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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"

32554 results found.

  1. GRB 250704B / EP250704a: VLA radio detection
  2. Fermi GRB 250708A: Global MASTER-Net observations report
  3. IceCube-250706A: Upper limits from a search for additional neutrino events in IceCube
  4. LIGO/Virgo/KAGRA S250705cb: Updated Sky localization
  5. LIGO/Virgo/KAGRA S250704ab: Updated Sky localization and EM Bright Classification
  6. LIGO/Virgo/KAGRA S250702n: Updated Sky localization
  7. LIGO/Virgo/KAGRA S250701bq: Updated Sky localization
  8. EP250704a/GRB250704B : HCT optical and NIR upper limits
  9. LIGO/Virgo/KAGRA S250701bp: Updated Sky localization
  10. GRB 250706B/C: Konus-Wind analysis of the prompt emission
  11. GRB 250706B: SVOM observations interpreted as the afterglow of GRB 250706C
  12. GRB 250704B: CALET Gamma-Ray Burst Monitor detection
  13. GRB 250704B / EP250704a: Mondy and AbAO optical observations
  14. GRB 250702F: radio detection with the VLA
  15. GRB 250706B/C: VLT/X-shooter redshift z = 0.942
  16. IceCube-250706A: EP-FXT follow-up observations
  17. Fermi-LAT Gamma-ray Observations of IceCube-250706A
  18. GRB 250706B/C: Fermi-LAT detection
  19. GRB 250704A: SVOM/COLIBRÍ (FM-GFT) optical observations
  20. EP250702a/GRB250702 B,D,E: GRANDMA Upper Limit
  21. GRB 250706B: Swift/UVOT Detection
  22. EP250702a/ GRB 250702B: NuSTAR X-ray Observations
  23. GRB 250706C: Konus-Wind detection of a very bright GRB ~1200 s before GRB 250706B
  24. GRB 250704A: Swift/BAT-GUANO localization skymap of a burst
  25. GRB 250702F: GRANDMA observations
  26. GRB 250706B: refined SVOM/MXT data analysis
  27. GRB 250706A: Swift/UVOT Upper Limits
  28. GRB 250706B: REM optical observations
  29. GRB 250706A: REM optical/NIR observations
  30. EP250706a/GRB 250706A: EP-WXT detection of a fast X-ray transient
  31. IceCube-250416A: DDOTI Optical Upper Limit
  32. IceCube-250706A: COLIBRÍ optical upper limits
  33. Swift GRB 250706A: Global MASTER-Net observations report
  34. GRB 250706A: JinShan optical upper limits
  35. GRB 250706A: SAO RAS optical observations
  36. EP250704A: NOWT Detection
  37. GRB 250706A: SVOM/C-GFT upper limit in eary phase
  38. GRB250706B: Swift-XRT counterpart detection
  39. GRB 250706B: iTelescope optical observations
  40. EP250704a / GRB 250704B: end of optical plateau phase and rapid fading of the counterpart
  41. GRB 250706B: SVOM/VT optical observation
  42. GRB 250706B: TRT bright optical counterpart detection
  43. GRB 250706A: GROWTH-India Telescope optical upper limit
  44. GRBs 250702B,C,D,E / EP250702a: J band upper limit by SYSU 80cm infrared telescope
  45. EP250702a/GRB250702 B,E,D: MeerKAT radio counterpart
  46. GRB 250703A: EIRSAT-1 GMOD Detection
  47. EP250702a/GRB 250702B,C,D,E: Archival radio observations from ASKAP VAST
  48. GRB 250704B: Swift/UVOT Upper Limits
  49. GRB 250704A: Swift/UVOT Detection
  50. LIGO/Virgo/KAGRA S250705cb: Identification of a GW compact binary merger candidate
  51. Radio observation of GRBs 250702B,C,E / EP250702a with the Allen Telescope Array
  52. GRB 250704B: Insight-HXMT detection
  53. Konus-Wind detection of GRB 250703A
  54. IPN triangulation of GRB 250703A
  55. EP250704a/GRB 250704B: GSP observations of the optical counterpart
  56. EP250704a/GRB 250704B: FTW optical and NIR observations of the counterpart
  57. GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  58. Konus-Wind detection of short/hard GRB 250704B/ EP250704a
  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: VLT/X-shooter spectroscopic redshift z = 0.661
  65. EP250704a / GRB 250704B: JinShan optical observations
  66. GRB 250704A: SVOM/VT optical observation
  67. EP250704a / GRB 250704B: SAO RAS optical observations
  68. EP250704a / GRB 250704B : GROWTH-India Telescope optical observations
  69. GRBs 250702B,D,E / EP250702a: fast fading, extremely red counterpart
  70. EP250704a / GRB 250704B: SVOM/VT optical blue counterpart
  71. EP250704a / GRB 250704B: Pan-STARRS iz-band imaging and photometry
  72. EP 250704a: BOOTES-5 optical detection
  73. EP250704a: refined analysis of the EP-WXT and FXT follow-up observations
  74. LIGO/Virgo/KAGRA S250704ab: Upper limits from Fermi-GBM Observations
  75. GRB 250702A: Insight-HXMT detection
  76. GRB 250704A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 1.091
  77. GRBs 250702B/C/D/E / EP250702a: Swift/UVOT Upper Limits
  78. EP250704a / GRB250704B: Swift-XRT counterpart detection
  79. GRB 250704A: Swift-XRT afterglow detection
  80. GRB 250702B / EP2050702a: FTW optical and NIR observations
  81. Konus-Wind detection of GRB 250702F
  82. EP250704a / GRB 250704B - REM observations
  83. GRB 250702F: GROWTH-India Telescope optical observations
  84. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  85. GRB 250704A: REM retraction of optical afterglow detection and updated limit
  86. EP250702a: WFST optical observations
  87. EP250704a: COLIBRÍ optical counterpart candidate
  88. EP250704a: Einstein Probe detection of an X-ray transient
  89. GRB 250702F: optical photometry from Konkoly
  90. GRB 250704A: REM detection of the optical afterglow
  91. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  92. GRB 250702F: SVOM/VT optical observation
  93. LIGO/Virgo/KAGRA S250704ab: Identification of a GW compact binary merger candidate
  94. GRB 250702F: Swift/UVOT Detection
  95. GRB 250702A: CALET Gamma-Ray Burst Monitor detection
  96. Fermi GBM Analysis of GRB 250702B (formerly B,D,E); dissociation of C burst
  97. Fermi GRB 250703A: Global MASTER-Net observations report
  98. GRBs 250702B,C,D,E / EP250702a: 2.2m CAHA optical upper limit
  99. GRB 250702F: Fermi GBM Observation
  100. GRB 250702F: Leavitt Observatory optical observations

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