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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"

38579 results found.

  1. Fermi GBM Sub-Threshold Detection of GRB 260914A
  2. GRB 260914A: LCO optical observation
  3. GRB 260914A: SVOM/C-GFT optical observations
  4. GRB 260914A: SVOM/VT optical counterpart confirmation
  5. GRB 260914A: SVOM/VT optical observation from VHF data
  6. GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  7. SVOM GRB260914.47: Global MASTER-Net observations report
  8. GRB 260914A: SVOM detection of a burst
  9. GRB 260913A: SVOM trigger sb26091302 is not an astrophysical event
  10. GRB 260818A: Continued ATCA observations
  11. SVOM GRB260913.32: Global MASTER-Net observations report
  12. GRB 260913A: SVOM/C-GFT optical upper limit
  13. GRB 260913A: SVOM detection of a faint burst
  14. GRB 260909A: OSN 1.5m, CAHA 2.2m and GTC 10.4m optical upper limits
  15. GRB 260907A: SVOM/GRM observation
  16. GRB 260909A: CrAO and AbAO optical upper limits
  17. GRB 260909A: SVOM/ECLAIRs refined analysis
  18. GRB 260910B: GOTO tentative optical counterpart candidates
  19. GRB 260909A: Swift ToO observations
  20. GRB 260910B: Fermi GBM Final Real-time Localization
  21. GRB 260909A: KAIT optical upper limit
  22. GRB 260903A: Swift-XRT observations
  23. EP260806a: VLA+ALMA radio detections
  24. GRB 260909A: OHP/T193 z-band upper limit
  25. GRB 260909A: VLT optical and near-infrared upper limits
  26. GRB 260909A: EP-FXT follow-up observation
  27. GRB 260910A: Fermi GBM Final Real-time Localization
  28. EP260806a: NOEMA detection
  29. EP260623a: NOEMA detections
  30. GRB 260909A: SVOM/VT optical upper limits
  31. GRB 260909A: SVOM/GRM observation
  32. GRB 260909A: Mondy optical observations and afterglow candidate
  33. GRB 260909A: Xinglong 2.16m optical upper limit
  34. GRB 260909A: SVOM/C-GFT optical upper limit
  35. GRB 260909A: SVOM detection of a burst
  36. The EP-WXT trigger 01709306297 is likely the known LMXB 4U 1745-203
  37. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  38. GRB 260903A: Swift ToO observations
  39. GRB 260903A: SAO RAS optical upper limit
  40. The EP-WXT trigger 01709305715 is likely a flaring star
  41. GRB 260907B: Fermi GBM Final Real-time Localization
  42. GRB 260907A: Fermi GBM Final Real-time Localization
  43. EP260903a: EP-FXT follow-up observation
  44. The EP-WXT trigger 01709302592 is likely a flaring star
  45. GRB 260903A: J-band upper limit with WINTER
  46. GRB 260903A: SVOM/ECLAIRs refined analysis
  47. GRB260903A: Liverpool Telescope optical observations
  48. GRB 260903A: SAO RAS optical observations
  49. GRB 260830A: GECAM-B detection of a burst
  50. EP260903a: EP-WXT detection of a fast X-ray transient
  51. GRB 260830A: Insight-HXMT/HE detection
  52. GRB 260903A: EP-FXT follow-up observation
  53. GRB 260903A: OHP/T193 optical afterglow detection
  54. GRB 260903A: NOT optical observations and afterglow fading
  55. NuSTAR Transient 260828: SOAR Optical Upper Limits
  56. SVOM GRB260903A: Global MASTER-Net observations report
  57. GRB 260903A: LCO optical observations
  58. GRB 260903A: SVOM/VT optical candidate
  59. GRB 260903A: Retraction of optical counterpart of GCN 45501
  60. GRB 260831A: GECAM-B observation
  61. GRB 260903A: LCO optical counterpart detection
  62. GRB 260827A: Insight-HXMT/HE detection
  63. GRB 260903A: SVOM detection of a soft faint burst
  64. EP260901a: SVOM/VT optical upper limits
  65. EP260901a: EP-FXT follow-up observation
  66. Konus-Wind detection of GRB 260829A
  67. GRB 260829A: SVOM/GRM observation
  68. GRB 260818A: ATCA detection of a candidate radio counterpart
  69. EP260830a: EP-FXT follow-up observation
  70. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  71. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  72. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  73. NuSTAR Transient 260828: LCO Optical Upper Limits
  74. EP260901a: EP-WXT detection of a fast X-ray transient
  75. SVOM trigger sb26083106 is not a GRB
  76. GRB 260829A: AstroSat CZTI detection
  77. GRB 260831B: EP-FXT follow-up observation
  78. GRB 260830A: NuSTAR detection of prompt emission
  79. GRB 260831B: LCO optical upper limits
  80. EP260830a: EP-WXT detection of a fast X-ray transient
  81. GRB 260827A: SVOM/GRM observation
  82. NuSTAR 260828: a 1100s hard X-ray transient
  83. GRB 260831B: SVOM detection of a possible burst
  84. IPN triangulation of GRB 260829A
  85. GRB 260827A: Glowbug gamma-ray detection
  86. EP260727a: ATCA 10 GHz detection
  87. GRB 260831A: Fermi GBM Final Real-time Localization
  88. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  89. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  90. GRB 260829A: GECAM-B observation of a long burst
  91. GRB 260825A: SVOM/GRM observation of a long burst
  92. GRB 260825A: GECAM-B observation
  93. GRB 260829A: Fermi GBM Detection
  94. GRB 260825A: AstroSat CZTI detection
  95. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  96. GRB 260829A: Fermi GBM Final Real-time Localization
  97. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  98. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  99. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  100. Fermi GBM trigger 809666623/260829141 is not a GRB

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