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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"

39267 results found.

  1. Konus-Wind detection of GRB 251118C (EP251118a)
  2. GRB 251117A: Insight-HXMT/HE detection
  3. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  4. GRB 251116D: SVOM/GRM observation of a long GRB
  5. GRB 251119A: SVOM detection of a possible burst
  6. EP251118a: NOT spectroscopic redshift of z = 1.216
  7. EP251118a: Global MASTER-Net observations report
  8. LAT GRB251118.86: Global MASTER-Net observations report
  9. GRB 251118A: Fermi-LAT detection
  10. GRB 251118A: Swift ToO observations
  11. Fermi GRB 251118B: Global MASTER-Net observations report
  12. GRB 251118B: Fermi GBM Final Real-time Localization
  13. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  14. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  15. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  16. GRB 251118A: Fermi GBM Final Real-time Localization
  17. GRB 251116C: SVOM/ECLAIRs refined analysis
  18. GRB 251116B: SVOM/ECLAIRs refined analysis
  19. GRB 251117A: AstroSat CZTI detection
  20. GRB 251114B: Insight-HXMT/HE detection
  21. GRB 251114B: GECAM-B detection of a short burst
  22. GRB 251117A: Fermi GBM observation
  23. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  24. GRB 251116D: Insight-HXMT/HE detection
  25. GRB 251115A: Swift-XRT observations
  26. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  27. GRB 251117A: SVOM/GRM observation of a short burst
  28. GRB 251117A: Tiled Swift observations
  29. GRB 251117A: Fermi-LAT detection
  30. LAT GRB251117.51: Global MASTER-Net observations report
  31. GRB 251116C: Swift/BAT arcminute localization of a burst
  32. GRB 251116B: SVOM/VT optical upper limit
  33. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  34. GRB 251116C: Swift-XRT observations
  35. GRB 251117A: Fermi GBM Final Localization Correction
  36. GRB 251116D: Glowbug gamma-ray detection
  37. EP251023a: Assy AZT-20 optical observations
  38. EP251023a: UAFO and AbAO optical observations
  39. GRB 251116D: AstroSat CZTI detection
  40. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  41. GRB 251116C: SVOM/VT optical upper limit
  42. GRB 251025B: further Mondy optical observations
  43. GRB 251111A: Mondy optical upper limit
  44. GRB 251116B: EP-FXT follow-up observation
  45. GRB 251116B: LCO optical upper limits
  46. GRB 251116C: LCO optical upper limits
  47. SVOM GRB251116C: Global MASTER-Net observations report
  48. GRB 251116C: SVOM detection of a burst
  49. GRB 251116B: SVOM detection of a burst
  50. GRB 251116A: Fermi GBM Final Real-time Localization
  51. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  52. GRB 251115A: Tiled Swift observations
  53. GRB 251115A: Fermi-LAT detection
  54. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  55. Fermi GRB 251115A: Global MASTER-Net observations report
  56. GRB 251115A: Fermi GBM Final Real-time Localization
  57. GRB 251113A: Glowbug gamma-ray detection
  58. GRB 251113A: AstroSat CZTI detection
  59. GRB 251114B: Fermi GBM Final Real-time Localization
  60. GRB 251112A: Swift-BAT refined analysis
  61. Konus-Wind detection of GRB 251108C
  62. Fermi trigger No 784717756: Global MASTER-Net observations report
  63. Konus-Wind detection of GRB 251103A
  64. IPN triangulation of GRB 251108C
  65. Fermi GRB 251114A: Global MASTER-Net observations report
  66. GRB 251114A: Fermi GBM Final Real-time Localization
  67. Fermi GRB 251113A: Global MASTER-Net observations report
  68. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  69. GRB 251113A: Fermi GBM Final Real-time Localization
  70. GRB 251111A: SVOM/ECLAIRs refined analysis
  71. GRB 251025B: SVOM/ECLAIRs refined analysis
  72. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  73. GRB 251112A: Swift/UVOT Upper Limits
  74. GRB 251112A: Swift-XRT refined Analysis
  75. GRB 251108C: AstroSat CZTI detection
  76. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  77. GRB 251112B: MAXI/GSC detection
  78. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  79. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  80. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  81. GRB 251108B: Glowbug gamma-ray detection
  82. Swift Trigger 1413695: a possible GRB 251112A
  83. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  84. Fermi trigger No 784621743: Global MASTER-Net observations report
  85. Fermi Gamma-ray Burst Monitor trigger 784653403/251112637 is not a GRB
  86. GRB251111A: 1.3m DFOT optical upper limit
  87. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  88. GRB 251111A: Swift-XRT afterglow detection
  89. GRB 251111A: SVOM/VT optical observations with X-band data
  90. SVOM GRB251111.42: Global MASTER-Net observations report
  91. GRB 251111A: Swift-XRT observations
  92. SVOM GRB251111.22: Global MASTER-Net observations report
  93. GRB 251111A: EP-FXT counterpart detection
  94. GRB 251013C: Chandra X-ray observations and jet break detection
  95. GRB 251111A: SVOM/VT optical observations with VHF data
  96. GRB 251111A: KAIT optical upper limit
  97. GRB 251111A: LCO optical observation
  98. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  99. GRB 251111A: SVOM detection of a soft burst
  100. GRB 251103B: Swift-BAT refined analysis

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