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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.

Advanced Search Examples (click to copy):

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

32716 results found.

  1. GRB 251013C: BOOTES-6 early optical detection
  2. GRB 251013C: SVOM/VT optical observation
  3. GRB 251013C: SVOM detection of a burst
  4. LIGO/Virgo/KAGRA S251013x: Updated Sky localization and Source Classification
  5. GRB 251013B: SVOM/GRM observation
  6. GRB 251013A: SVOM/GRM observation
  7. GRB 251003A: Mondy optical upper limit
  8. MASTER OT J011025.98-583210.6 : SVOM/VT optical observation
  9. Fermi GRB 251013A: Global MASTER-Net observations report
  10. LIGO/Virgo/KAGRA S251013x: Identification of a GW compact binary merger candidate
  11. GRB 251011B inspection: MASTER orphan GRB detection
  12. GRB 251011A: Insight-HXMT detection
  13. GRB 251011B: Swift/UVOT Upper Limits
  14. Fermi GRB 251011A: Global MASTER-Net observations report
  15. GRB 251011B: SVOM/GRM observation
  16. GRB 251011B: Fermi GBM Observation
  17. GRB 251011B : MASTER optical observations
  18. GRB 251010A: AstroSat CZTI detection
  19. GRB 251011A: AstroSat CZTI detection
  20. GRB 251009B: SVOM/GRM observation of short GRB
  21. GRB 251007B: Swift/UVOT Upper Limits
  22. GRB251007A: Swift/UVOT Detection
  23. GRB 251009A: GECAM-B detection of a short burst
  24. GRB 251009A: Insight-HXMT detection of a short burst
  25. GRB 251009B (short): Glowbug gamma-ray detection
  26. GRB 251007A: Swift-BAT refined analysis
  27. GRB 251009A: SVOM/GRM observation of short GRB with possible tail emission
  28. GRB 251007A: SVOM/GRM observation
  29. GRB 251007A: Insight-HXMT detection
  30. GRB 251006A: CALET Gamma-Ray Burst Monitor detection
  31. GRB 251007B - SVOM/ECLAIRs refined analysis
  32. GRB 250916A: TERI Gamma-ray detection
  33. GRB 250919A: TERI gamma-ray detection
  34. EP251006a: Global MASTER-Net observations report
  35. GRB 251006A: Fermi GBM Observation
  36. GRB 251002A - SVOM/ECLAIRs refined analysis
  37. GRB 251003A: Fermi GBM Observation
  38. GRB 251006B: Fermi GBM Observation
  39. GRB 251007B: COLIBRÍ optical upper limit
  40. GRB 251007A: AstroSat CZTI detection
  41. GRB 251006B/EP251006a: EP-FXT afterglow detection
  42. GRB 250917B: iTelescope T-26 upper limit
  43. EP250911a: Koshka Zeiss-1000 Optical Upper Limit
  44. GRB 251007B: SVOM/VT optical candidate
  45. GRB 251007A: NOT optical observations
  46. GRB 251007A: AKO Optical Upper Limit
  47. GRB 251007A: CALET Gamma-Ray Burst Monitor detection
  48. GRB 251006B: Insight-HXMT detection
  49. GRB 251007A: SVOM/C-GFT optical observations
  50. GRB 251005C: PRIME J-band upper limit
  51. Swift GRB 251007B: Global MASTER-Net observations report
  52. GRB 251007A: Glowbug gamma-ray detection
  53. GRB 251007B: SVOM/C-GFT upper limit
  54. Swift GRB 251007A: Global MASTER-Net observations report
  55. GRB 251007B: SVOM detection of a faint burst
  56. GRB 251006A: Swift/BAT-GUANO subthreshold detection of a short burst
  57. GRB 251005B: Glowbug gamma-ray detection
  58. EP251003a: LCO and VST fading optical counterpart
  59. GRB 251006B/EP251006a: SVOM/VT optical candidate
  60. GRB 251006B/EP251006a: EP-FXT follow-up observation
  61. GRB 251006B: SVOM/GRM observation
  62. GRB 251006B: COLIBRÍ optical upper limit
  63. GRB 251006B/EP251006a: EP-WXT detection
  64. GRB 251005C: SVOM/VT optical fading
  65. GRB 251005C: SVOM/GRM observation of a likely short GRB
  66. LIGO/Virgo/KAGRA S251006dd: Identification of a GW compact binary merger candidate
  67. Fermi GRB 251006B: Global MASTER-Net observations report
  68. GRB 251006A (short): Glowbug gamma-ray detection
  69. GRB 251005C: COLIBRÍ optical observations
  70. Fermi GRB 251006A: Global MASTER-Net observations report
  71. GRB 251005C: VLT/X-shooter Imaging
  72. GRB 251003A: LAST optical observations
  73. GRB 251002A: LAST optical observations
  74. GRB 251005C: SVOM/VT optical candidate
  75. GRB 251005C: AstroSat CZTI detection
  76. GRB 251005C: Swift/UVOT Upper Limits
  77. GRB 250902A: MSU cubesats detection
  78. GRB 251005C: Fermi GBM Observation
  79. Swift GRB 251005A: Global MASTER-Net observations report
  80. GRB 251005C: GOTO optical upper limits
  81. GRB 251002A: Mondy/AZT-33IK optical observations
  82. GRB 251002A: Insight-HXMT detection
  83. GRB 251002A: Insight-HXMT detection
  84. GRB 251003A: J-band detection with WINTER
  85. GRB 251002A: NIR observations with WINTER
  86. Fermi GBM Sub-Threshold Detection of GRB 250910A
  87. GRB 251003A: Swift-BAT refined analysis
  88. GRB 251001B: NIR observations with WINTER
  89. GRB 251002A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  90. GRB 251003A: Swift/UVOT Upper Limits
  91. GRB 251002A: Swift/UVOT detection
  92. GRB 251001A: AstroSat CZTI detection
  93. GRB 251001B: COLIBRÍ further observations and evidence of a multi-wavelength shallow decay
  94. GRB 251003A: COLIBRÍ photometric redshift
  95. GRB 251003A: GOTO detection of the optical counterpart
  96. GRB 251002A: Fermi GBM Observation
  97. GRB 251002A: GOTO detection of optical counterpart
  98. GRB 251001C: SVOM/GRM observation
  99. EP250821a: iTelescope T-59 possible detection of the optical counterpart
  100. GRB 251002A: AKO Early Optical Afterglow Detection

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