TITLE: GCN CIRCULAR
NUMBER: 39563
SUBJECT: INTEGRAL: end of scientific operations
DATE: 25/03/03 08:52:32 GMT
FROM: Carlo Ferrigno <carlo.ferrigno(a)unige.ch>
From 2025-03-04 at 12:08:04 UT, data from the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) will not be transmitted anymore to the INTEGRAL science data centre (ISDC) owing to the end of scientific operations, more than 22 years after its launch. As a consequence, the INTEGRAL Burst Alert System (IBAS) will …
[View More]be discontinued and no more alerts nor GCN notices distributed (see https://gcn.gsfc.nasa.gov/integral.html for the current INTEGRAL GCN notices).
The IBAS team thanks all the scientific community for the continuous support.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39563.
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TITLE: GCN CIRCULAR
NUMBER: 39562
SUBJECT: EP250302A: VLT near-infrared observations
DATE: 25/03/03 08:26:32 GMT
FROM: Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra(a)roma2.infn.it>
Rosa Becerra (U Rome), Yu-Han Yang (U Rome), Muskan Yadav (U Rome), Eleonora Troja (U Rome) report on behalf of the ERC BHianca team:
We observed the field of EP250302A (Dai et al., GCN 39556) with the HAWKI imager on the ESO VLT UT4 (Yepun). Observations began at T+14.1 h days and were carried …
[View More]out at an average airmass of about 1.9 in the J, H, and K filter.
We detect the optical counterpart (Zhu et al., GCN 39550; Busmann et al., GCN 39551; Leonini et al., GCN 39553; Wu et al., GCN 39555, Xin et al., GCN 39558) in all three filters
at a magnitude J~20 mag (Vega) calibrated using nearby stars in the 2MASS Catalogue.
We thank the staff at the VLT for the rapid execution of these observations.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39562.
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TITLE: GCN CIRCULAR
NUMBER: 39561
SUBJECT: EP250302A: VLT/X-shooter tentative redshift
DATE: 25/03/03 08:21:14 GMT
FROM: Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra(a)roma2.infn.it>
Yu-Han Yang (U Rome), Eleonora Troja (U Rome), and Rosa Becerra (U Rome) report on behalf of the ERC BHianca team:
We observed the field of EP250302A (Dai et al., GCN 39556) with the X-Shooter spectrograph on the ESO VLT UT3 (Melipal). Observations began at T+13.6 hours and obtained a total …
[View More]of 4x600s spectra at an average airmass of about 1.9.
At the position of the optical counterpart (Zhu et al., GCN 39550; Busmann et al., GCN 39551; Leonini et al., GCN 39553; Wu et al., GCN 39555, Xin et al., GCN 39558) we detect a strong continuum in all three arms. Based on a preliminary analysis, we identify weak absorption lines consistent with Fe II and the Mg II doublet at redshift z=0.549.
Our observations suggest that the EP transient is not related to the nearby galaxy noted by Busmann et al., GCN 39551, but lies at higher redshift.
We thank the staff at the VLT, for the rapid execution of these observations.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39561.
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TITLE: GCN CIRCULAR
NUMBER: 39561
SUBJECT: EP250302A: VLT/X-shooter tentative redshift
DATE: 25/03/03 08:21:14 GMT
FROM: Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra(a)roma2.infn.it>
Yu-Han Yang (U Rome), Eleonora Troja (U Rome), and Rosa Becerra (U Rome) report on behalf of the ERC BHianca team:
We observed the field of EP250302A (Dai et al., GCN 39556) with the X-Shooter spectrograph on the ESO VLT UT3 (Melipal). Observations began at T+13.6 hours and obtained a total …
[View More]of 4x600s spectra at an average airmass of about 1.9.
At the position of the optical counterpart (Zhu et al., GCN 39550; Busmann et al., GCN 39551; Leonini et al., GCN 39553; Wu et al., GCN 39555, Xin et al., GCN 39558) we detect a strong continuum in all three arms. Based on a preliminary analysis, we identify weak absorption lines consistent with Fe II and the Mg II doublet at redshift z=0.549.
Our observations suggest that the EP transient is not related to the nearby galaxy noted by Busmann et al., GCN 39551, but lies at higher redshift.
We thank the staff at the VLT, for the rapid execution of these observations.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39561.
