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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"

36011 results found.

  1. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  2. GRB 251122A/EP251122a: SVOM/C-GFT upper limit
  3. GRB 251122A / EP251122a: SVOM detection of a long burst
  4. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  5. GRB 251121A: Glowbug gamma-ray detection of a likely short burst
  6. EP251118a: Xinglong-2.16m optical observation
  7. GRB 251115A: Fermi GBM Observation
  8. GRB 251121A: Fermi GBM Final Real-time Localization
  9. Fermi Gamma-ray Burst Monitor trigger 785388351 / 251121143 is not a GRB
  10. GRB 251118A: Swift/UVOT Detection
  11. EP251118a / GRB 251118C: SAO RAS optical observations
  12. GRB 251118A: Glowbug gamma-ray detection
  13. GRB 251118A: Fermi GBM Observation
  14. GRB 251118A: Swift-XRT afterglow detection
  15. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  16. GRB 251118A: GECAM-B detection
  17. EP251118a / GRB 251118C: SVOM/VT optical observation
  18. GRB 251118A: NuSTAR detection of bright prompt emission
  19. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  20. GRB 251116C: NOT optical observations
  21. GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
  22. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  23. GRB 251018A: FRAM-Auger optical detection
  24. GRB 251117A: Swift-XRT observations
  25. EP251118A / GRB 251118C : MASTER optical counterpart observations
  26. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  27. Konus-Wind detection of GRB 251118C (EP251118a)
  28. GRB 251117A: Insight-HXMT/HE detection
  29. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  30. GRB 251116D: SVOM/GRM observation of a long GRB
  31. GRB 251119A: SVOM detection of a possible burst
  32. EP251118a: NOT spectroscopic redshift of z = 1.216
  33. GRB 251118A: Fermi-LAT detection
  34. GRB 251118A: Swift ToO observations
  35. Fermi GRB 251118B: Global MASTER-Net observations report
  36. GRB 251118B: Fermi GBM Final Real-time Localization
  37. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  38. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  39. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  40. GRB 251118A: Fermi GBM Final Real-time Localization
  41. GRB 251116C: SVOM/ECLAIRs refined analysis
  42. GRB 251116B: SVOM/ECLAIRs refined analysis
  43. GRB 251117A: AstroSat CZTI detection
  44. GRB 251114B: Insight-HXMT/HE detection
  45. GRB 251114B: GECAM-B detection of a short burst
  46. GRB 251117A: Fermi GBM observation
  47. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  48. GRB 251116D: Insight-HXMT/HE detection
  49. GRB 251115A: Swift-XRT observations
  50. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  51. GRB 251117A: SVOM/GRM observation of a short burst
  52. GRB 251117A: Tiled Swift observations
  53. GRB 251117A: Fermi-LAT detection
  54. GRB 251116C: Swift/BAT arcminute localization of a burst
  55. GRB 251116B: SVOM/VT optical upper limit
  56. GRB 251116C: Swift-XRT observations
  57. GRB 251117A: Fermi GBM Final Localization Correction
  58. GRB 251116D: Glowbug gamma-ray detection
  59. EP251023a: Assy AZT-20 optical observations
  60. EP251023a: UAFO and AbAO optical observations
  61. GRB 251116D: AstroSat CZTI detection
  62. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  63. GRB 251116C: SVOM/VT optical upper limit
  64. GRB 251025B: further Mondy optical observations
  65. GRB 251111A: Mondy optical upper limit
  66. GRB 251116B: EP-FXT follow-up observation
  67. GRB 251116B: LCO optical upper limits
  68. GRB 251116C: LCO optical upper limits
  69. GRB 251116C: SVOM detection of a burst
  70. GRB 251116B: SVOM detection of a burst
  71. GRB 251116A: Fermi GBM Final Real-time Localization
  72. GRB 251115A: Tiled Swift observations
  73. GRB 251115A: Fermi-LAT detection
  74. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  75. Fermi GRB 251115A: Global MASTER-Net observations report
  76. GRB 251115A: Fermi GBM Final Real-time Localization
  77. GRB 251113A: Glowbug gamma-ray detection
  78. GRB 251113A: AstroSat CZTI detection
  79. GRB 251114B: Fermi GBM Final Real-time Localization
  80. GRB 251112A: Swift-BAT refined analysis
  81. Konus-Wind detection of GRB 251108C
  82. Konus-Wind detection of GRB 251103A
  83. IPN triangulation of GRB 251108C
  84. Fermi GRB 251114A: Global MASTER-Net observations report
  85. GRB 251114A: Fermi GBM Final Real-time Localization
  86. Fermi GRB 251113A: Global MASTER-Net observations report
  87. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  88. GRB 251113A: Fermi GBM Final Real-time Localization
  89. GRB 251111A: SVOM/ECLAIRs refined analysis
  90. GRB 251025B: SVOM/ECLAIRs refined analysis
  91. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  92. GRB 251112A: Swift/UVOT Upper Limits
  93. GRB 251112A: Swift-XRT refined Analysis
  94. GRB 251108C: AstroSat CZTI detection
  95. GRB 251112B: MAXI/GSC detection
  96. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  97. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  98. GRB 251108B: Glowbug gamma-ray detection
  99. Swift Trigger 1413695: a possible GRB 251112A
  100. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations

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