TITLE: GCN CIRCULAR
NUMBER: 36710
SUBJECT: EP240618a: TRT optical upper limit
DATE: 24/06/20 02:58:48 GMT
FROM: S. Tinyanont at National Astronomical Research Institute of Thailand <samaporn(a)narit.or.th>
S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), S.Q. Jiang, J. An, X. Liu, S.Y. Fu, Z.P. Zhu, Z. Fan, W.X. Li, N.C. Sun, Y.N. Wang, D. Xu (NAOC) report on behalf of a large collaboration:
We observed the field of EP240618a (Sun et al., GCN 36690) using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Sierra Remote Observatory, California, USA. Observations started at 07:37:06.059 UTC on 2024-06-18, i.e., 1.89 hr after the EP trigger, and 15 x 120 s R-band frames were obtained.
No uncatalogued optical transient is detected in the stacked R-band image within the 30-arcsec EP/FXT error circle (Sun et al., GCN 36690), down to a 5-sigma limiting magnitude of R ~ 20.3, calibrated with Pan-STARRS sources in the field. Also there is no apparent brightening for any catalogued source within the EP/FXT error circle.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36710.
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TITLE: GCN CIRCULAR
NUMBER: 36708
SUBJECT: Fermi GRB 240619A: Global MASTER-Net observations report
DATE: 24/06/19 23:45:42 GMT
FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)
MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 240619A ( Fermi GBM team, GCN 36694) errorbox 55438 sec after notice time and 55481 sec after trigger time at 2024-06-19 19:08:12 UT, with upper limit up to 16.7 mag. The observations began at zenith distance = 68 deg. The sun altitude is -17.7 deg.
The galactic latitude b = 60 deg., longitude l = 227 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2499301
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
55512 | 2024-06-19 19:08:12 | MASTER-Kislovodsk | (10h 49m 58.96s , +16d 22m 16.8s) | C | 60 | 16.7 |
57629 | 2024-06-19 19:43:30 | MASTER-Kislovodsk | (10h 43m 55.90s , +14d 27m 58.5s) | C | 60 | 16.3 |
57710 | 2024-06-19 19:44:50 | MASTER-Kislovodsk | (10h 44m 03.04s , +14d 26m 52.8s) | C | 60 | 16.1 |
58111 | 2024-06-19 19:51:32 | MASTER-Kislovodsk | (10h 49m 57.47s , +16d 21m 38.9s) | C | 60 | 15.9 |
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/36708.
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TITLE: GCN CIRCULAR
NUMBER: 36707
SUBJECT: EP240617a: STEP/T80S optical limits
DATE: 24/06/19 23:42:54 GMT
FROM: André Santos at Centro Brasileiro de Pesquisas Físicas (CBPF) <andsouzasanttos(a)gmail.com>
A. Santos (CBPF), C. R. Bom (CBPF), C. D. Kilpatrick (Northwestern), L. Santana-Silva (CBPF), P. Darc (CBPF), C. Mendes de Oliveira (IAG-USP) report on behalf of the STEP collaboration:
We conducted optical follow up of the fast X-ray transient EP240617a by the Einstein Probe (GCN [36691](https://gcn.nasa.gov/circulars/36691), [36692](https://gcn.nasa.gov/circulars/36691)) with the T80S 0.8-m robotic telescope using the 1.4 x 1.4 field-of-view T80S-Cam imager (see Santos et al., 2024, MNRAS, 529, 59 for details). The observations started on June 19, 05:10 UT (~41 hours after the trigger). We obtained 360s (3x120s) images in both i and z bands with the T80S camera centered at R.A.=19:00:07.29 and Decl.=-22:33:39.60 (J2000). Subtracting Pan-STARRS 3pi template images from the T80S frames using photpipe (Rest et al., 2005), we do not detect any sources in our difference images and derive 3-sigma limiting magnitudes of z > 20.6 and i > 20.9 mag for any optical transient.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36707.
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TITLE: GCN CIRCULAR
NUMBER: 36706
SUBJECT: GRB 240615A: possible transient detection from Wendelstein observations
DATE: 24/06/19 22:11:12 GMT
FROM: Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann(a)physik.lmu.de>
Malte Busmann (LMU), Daniel Gruen (LMU), Brendan O’Connor (Carnegie Mellon U.), Antonella Palmese (Carnegie Mellon U.), Christoph Ries (LMU), Arno Riffeser (LMU/MPE) report:
With the 3KK optical-NIR imager at the 2m Fraunhofer telescope at Wendelstein Observatory, Germany, we have followed up the GRB 240615A reported by GCN 36671, 36672. Our observations began at ~3.2 days after the GRB.
We detect one source at 10sigma significance that is consistent with the location (90% error of ~9") of the Swift-XRT uncatalogued X-ray source reported in GCN 36683. We report the following photometric measurements and 3-sigma upper limits for this source (hereafter referred to as Source 1):
Name RA(J2000) dec(J2000) UTC mag_r mag_i mag_J
Source 1 21:44:23.63 +38:34:08.89 2024-06-18T22:44:19 >24.0 24.0 +/- 0.5 20.36 +/- 0.09
We also obtained a tentative detection of Source 1 in images taken about 22 h before this detection (~2.3 days after the GRB). There is evidence at the 3sigma level that Source 1 was brightening between the two epochs. We note that Source 1 is extremely red in color with i-J>3 mag.