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TITLE: GCN CIRCULAR
NUMBER: 39560
SUBJECT: EP250302a: OHP/T193 optical and spectroscopic observations
DATE: 25/03/03 08:13:10 GMT
FROM: Benjamin Schneider at MIT <bschn(a)mit.edu>
C. Adami (LAM/Pytheas/AMU), B. Schneider (LAM), S. Basa (LAM/OHP/Pytheas/AMU), M. Dennefeld (IAP/CNRS/Sorbonne U.), E. Le Floc'h (CEA/Irfu), J. P. Palmerio (CEA/Irfu), A. Saccardi (CEA/Irfu), J. Schmitt (OHP/Pytheas/AMU), F. Schüssler (CEA/DPhP), D. Turpin (CEA/Irfu), S. D. Vergani (CNRS, Paris Obs./…
[View More]LUX) report on behalf of the larger collaboration:
We observed the field of the EP250302a (Dai et al. GCN 39556) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. We obtained 2 exposures (2x600 s) in the r-band. The first epoch started at 23:38:10 UT on 2025-03-02 (8.03h after the trigger) and the second one at 01:02:41 UT on 2025-03-03 (9.43h after the trigger). In both images, we clearly detected the optical counterpart reported by Zhu et al., GCN 39550, Busmann et al., GCN 39551, Leonini et al., GCN 39553 and Xin et al., GCN 39558.
The preliminary magnitudes derived for that source are:
r = 20.75 +/- 0.06 mag (AB)
r = 20.85 +/- 0.07 mag (AB)
The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitudes are not corrected for Galactic extinction.
In addition, we obtained 2x30 min exposures with the MISTRAL spectroscopic blue setting, covering from 4200 to 8000 AA starting at 00:20:45UT (midtime = T0+8h45).
In a preliminary reduction of the spectrum, we detect a very faint continuum at the GRB position, covering the whole spectral range and suggesting a redshift lower than 2.5.
We acknowledge the excellent support from the Observatoire de Haute-Provence and in particular Neda Heidari and Stephane Favard for the MISTRAL observations.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39560.
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TITLE: GCN CIRCULAR
NUMBER: 39559
SUBJECT: EP250302a: Global MASTER-Net observations report
DATE: 25/03/03 08:09:37 GMT
FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru>
V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko,
A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin,
V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile, F. Podesta, R.…
[View More]Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP250302a ( EP Team et al., GCN 39556) errorbox 328 sec after notice time and 57360 sec after trigger time at 2025-03-03 07:32:04 UT, with upper limit up to 19.8 mag. The observations began at zenith distance = 73 deg. The sun altitude is -35.3 deg.
The galactic latitude b = 70 deg., longitude l = 190 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2797947
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
57390 | 2025-03-03 07:32:04 | MASTER-OAFA | (11h 18m 00.44s , +33d 56m 34.8s) | C | 60 | 19.8 |
58371 | 2025-03-03 07:48:24 | MASTER-OAFA | (11h 18m 02.25s , +33d 57m 27.8s) | C | 60 | 19.5 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39559.
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TITLE: GCN CIRCULAR
NUMBER: 39558
SUBJECT: EP250302a: Xinglong F60B optical observation
DATE: 25/03/03 07:52:34 GMT
FROM: Liping Xin at NAOC, SVOM <xlp(a)nao.cas.cn>
L. P. Xin, X. H. Han, P. P. Zhang, J. Wang, C. Wu, Y. L. Qiu, H. B. Cai, H. L. Li, X. M. Lu, R. S. Zhang, Y. J. Xiao, J. S. Deng, Z. H. Yao, Y. N. Ma, J. Y. Wei (NAOC), X. G. Wang, E. W. Liang (GXU) report:
We observed location of EP250302a (Trigger ID: 01709132186, Dai et al., GCN 39556) with F60B telescope in R …
[View More]band at Xinglong observatory, China. Observations started at 15:42:43 UT on 2025-03-02, 6.5 min after the EP-WXT trigger.
The optical counterpart reported (Zhu et al., GCN 39550, Busmann et al., GCN 39553, Leonini et al., GCN 39553, Wu et al., GCN 39555) within the FXT and XRT locations (Dai et al., GCN 39556, Page et al., GCN 39557) was clearly detected in the stacked image with an exposure time of 10*50 sec. The brightness was estimated to be R=18.36+/-0.13 mag calibrated to USNO B1.0 R2 magnitude.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39558.
