpha_T =2.02\pm0.04$ during solar cycle minima years, which is also consistent with the prediction $\alpha_T=2.0$ of the FD-SOC model. During solar cycle maxima years, the powerlaw slope is steeper in the range of $\alpha_T \approx 2.0-5.0$, which can be modeled by a solar cycle-dependent flare pile-up bias effect. These results corroborate the FD-SOC model, which predicts a powerlaw slope of $\alpha_E=1.5$ for flare energies and thus rules out significant nanoflare heating. While the FD-SOC model predicts the probability distribution functions of spatio-temporal scaling laws of nonlinear energy dissipation processes, additional physical models are needed to derive the scaling laws between the geometric SOC parameters and the observed emissivity in different wavelength regimes, as we derive here for soft X-ray emission. The FD-SOC model yields also statistical probabilities for solar flare forecasting.

The Free Energy of NOAA Solar Active Region AR 11029

The NOAA active region (AR) 11029 was a small but highly active sunspot region which produced 73 GOES soft X-ray flares during its transit of the disk in late October 2009. The flares appear to show a departure from the well-known power law frequency-size distribution. Specifically, too few GOES C-class and no M-class flares were observed by comparison with a power law distribution (Wheatland, Astrophys. J. 710, 1324, 2010). This was conjectured to be due to the region having insufficient magnetic energy to power the missing large events. We construct nonlinear force-free extrapolations of the coronal magnetic field of AR 11029 using data taken on 24 October by the SOLIS Vector SpectroMagnetograph (SOLIS/VSM) and data taken on 27 October by the Hinode Solar Optical Telescope SpectroPolarimeter (Hinode/SP). Force-free modeling with photospheric magnetogram data encounters problems, because the magnetogram data are inconsistent with a force-free model. We employ a recently developed “self-consistency” procedure which addresses this problem and accommodates uncertainties in the boundary data (Wheatland and Régnier, Astrophys. J. 700, L88, 2009). We calculate the total energy and free energy of the self-consistent solution, which provides a model for the coronal magnetic field of the active region. The free energy of the region was found to be ≈ 4×1029 erg on 24 October and ≈ 7×1031 erg on 27 October. An order of magnitude scaling between RHESSI non-thermal energy and GOES peak X-ray flux is established from a sample of flares from the literature and is used to estimate flare energies from the observed GOES peak X-ray flux. Based on the scaling, we conclude that the estimated free energy of AR 11029 on 27 October when the flaring rate peaked was sufficient to power M-class or X-class flares; hence, the modeling does not appear to support the hypothesis that the absence of large flares is due to the region having limited energy.

Impact factor for the ionospheric total electron content response to solar flare irradiation

On the basis of ionospheric total electron content (TEC) enhancement over the subsolar region during flares, and combined with data of the peak X-ray flux in the 0.1-0.8 nm region, EUV increase in the 0.1-50 and 26-34 nm regions observed by the SOHO Solar EUV Monitor EUV detector, also with the flare location on the solar disc, the relationship among these parameters is analyzed statistically. Results show that the correlation between ionospheric TEC enhancement and the soft X-ray peak flux in the 0.1-0.8 nm region is poor, and the flare location on the solar disc is one noticeable factor for the impact strength of the ionospheric TEC during solar flares. Statistics indicate clearly that, at the same X-ray class, the flares near the solar disc center have much larger effects on the ionospheric TEC than those near the solar limb region. For the EUV band, although TEC enhancements and EUV flux increases in both the 0.1-50 and 26-34 nm regions have a positive relation, the flux increase in the 26-34 nm region during flares is more correlative with TEC enhancements. Considering the possible connection between the flare location on the solar disc and the solar atmospheric absorption to the EUV irradiation, an Earth zenith angle is introduced, and an empirical formula describing the relationship of TEC enhancement and traditional flare parameters, including flare X-ray peak and flare location information, is given. In addition, the X-ray class of the flare occurring on 4 November 2003, which led the saturation of the X-ray detector on GOES 12, is estimated using this empirical formula, and the estimated class is X44.

Finding a 24-day orbital period for the X-ray binary 1A 1118-616

We report the first determination of the binary period and orbital ephemeris of the Be X-ray binary containing the pulsar 1A 1118-616 (35 years after the discovery of the source). The orbital period is found to be Porb = 24.0 ± 0.4days. The source was observed by RXTE during its last large X-ray outburst in January 2009, which peaked at MJD 54845.4, by taking short observations every few days, covering an elapsed time comparable to the orbital period. Using the phase connection technique, pulse arrival time delays could be measured and an orbital solution determined. The data are consistent with a circular orbit and the time of 90 degrees longitude was found to be Tπ/2 = MJD 54845.37(10), which is coincident with that of the peak X-ray flux.

