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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21842 results found.

  1. EP250702a: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  2. GRB 250704A: GRANDMA observations
  3. GRB 250704A: SVOM/ECLAIRs refined analysis
  4. GRB 250702B,D,E/EP250702A: JCMT sub-mm observations at 350 GHz
  5. GRB 250704B / EP250704a: 1.3 GHz MeerKAT Detection
  6. GRB 250702B,D,E / EP250702a: ALMA detection
  7. LIGO/Virgo/KAGRA S250629bs: Upper limits from Swift/BAT-GUANO
  8. LIGO/Virgo/KAGRA S250629ae: Upper limits from Swift/BAT-GUANO
  9. IceCube-250708A: No Candidates from WINTER
  10. IceCube-250708A: No Candidate Transients from the Zwicky Transient Facility
  11. GRB 250702B,D,E/EP250702A: MeerKAT radio observations at 1.28GHz
  12. GRB 250702B,D,E / EP250702a: 10 GHz detection with the VLA
  13. EP/WXT 01709181970: GOTO observations confirm stellar variability
  14. EP250704a/GRB 250704B: 10 GHz VLA detection
  15. GRB250702 B,D,E / EP250702a: MOSFIRE imaging of the afterglow
  16. LIGO/Virgo/KAGRA S250704ab: NED Galaxies in the 4-Update Localization Volume
  17. IceCube-250706A: No Candidates from WINTER
  18. IceCube-250706A: No Candidates from the Zwicky Transient Facility
  19. GRB 250704B / EP250704a: VLA radio detection
  20. Fermi GRB 250708A: Global MASTER-Net observations report
  21. IceCube-250708A: Global MASTER-Net observations report
  22. EP250704a/GRB250704B : HCT optical and NIR upper limits
  23. GRB 250706B: SVOM observations interpreted as the afterglow of GRB 250706C
  24. GRB 250704B: CALET Gamma-Ray Burst Monitor detection
  25. GRB 250704B / EP250704a: Mondy and AbAO optical observations
  26. GRB 250702F: radio detection with the VLA
  27. IceCube-250706A: EP-FXT follow-up observations
  28. Fermi-LAT Gamma-ray Observations of IceCube-250706A
  29. IceCube-250706A: Global MASTER-Net observations report
  30. GRB 250704A: SVOM/COLIBRÍ (FM-GFT) optical observations
  31. EP250702a/GRB250702 B,D,E: GRANDMA Upper Limit
  32. GRB 250706B: Swift/UVOT Detection
  33. EP250702a/ GRB 250702B: NuSTAR X-ray Observations
  34. GRB 250704A: Swift/BAT-GUANO localization skymap of a burst
  35. GRB 250702F: GRANDMA observations
  36. GRB 250706B: refined SVOM/MXT data analysis
  37. GRB 250706A: Swift/UVOT Upper Limits
  38. GRB 250706B: REM optical observations
  39. GRB 250706A: REM optical/NIR observations
  40. IceCube-250416A: DDOTI Optical Upper Limit
  41. IceCube-250706A: COLIBRÍ optical upper limits
  42. Swift GRB 250706A: Global MASTER-Net observations report
  43. GRB 250706A: JinShan optical upper limits
  44. GRB 250706A: SAO RAS optical observations
  45. EP250704A: NOWT Detection
  46. GRB 250706A: SVOM/C-GFT upper limit in eary phase
  47. GRB250706B: Swift-XRT counterpart detection
  48. GRB 250706B: iTelescope optical observations
  49. EP250704a / GRB 250704B: end of optical plateau phase and rapid fading of the counterpart
  50. GRB 250706B: TRT bright optical counterpart detection
  51. GRBs 250702B,C,D,E / EP250702a: J band upper limit by SYSU 80cm infrared telescope
  52. EP250702a/GRB250702 B,E,D: MeerKAT radio counterpart
  53. EP250702a/GRB 250702B,C,D,E: Archival radio observations from ASKAP VAST
  54. GRB 250704B: Swift/UVOT Upper Limits
  55. GRB 250704A: Swift/UVOT Detection
  56. EP250704a/GRB 250704B: GSP observations of the optical counterpart
  57. EP250704a/GRB 250704B: FTW optical and NIR observations of the counterpart
  58. GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  59. EP250704a / GRB 250704B: NOT observations of the optical afterglow
  60. EP250704a/GRB 250704B VLT/HAWK-I NIR afterglow detection
  61. GRB 250702F: Kilonova-Catcher optical afterglow detection
  62. GRB 250702F: Monte Agliale Observatory optical observations
  63. GRB250702F: afterglow detected by joint EP-ZTF shadowing program
  64. EP250704a / GRB 250704B: JinShan optical observations
  65. EP250704a / GRB 250704B: SAO RAS optical observations
  66. EP250704a / GRB 250704B : GROWTH-India Telescope optical observations
  67. GRBs 250702B,D,E / EP250702a: fast fading, extremely red counterpart
  68. LIGO/Virgo/KAGRA S250704ab: NED Galaxies in the 3-Initial Localization Volume
  69. EP250704a / GRB 250704B: Pan-STARRS iz-band imaging and photometry
  70. EP250704a: refined analysis of the EP-WXT and FXT follow-up observations
  71. LIGO/Virgo/KAGRA S250704ab: Upper limits from Fermi-GBM Observations
  72. GRBs 250702B/C/D/E / EP250702a: Swift/UVOT Upper Limits
  73. EP250704a / GRB250704B: Swift-XRT counterpart detection
  74. GRB 250702B / EP2050702a: FTW optical and NIR observations
  75. EP250704a / GRB 250704B - REM observations
  76. GRB 250702F: GROWTH-India Telescope optical observations
  77. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  78. EP250702a: WFST optical observations
  79. EP250704a: COLIBRÍ optical counterpart candidate
  80. GRB 250702F: optical photometry from Konkoly
  81. GRB 250704A: REM detection of the optical afterglow
  82. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  83. GRB 250702F: Swift/UVOT Detection
  84. Fermi GBM Analysis of GRB 250702B (formerly B,D,E); dissociation of C burst
  85. Fermi GRB 250703A: Global MASTER-Net observations report
  86. GRB 250702F: Leavitt Observatory optical observations
  87. GRBs 250702B,C,D,E / EP250702a: VLT/HAWK-I NIR candidate
  88. GRB 250702F: Skynet Optical Observations
  89. GRBs 250702B/C/D/E / EP250702a: Swift XRT localization
  90. EP250702a/GRB 250702B, C, D, E: EP-FXT follow-up observation
  91. GRB 250702F: TRT Optical Observation
  92. GRB 250703A: DDOTI Optical Upper Limit
  93. GRB 250702F: REM optical afterglow detection
  94. EP250702a: Global MASTER-Net observations report
  95. GRB 250702F: DDOTI Optical Observation
  96. GRB 250702B,C,D,E / EP 250702a: MAXI/GSC detection
  97. EP250702a/GRB 250702B,C,D,E: GOTO optical upper limits
  98. GRB 250702F: COLIBRÍ Observations of the Afterglow
  99. EP250702a : an X-ray transient detected by Einstein Probe likely associated with GRB 250702B,C,D,E
  100. Fermi GRB 250702E: Global MASTER-Net observations report

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