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TITLE: GCN CIRCULAR
NUMBER: 39557
SUBJECT: EP250302a: Swift-XRT observations of a fading X-ray source
DATE: 25/03/03 07:43:50 GMT
FROM: K.L. Page at U Leicester <klp5(a)leicester.ac.uk>
K.L. Page, P.A. Evans (U.Leicester) and J. DeLaunay (PSU) report on
behalf of the Swift XRT Team:
On 2025 March 02 at 16:36 UT, Swift started observing EP250302a, 3.6 ks
after the trigger (GCN Circ. 39556). A fading X-ray source was identified,
at a position of RA, Dec = 169.51508, +33.5858, …
[View More]which is equivalent to
RA (J2000): 11h 18m 03.62s
Dec (J2000): +33d 35′ 09.0″
with an uncertainty of 2.6 arcsec (radius, 90% confidence). This position
is consistent with the optical counterpart reported in GCNs 39550, 39551,
39553 and 39555.
The X-ray flux at the start of the observation was (5.0 +-/ 1.1) x 10^-11
erg cm^-2 s^-1 (0.3 - 10 keV), fading to a value of (7.1 +/- 0.9) x 10^-12
erg cm^-2 s^-1 at 8 ks post trigger. The decay can be fitted with a
power-law slope of alpha = 2.36 (+0.37/-0.32).
View this GCN Circular online at https://gcn.nasa.gov/circulars/39557.
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TITLE: GCN CIRCULAR
NUMBER: 39556
SUBJECT: EP250302a: Einstein Probe detection of an X-ray transient
DATE: 25/03/03 07:23:40 GMT
FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn>
C. Y. Dai (NJU), Y.Q. Zhao (USTC, PRIC), X. Mao, S. X. Wen, W. Yuan (NAO, CAS) report on behalf of the Einstein Probe team:
We report on the detection of an X-ray transient by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP250302a. The transient triggered …
[View More]EP-WXT (ID: 01709132186) at 2025-03-02T15:36:04 (UTC). The light curve shows a burst lasting at least 30s, with a peak of about 9 x 10^(-9) erg/s/cm^2. The spectrum can be fitted by an absorbed power-law with a photon index of 0.6(-0.4/+0.4) (with the column density fixed at the Galactic one of 2.36 x 10^20 cm^-2). The derived average unabsorbed 0.5-4 keV flux is 7.0(-1.6, +2.0) x 10^(-9) erg/s/cm^2. The uncertainties are at the 90% confidence level for the above parameters.
A follow-up observation with the Follow-up X-ray Telescope (FXT) was performed automatically. Within the WXT error cirlce, an uncatalogued X-ray source was detected at R.A. = 169.5151 deg, DEC = 33.5851 deg (J2000) with an uncertainty of 10 arcsec in radius (90% C.L. statistical and systematic). A secondary burst is detected starting at 2025-03-02T15:56:06 (UTC) and last for ~500 s, the spectrum during the flare can be fitted by an absorbed power-law with a photon index of 1.8(-0.05/+0.0.5) (with the column density fixed at the Galactic one of 2.36 x 10^20 cm^-2), and the derived average unabsorbed 0.5-10 keV flux is 9.6(-0.4, +0.4) x 10^(-11) erg/s/cm^2.
Additionally, we note that the optical counterparts (GCN 39550, GCN 39551, GCN 39553, and GCN 39555) lie within the positional uncertainty of EP-FXT.
Further follow-up observations are encouraged to identify the nature of this X-ray transient.
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).
View this GCN Circular online at https://gcn.nasa.gov/circulars/39556.
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TITLE: GCN CIRCULAR
NUMBER: 39555
SUBJECT: EP250302a: SVOM/C-GFT optical observations
DATE: 25/03/03 05:21:19 GMT
FROM: SVOM_group <svomgroup(a)bao.ac.cn>
Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC), Yulei, Qiu(NAOC), Jing Wang(NAOC), Jianyan Wei (NAOC) report on behalf of the SVOM/C-GFT team:
We observed the field of EP250302a detected by …
[View More]Einstein Probe (Trigger ID: 01709132186) with C-GFT. Our observations were started on 2025-03-02T15:43:07 UTC, ~7.05 mins after the trigger. The optical counterpart (reported by Zhu et al. GCN 39550, Busmann et al., GCN 9551,Leonini et al., GCN 39553) was clearly detected in stacked images of band g,r and i. The results are,
(T-T0)_mid(sec) mag mag_err band
------------------------------------------
462 18.13 +/- 0.10 i
553 18.31 +/- 0.09 g
664 18.14 +/- 0.07 r
The photometry was calibrated with nearby Pan-STARRS1 stars. Further analysis is on-going.
We thank the observation assistants Bowen Li at Jilin observatory for their excellent support.
Chinese Ground Follow-up Telescope of SVOM mission is located at Jilin, Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg x 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39555.
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