A second source (Source 2) is marginally detected at RA, dec (J2000) = 21:44:23.8, +38:34:03.4 in both r and i-bands. We note the marginal detection of an underlying source in PS1 imaging at both of these locations (Source 1 and Source 2).
Further observations are scheduled and additional follow-up is encouraged.
Magnitudes are in the AB system and not corrected for the significant Milky Way extinction along this line of sight.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36706.
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TITLE: GCN CIRCULAR
NUMBER: 36704
SUBJECT: LIGO/Virgo/KAGRA S240615dg: Updated Sky localization
DATE: 24/06/19 21:51:02 GMT
FROM: Nihar.Gupte(a)aei.mpg.de
The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:
We have conducted further analysis of the LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S240615dg (GCN Circular 36669). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline0.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S240615dg
For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is well fit by an ellipse with an area of 5 deg2 described by the following DS9 region (right ascension, declination, semi-major axis, semi-minor axis, position angle of the semi-minor axis):
icrs; ellipse(00h31m, +45d40m, 1.36d, 1.20d, 111.41d)
Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1420 +/- 236 Mpc (a posteriori mean +/- standard deviation).
For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/.
[1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. (2023) arXiv:2307.13380
View this GCN Circular online at https://gcn.nasa.gov/circulars/36704.
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TITLE: GCN CIRCULAR
NUMBER: 36703
SUBJECT: LIGO/Virgo/KAGRA S240618ah: Updated Sky localization
DATE: 24/06/19 21:37:35 GMT
FROM: Michael J. Williams at University of Portsmouth <michael.williams(a)ligo.org>
The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:
We have conducted further offline analysis of the LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) data around the time of the compact binary merger (CBC) candidate S240618ah (GCN Circular 36689). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline0.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S240618ah
For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 5116 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 5939 +/- 2437 Mpc (a posteriori mean +/- standard deviation).
For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/.
[1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. (2023) arXiv:2307.13380
View this GCN Circular online at https://gcn.nasa.gov/circulars/36703.
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TITLE: GCN CIRCULAR
NUMBER: 36702
SUBJECT: EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
DATE: 24/06/19 19:11:32 GMT
FROM: Christophe Adami at LAM <christophe.adami(a)lam.fr>
C. Adami (LAM/Pytheas/AMU), E. Le Floc’h (CEA Paris-Saclay), F. Fortin (IRAP, Toulouse),
B. Schneider (MIT), J. Palmerio, A. Saccardi, S. Vergani (GEPI/Obs. de Paris), M. Dennefeld (IAP),
J. Schmitt, E. Schmitt, E. Molina (OHP/Pytheas), F. Schussler (DPhP CEA),
report on behalf of a larger collaboration:
We observed the field of EP240618a (GCN 36690; Sun et al., GCN 36701; Wu et al.) using the T193cm
telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. We
obtained 5400s (9x600s with dithering) in the Y-band between 21h13 and 22h47 UT on the 2024-06-18
(~16h after trigger) and 3900s (13x300s with dithering) in the i'-band between 22h53 on the 2024-06-
18 and 00h18 UT on the 2024-06-19 (~18h after trigger).
We do not detect any significant new objects in our MISTRAL images within the X-ray position
uncertainty area, nor in i band (3-sigma detection limit of 20.9) or Y band (3-sigma detection limit
of 19.85). We however have a hint of a detection close to the ~2-sigma detection limit in the
MISTRAL Y-band image at an approximate magnitude of Y~20.3 (with a large error bar) and located at
18:46:36.3, +23:49:55.2. This putative source is not visible at all in the MISTRAL i-band image.
We encourage further deeper follow-ups of this possible source to assess its existence.
The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the
magnitudes are not corrected for Galactic extinction.
We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean
Pierre Troncin for the MISTRAL observations.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36702.
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TITLE: GCN CIRCULAR
NUMBER: 36701
SUBJECT: EP240618a: BOOTES-6/DPRT optical upper limit
DATE: 24/06/19 15:31:34 GMT
FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct(a)iaa.es>
S.-Y. Wu, I. Perez-Garcia, E. Fernandez-Garcia, M. D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy and A. J. Castro-Tirado (IAA-CSIC, Granada), P. J. Meintjes and H. J. van Heerden (UFS, South Africa), A. Martin-Carrillo and L. Hanlon (UCD, Ireland), M. Gritsevich (Univ. of Helsinki), D. R. Xiong (Yunnan Observatories of CAS) and C. J. Perez del Pulgar (UMA, Malaga), on behalf of a larger collaboration, report:
Following the detection of the fast X-ray transient EP240618a by the Einstein Probe (Sun et al. GCNC 36690), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) observed the fast X-ray transient location starting on June 18, 20:52 UT (~ 15.1 h after trigger) in different optical bands. No new optical source is detected on the co-added images (clear-filter) within the EP/FXT 30” radius error box down to 20.2 mag.
We thank the staff at Boyden Observatory for their excellent support.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36701.
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