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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.

"N/A_MC170219_R1" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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').
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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"

10959 results found.

  1. GRB 250706B/C: VLT/X-shooter redshift z = 0.942
  2. GRB 250706B/C: Fermi-LAT detection
  3. EP250702a/GRB250702 B,D,E: GRANDMA Upper Limit
  4. GRB 250702F: GRANDMA observations
  5. IceCube-250706A: COLIBRÍ optical upper limits
  6. GRB 250706B: SVOM/VT optical observation
  7. GRB 250703A: EIRSAT-1 GMOD Detection
  8. EP250704a / GRB 250704B: VLT/X-shooter spectroscopic redshift z = 0.661
  9. GRB 250704A: SVOM/VT optical observation
  10. GRB 250704A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 1.091
  11. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  12. GRB 250704A: SVOM detection of a burst
  13. GRB 250702F: Swift/UVOT Detection
  14. GRB 250702A: CALET Gamma-Ray Burst Monitor detection
  15. GRB 250702F: Fermi GBM Observation
  16. GRB 250424A: VIRT Optical Upper Limit
  17. EP250702a/GRB 250702B, C, D, E: EP-FXT follow-up observation
  18. GRB 250702B,C,D,E / EP 250702a: MAXI/GSC detection
  19. GRB 250702F: COLIBRÍ Observations of the Afterglow
  20. GRB 250702F: GTC/OSIRIS+ spectroscopic redshift z = 1.520
  21. GRB 250702F: NOT observations of the optical afterglow
  22. GRB 250702F: Swift detection of a burst with an optical counterpart
  23. GRB 250628B: SVOM/VT optical upper limit
  24. GRB 250628A: VLT/X-shooter upper limits
  25. GRB 250625A: AbAO and INASAN Kislovodsk Optical Observations
  26. GRB 250625A: GTC/OSIRIS+ spectroscopic observations of the potential host galaxy
  27. GRB 250625A: Fermi-LAT detection
  28. GRB 250617B: Mondy and SAO RAS optical observations on 2025-06-23, 2025-06-24
  29. GRB 241018A: Maidanak optical observations
  30. sb25061207/GRB 250612D - SVOM/ECLAIRs refined analysis
  31. GRB 250521A: VZLUSAT-2 detection
  32. GRB 250617B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  33. GRB 250617B: Assy AZT-20 Optical Observations
  34. SVOM sb25061207: AbAO AS-32 Optical Upper Limit
  35. sb25061207: EP-FXT follow-up observation and afterglow candidate
  36. EP250612a / GRB 250612B: SVOM/VT optical candidate
  37. sb25061218: SVOM detection of a X-ray transient
  38. sb25061207: SVOM/VT optical counterpart
  39. sb25061207: SVOM detection of a X-ray transient
  40. GRB 250610B: SVOM/VT optical shallow decay
  41. GRB 250610B: SVOM/GRM analysis
  42. GRB 250610B: EP-FXT follow-up observation and afterglow counterpart
  43. GRB 250610B: SVOM/VT optical counterpart
  44. GRB 250610B: SVOM detection of a long burst
  45. EP250610a: SVOM/VT optical upper limit
  46. GRBAlpha reentry on June 9, 2025
  47. The EP-WXT trigger 01709178283 is likely a flaring star
  48. GRB 250527C: CrAO Optical Upper Limit
  49. GRB 250605A: SVOM/VT optical upper limit
  50. GRB 250605A: Swift detection of a burst
  51. GRB 250601A: PRIME H band upper limit.
  52. GRB 250601A: PRIME J band upper limit.
  53. GRB 250602A: Fermi-LAT detection
  54. GRB 250530A: VLT/HAWK-I NIR counterpart fading
  55. EP#01709177494: SVOM/VT optical observations
  56. GRB 250530A: SVOM/VT optical upper limit
  57. GRB 250527D: CALET Gamma-Ray Burst Monitor detection
  58. GRB 250527C: Swift/UVOT Upper Limits
  59. GRB 250521C (short): Zwicky Transient Facility identification of a possible fast optical transient counterpart
  60. EP250526a: SVOM/VT optical upper limit
  61. GRB 250527B / MAXI J1450-527 : MAXI/GSC detection
  62. GRB 250521A: GRBAlpha detection
  63. GRB 250520A: GRBAlpha detection
  64. The EP-WXT trigger 01709176612: SVOM/VT optical observations
  65. GRB 250521B: EP-FXT follow-up observation and afterglow candidates
  66. GRB 250521D: SVOM/VT optical observations
  67. GRB 250520A: CALET Gamma-Ray Burst Monitor detection
  68. GRB 250521B: SVOM detection of a burst through offline search
  69. IPN triangulation of GRB 250516B
  70. GRB 250520A：SVOM/VT optical candidate
  71. GRB 250516B: GRBAlpha detection
  72. GRB 250520A: Swift detection of a burst
  73. GRB 250515A: NOT classification of GOTO25cqo as a type-Ia SN
  74. GRB 250515A/GOTO25cqo: SVOM/VT optical blue color
  75. EP250511a: Koshka Zeiss-1000 Optical Upper Limit
  76. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  77. GRB 250512B/EP250512a: SVOM/VT optical fading
  78. GRB 250512B/EP250512a：SVOM/VT bright optical counterpart
  79. GRB 250507B: GRBAlpha detection
  80. GRB 250506A: GRBAlpha detection
  81. EP250511a: SVOM/VT optical candidate comfirmation
  82. EP250508a: SVOM/VT optical candidate fading
  83. GRB 250506A: NOT optical upper limits
  84. EP250508a: SVOM/VT optical candidate
  85. GRB 250506A: SVOM/VT optical upper limit
  86. GRB 250506A: Swift/UVOT Upper Limits
  87. GRB 250427B : SVOM detection of a burst through offline search
  88. GRB 250507A: SVOM/VT optical upper limit
  89. GRB 250504A: VLT/X-shooter upper limits
  90. GRB 250504A: SVOM/VT upper limit
  91. GRB 250502A: Mondy and Tien-Shan Optical Observations
  92. GRB 250502A: Montarrenti Observatory optical detection
  93. GRB 250502A: NOT optical observations
  94. GRB 250502A: Redshift from OSIRIS+/GTC z = 2.163
  95. GRB 250407A: VZLUSAT-2 detection
  96. GRB 250430A : MITSuME Akeno optical upper limits
  97. GRB 250430A / EP250430a: VLT/X-shooter spectroscopic redshift z = 0.767
  98. GRB 250424A: CALET Gamma-Ray Burst Monitor detection
  99. GRB 250430A: Swift detection of a burst with optical counterpart
  100. EP250427a: Lesedi optical counterpart detection

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