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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"

39243 results found.

  1. GRB 251115A: Swift-XRT observations
  2. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  3. GRB 251117A: SVOM/GRM observation of a short burst
  4. GRB 251117A: Tiled Swift observations
  5. GRB 251117A: Fermi-LAT detection
  6. LAT GRB251117.51: Global MASTER-Net observations report
  7. GRB 251116C: Swift/BAT arcminute localization of a burst
  8. GRB 251116B: SVOM/VT optical upper limit
  9. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  10. GRB 251116C: Swift-XRT observations
  11. GRB 251117A: Fermi GBM Final Localization Correction
  12. GRB 251116D: Glowbug gamma-ray detection
  13. EP251023a: Assy AZT-20 optical observations
  14. EP251023a: UAFO and AbAO optical observations
  15. GRB 251116D: AstroSat CZTI detection
  16. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  17. GRB 251116C: SVOM/VT optical upper limit
  18. GRB 251025B: further Mondy optical observations
  19. GRB 251111A: Mondy optical upper limit
  20. GRB 251116B: EP-FXT follow-up observation
  21. GRB 251116B: LCO optical upper limits
  22. GRB 251116C: LCO optical upper limits
  23. SVOM GRB251116C: Global MASTER-Net observations report
  24. GRB 251116C: SVOM detection of a burst
  25. GRB 251116B: SVOM detection of a burst
  26. GRB 251116A: Fermi GBM Final Real-time Localization
  27. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  28. GRB 251115A: Tiled Swift observations
  29. GRB 251115A: Fermi-LAT detection
  30. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  31. Fermi GRB 251115A: Global MASTER-Net observations report
  32. GRB 251115A: Fermi GBM Final Real-time Localization
  33. GRB 251113A: Glowbug gamma-ray detection
  34. GRB 251113A: AstroSat CZTI detection
  35. GRB 251114B: Fermi GBM Final Real-time Localization
  36. GRB 251112A: Swift-BAT refined analysis
  37. Konus-Wind detection of GRB 251108C
  38. Fermi trigger No 784717756: Global MASTER-Net observations report
  39. Konus-Wind detection of GRB 251103A
  40. IPN triangulation of GRB 251108C
  41. Fermi GRB 251114A: Global MASTER-Net observations report
  42. GRB 251114A: Fermi GBM Final Real-time Localization
  43. Fermi GRB 251113A: Global MASTER-Net observations report
  44. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  45. GRB 251113A: Fermi GBM Final Real-time Localization
  46. GRB 251111A: SVOM/ECLAIRs refined analysis
  47. GRB 251025B: SVOM/ECLAIRs refined analysis
  48. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  49. GRB 251112A: Swift/UVOT Upper Limits
  50. GRB 251112A: Swift-XRT refined Analysis
  51. GRB 251108C: AstroSat CZTI detection
  52. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  53. GRB 251112B: MAXI/GSC detection
  54. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  55. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  56. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  57. GRB 251108B: Glowbug gamma-ray detection
  58. Swift Trigger 1413695: a possible GRB 251112A
  59. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  60. Fermi trigger No 784621743: Global MASTER-Net observations report
  61. Fermi Gamma-ray Burst Monitor trigger 784653403/251112637 is not a GRB
  62. GRB251111A: 1.3m DFOT optical upper limit
  63. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  64. GRB 251111A: Swift-XRT afterglow detection
  65. GRB 251111A: SVOM/VT optical observations with X-band data
  66. SVOM GRB251111.42: Global MASTER-Net observations report
  67. GRB 251111A: Swift-XRT observations
  68. SVOM GRB251111.22: Global MASTER-Net observations report
  69. GRB 251111A: EP-FXT counterpart detection
  70. GRB 251013C: Chandra X-ray observations and jet break detection
  71. GRB 251111A: SVOM/VT optical observations with VHF data
  72. GRB 251111A: KAIT optical upper limit
  73. GRB 251111A: LCO optical observation
  74. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  75. GRB 251111A: SVOM detection of a soft burst
  76. GRB 251103B: Swift-BAT refined analysis
  77. GRB 251106A: Swift/UVOT Upper Limits
  78. GRB 251105B: Insight-HXMT/HE detection
  79. GRB 251106B: Insight-HXMT detection
  80. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  81. GRB 251105A: AstroSat CZTI detection
  82. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  83. GRB 251108A: Fermi GBM Final Localization Correction
  84. Fermi trigger No 784329591: Global MASTER-Net observations report
  85. Fermi trigger No 784279167: Global MASTER-Net observations report
  86. SVOM GRB251108.54: Global MASTER-Net observations report
  87. GRB 251102B: SVOM/GRM observation
  88. Fermi Gamma-ray Burst Monitor trigger 784279167/251108305 is not a GRB
  89. SVOM GRB251106.83: Global MASTER-Net observations report
  90. IPN triangulation of GRB 251105B (possible sGRB with EE)
  91. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  92. GRB 251106B: SVOM/GRM observation of a short burst
  93. GRB 251106A: Swift-XRT afterglow detection
  94. GRB 251106A: Kilonova-Catcher optical upper limit
  95. Fermi GBM Sub-Threshold Detection of GRB 251106A
  96. GRB 251106A: Swift/BAT arcminute localization of a burst
  97. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  98. GRB 251106A: MASTER optical observations
  99. GRB 251106A: SVOM detection of a burst
  100. GRB 251103B: AstroSat CZTI detection

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