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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"

32552 results found.

  1. IceCube-250706A: Upper limits from a search for additional neutrino events in IceCube
  2. LIGO/Virgo/KAGRA S250705cb: Updated Sky localization
  3. LIGO/Virgo/KAGRA S250704ab: Updated Sky localization and EM Bright Classification
  4. LIGO/Virgo/KAGRA S250702n: Updated Sky localization
  5. LIGO/Virgo/KAGRA S250701bq: Updated Sky localization
  6. EP250704a/GRB250704B : HCT optical and NIR upper limits
  7. LIGO/Virgo/KAGRA S250701bp: Updated Sky localization
  8. GRB 250706B/C: Konus-Wind analysis of the prompt emission
  9. GRB 250706B: SVOM observations interpreted as the afterglow of GRB 250706C
  10. GRB 250704B: CALET Gamma-Ray Burst Monitor detection
  11. GRB 250704B / EP250704a: Mondy and AbAO optical observations
  12. GRB 250702F: radio detection with the VLA
  13. GRB 250706B/C: VLT/X-shooter redshift z = 0.942
  14. IceCube-250706A: EP-FXT follow-up observations
  15. Fermi-LAT Gamma-ray Observations of IceCube-250706A
  16. GRB 250706B/C: Fermi-LAT detection
  17. GRB 250704A: SVOM/COLIBRÍ (FM-GFT) optical observations
  18. EP250702a/GRB250702 B,D,E: GRANDMA Upper Limit
  19. GRB 250706B: Swift/UVOT Detection
  20. EP250702a/ GRB 250702B: NuSTAR X-ray Observations
  21. GRB 250706C: Konus-Wind detection of a very bright GRB ~1200 s before GRB 250706B
  22. GRB 250704A: Swift/BAT-GUANO localization skymap of a burst
  23. GRB 250702F: GRANDMA observations
  24. GRB 250706B: refined SVOM/MXT data analysis
  25. GRB 250706A: Swift/UVOT Upper Limits
  26. GRB 250706B: REM optical observations
  27. GRB 250706A: REM optical/NIR observations
  28. EP250706a/GRB 250706A: EP-WXT detection of a fast X-ray transient
  29. IceCube-250416A: DDOTI Optical Upper Limit
  30. IceCube-250706A: COLIBRÍ optical upper limits
  31. Swift GRB 250706A: Global MASTER-Net observations report
  32. GRB 250706A: JinShan optical upper limits
  33. GRB 250706A: SAO RAS optical observations
  34. EP250704A: NOWT Detection
  35. GRB 250706A: SVOM/C-GFT upper limit in eary phase
  36. GRB250706B: Swift-XRT counterpart detection
  37. GRB 250706B: iTelescope optical observations
  38. EP250704a / GRB 250704B: end of optical plateau phase and rapid fading of the counterpart
  39. GRB 250706B: SVOM/VT optical observation
  40. GRB 250706B: TRT bright optical counterpart detection
  41. GRB 250706A: GROWTH-India Telescope optical upper limit
  42. GRBs 250702B,C,D,E / EP250702a: J band upper limit by SYSU 80cm infrared telescope
  43. EP250702a/GRB250702 B,E,D: MeerKAT radio counterpart
  44. GRB 250703A: EIRSAT-1 GMOD Detection
  45. EP250702a/GRB 250702B,C,D,E: Archival radio observations from ASKAP VAST
  46. GRB 250704B: Swift/UVOT Upper Limits
  47. GRB 250704A: Swift/UVOT Detection
  48. LIGO/Virgo/KAGRA S250705cb: Identification of a GW compact binary merger candidate
  49. Radio observation of GRBs 250702B,C,E / EP250702a with the Allen Telescope Array
  50. GRB 250704B: Insight-HXMT detection
  51. Konus-Wind detection of GRB 250703A
  52. IPN triangulation of GRB 250703A
  53. EP250704a/GRB 250704B: GSP observations of the optical counterpart
  54. EP250704a/GRB 250704B: FTW optical and NIR observations of the counterpart
  55. GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  56. Konus-Wind detection of short/hard GRB 250704B/ EP250704a
  57. EP250704a / GRB 250704B: NOT observations of the optical afterglow
  58. EP250704a/GRB 250704B VLT/HAWK-I NIR afterglow detection
  59. GRB 250702F: Kilonova-Catcher optical afterglow detection
  60. GRB 250702F: Monte Agliale Observatory optical observations
  61. GRB250702F: afterglow detected by joint EP-ZTF shadowing program
  62. EP250704a / GRB 250704B: VLT/X-shooter spectroscopic redshift z = 0.661
  63. EP250704a / GRB 250704B: JinShan optical observations
  64. GRB 250704A: SVOM/VT optical observation
  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. EP250704a / GRB 250704B: SVOM/VT optical blue counterpart
  69. EP250704a / GRB 250704B: Pan-STARRS iz-band imaging and photometry
  70. EP 250704a: BOOTES-5 optical detection
  71. EP250704a: refined analysis of the EP-WXT and FXT follow-up observations
  72. LIGO/Virgo/KAGRA S250704ab: Upper limits from Fermi-GBM Observations
  73. GRB 250702A: Insight-HXMT detection
  74. GRB 250704A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 1.091
  75. GRBs 250702B/C/D/E / EP250702a: Swift/UVOT Upper Limits
  76. EP250704a / GRB250704B: Swift-XRT counterpart detection
  77. GRB 250704A: Swift-XRT afterglow detection
  78. GRB 250702B / EP2050702a: FTW optical and NIR observations
  79. Konus-Wind detection of GRB 250702F
  80. EP250704a / GRB 250704B - REM observations
  81. GRB 250702F: GROWTH-India Telescope optical observations
  82. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  83. GRB 250704A: REM retraction of optical afterglow detection and updated limit
  84. EP250702a: WFST optical observations
  85. EP250704a: COLIBRÍ optical counterpart candidate
  86. EP250704a: Einstein Probe detection of an X-ray transient
  87. GRB 250702F: optical photometry from Konkoly
  88. GRB 250704A: REM detection of the optical afterglow
  89. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  90. GRB 250702F: SVOM/VT optical observation
  91. LIGO/Virgo/KAGRA S250704ab: Identification of a GW compact binary merger candidate
  92. GRB 250702F: Swift/UVOT Detection
  93. GRB 250702A: CALET Gamma-Ray Burst Monitor detection
  94. Fermi GBM Analysis of GRB 250702B (formerly B,D,E); dissociation of C burst
  95. Fermi GRB 250703A: Global MASTER-Net observations report
  96. GRBs 250702B,C,D,E / EP250702a: 2.2m CAHA optical upper limit
  97. GRB 250702F: Fermi GBM Observation
  98. GRB 250702F: Leavitt Observatory optical observations
  99. GRB 250702F: AKO Optical Afterglow Detection
  100. GRBs 250702B,C,D,E / EP250702a: VLT/HAWK-I NIR candidate

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