ABRUPT LONGITUDINAL MAGNETIC FIELD CHANGES IN FLARING ACTIVE REGIONS

We characterize the changes in the longitudinal photospheric magnetic field during 38 X-class and 39 M-class flares within $65^{\circ}$ of disk-center using 1-minute GONG magnetograms. In all 77 cases we identify at least one site in the flaring active region where clear, permanent, stepwise field changes occurred. The median duration of the field changes was about 15 minutes and was approximately equal for X-class and for M-class flares. The absolute values of the field changes ranged from the detection limit of $\sim\!\!10$~G to as high as $\sim\!\!450$~G in two exceptional cases. The median value was 69~G. Field changes were significantly stronger for X-class than for M-class flares and for limb flares than for disk-center flares. Longitudinal field changes less than 100~G tended to decrease longitudinal field strengths, both close to disk-center and close to the limb, while field changes greater than 100~G showed no such pattern. Likewise, longitudinal flux strengths tended to decrease during flares. Flux changes, particularly net flux changes near disk-center, correlated better than local field changes with GOES peak X-ray flux. The strongest longitudinal field and flux changes occurred in flares observed close to the limb. We estimate the change of Lorentz force associated with each flare and find that this is large enough in some cases to power seismic waves. We find that longitudinal field decreases would likely outnumber increases at all parts of the solar disk within $65^{\circ}$ of disk-center, as in our observations, if photospheric field tilts increase during flares as predicted by Hudson et al.

MAGNETIC NON-POTENTIALITY OF SOLAR ACTIVE REGIONS AND PEAK X-RAY FLUX OF THE ASSOCIATED FLARES

Predicting the severity of the solar eruptive phenomena like flares and Coronal Mass Ejections (CMEs) remains a great challenge despite concerted efforts for several decades. The advent of high quality vector magnetograms obtained from Hinode (SOT/SP) has increased the possibility of meeting this challenge. In particular, the Spatially Averaged Signed Shear Angle (SASSA) seems to be an unique parameter to quantify the non-potentiality of the active regions. We demonstrate the usefulness of SASSA for predicting the flare severity. For this purpose we present case studies of the evolution of magnetic non-potentiality using 115 vector magnetograms of four active regions namely ARs NOAA 10930, 10960, 10961 and 10963 during December 08-15, 2006, June 03-10, 2007, June 28-July 5, 2007 and July 10-17, 2007 respectively. The NOAA ARs 10930 and 10960 were very active and produced X and M class flares respectively, along with many smaller X-ray flares. On the other hand, the NOAA ARs 10961 and 10963 were relatively less active and produced only very small (mostly A and B-class) flares. For this study we have used a large number of high resolution vector magnetograms obtained from Hinode (SOT/SP). The analysis shows that the peak X-ray flux of the most intense solar flare emanating from the active regions depends on the magnitude of the SASSA at the time of the flare. This finding of the existence of a lower limit of SASSA for a given class of X-ray flare will be very useful for space weather forecasting. We have also studied another non-potentiality parameter called mean weighted shear angle (MWSA) of the vector magnetograms along with SASSA. We find that the MWSA does not show such distinction as the SASSA for upper limits of GOES X-Ray flux of solar flares, however both the quantities show similar trends during the evolution of all active regions studied.

The late jet in gamma-ray bursts and its interactions with a supernova ejecta and a cocoon

Late X-ray flares observed in X-ray afterglows of gamma-ray bursts (GRBs) suggest late central engine activities at a few minuets to hours after the burst. A few unambiguously confirmed cases of supernova associations with nearby long GRBs imply that an accompanying supernova-like component might be a common feature in all long GRB events. These motivate us to study the interactions of a late jet, responsible for a x-ray flare, with various components in a stellar explosion, responsible for a GRB. These components include a supernova shell-like ejecta, and a cocoon that was produced when the main jet producing the GRB itself was propagating through the progenitor star. We find that the interaction between the late jet and the supernova ejecta may produce a luminous (up to 10^49 erg s^-1) thermal X-ray transient lasting for ~ 10 s. The interaction between the late jet and the cocoon produces synchrotron self-absorbed non-thermal emission, with the observed peak X-ray flux density from 0.001 micro Jy to 1 mJy at 1 keV and a peak optical flux density from 0.01 micro Jy to 0.1 Jy (for a redshift z= 2). The light curve due to the late jet - cocoon interaction has very small pulse-width-to-time ratio, \Delta t / t \approx 0.01 - 0.5, where t is the pulse peak time since the burst trigger. Identifying these features in current and future observations would open a new frontier in the study of GRB progenitor stars.