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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"

29109 results found.

  1. SVOM GRB251116C: Global MASTER-Net observations report
  2. GRB 251116C: SVOM detection of a burst
  3. GRB 251116B: SVOM detection of a burst
  4. GRB 251116A: Fermi GBM Final Real-time Localization
  5. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  6. GRB 251115A: Tiled Swift observations
  7. GRB 251115A: Fermi-LAT detection
  8. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  9. Fermi GRB 251115A: Global MASTER-Net observations report
  10. GRB 251115A: Fermi GBM Final Real-time Localization
  11. GRB 251113A: Glowbug gamma-ray detection
  12. GRB 251113A: AstroSat CZTI detection
  13. GRB 251114B: Fermi GBM Final Real-time Localization
  14. GRB 251112A: Swift-BAT refined analysis
  15. Fermi trigger No 784717756: Global MASTER-Net observations report
  16. Konus-Wind detection of GRB 251103A
  17. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  18. The EP-WXT trigger 01709248221 is likely a flaring star
  19. Fermi GRB 251114A: Global MASTER-Net observations report
  20. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  21. GRB 251114A: Fermi GBM Final Real-time Localization
  22. Fermi GRB 251113A: Global MASTER-Net observations report
  23. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  24. GRB 251113A: Fermi GBM Final Real-time Localization
  25. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  26. GRB 251112A: Swift/UVOT Upper Limits
  27. GRB 251112A: Swift-XRT refined Analysis
  28. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  29. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  30. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  31. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  32. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  33. Swift Trigger 1413695: a possible GRB 251112A
  34. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  35. Fermi trigger No 784621743: Global MASTER-Net observations report
  36. Fermi Gamma-ray Burst Monitor trigger 784653403/251112637 is not a GRB
  37. GRB251111A: 1.3m DFOT optical upper limit
  38. SVOM GRB251111.42: Global MASTER-Net observations report
  39. GRB 251111A: Swift-XRT observations
  40. SVOM GRB251111.22: Global MASTER-Net observations report
  41. GRB 251111A: EP-FXT counterpart detection
  42. GRB 251013C: Chandra X-ray observations and jet break detection
  43. GRB 251111A: LCO optical observation
  44. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  45. GRB 251111A: SVOM detection of a soft burst
  46. GRB 251103B: Swift-BAT refined analysis
  47. GRB 251106A: Swift/UVOT Upper Limits
  48. GRB 251105B: Insight-HXMT/HE detection
  49. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  50. GRB 251105A: AstroSat CZTI detection
  51. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  52. GRB 251108A: Fermi GBM Final Localization Correction
  53. Fermi trigger No 784329591: Global MASTER-Net observations report
  54. Fermi trigger No 784279167: Global MASTER-Net observations report
  55. SVOM GRB251108.54: Global MASTER-Net observations report
  56. GRB 251102B: SVOM/GRM observation
  57. Fermi Gamma-ray Burst Monitor trigger 784279167/251108305 is not a GRB
  58. The EP-WXT trigger 01709248051 is likely a flaring star
  59. SVOM GRB251106.83: Global MASTER-Net observations report
  60. IPN triangulation of GRB 251105B (possible sGRB with EE)
  61. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  62. GRB 251106B: SVOM/GRM observation of a short burst
  63. GRB 251106A: Kilonova-Catcher optical upper limit
  64. Fermi GBM Sub-Threshold Detection of GRB 251106A
  65. GRB 251106A: Swift/BAT arcminute localization of a burst
  66. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  67. GRB 251106A: MASTER optical observations
  68. GRB 251106A: SVOM detection of a burst
  69. GRB 251103B: AstroSat CZTI detection
  70. GRB 251025C: TERI Gamma-ray detection
  71. GRB 251016B: TERI Gamma-ray detection
  72. GRB 251016A: TERI Gamma-ray detection of a short burst
  73. GRB 250920C: TERI Gamma-ray detection
  74. Fermi trigger No 784034269: Global MASTER-Net observations report
  75. Fermi Gamma-ray Burst Monitor trigger 784109140/251106337 is not a GRB
  76. EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
  77. GRB 251105A: Fermi GBM Observation
  78. GRB 251105C: Fermi GBM Final Localization Correction
  79. LIGO/Virgo/KAGRA S251031dw: Candidates from the Zwicky Transient Facility
  80. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  81. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  82. GRB 251105B: AstroSat CZTI detection of a short burst with extended emission
  83. GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
  84. Fermi GBM Sub-Threshold Detection of GRB 251105B
  85. GRB 251103B: Swift/UVOT Upper Limits
  86. GRB 251105B: SVOM/GRM observation of a possible short burst with extended emission
  87. Fermi GRB 251105A: Global MASTER-Net observations report
  88. GRB 251105A: Fermi GBM Final Real-time Localization
  89. Fermi Gamma-ray Burst Monitor trigger 783986701/251104920 is not a GRB
  90. GRB 251103B: Fermi GBM observation
  91. GRB 251104A: SVOM detection of a burst
  92. GRB 251028A: Insight-HXMT/HE detection
  93. EP251102a: FTW optical and NIR observations
  94. GRB 251103A: WFST optical observations
  95. GRB 251103A: OHP/T193 optical observations
  96. GRB 251103A: Xinglong 2.16m optical detection
  97. GRB 251103A: Insight-HXMT detection
  98. GRB 251103A: KAIT optical observations
  99. GRB 251103B: Nanshan/HMT optical upper limit
  100. GRB 251013C: 7DT detection and Medium-band SED of Afterglow

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