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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"

32549 results found.

  1. GRB 260225A: SVOM/VT optical continued observations and upper limit
  2. GRID detection of GRB 260223A
  3. EP260227a: Global MASTER-Net observations report
  4. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  5. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  6. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  7. Konus-Wind detection of GRB 260226A
  8. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  9. EP260214a: VLT/FORS2 optical observations
  10. GRB 260225A: WINTER J-band upper limit
  11. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  12. GRB 260226A: COLIBRÍ optical upper limits
  13. GRB 260226A: LCOGT Optical Upper Limit
  14. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  15. GRB 260226A: Glowbug gamma-ray detection
  16. GRB 260226A: NuSTAR detection of bright prompt emission
  17. GRB 260226A : GROWTH-India Telescope optical observations
  18. GRB 260226A: LAST optical upper limit
  19. GRB 260226A: Fermi GBM observation
  20. GRB 260226A: Fermi-LAT refined analysis
  21. Fermi GRB 260226A: Global MASTER-Net observations report
  22. GRB 260226A: AstroSat CZTI detection of bright long burst
  23. EP260214a: VLA 6 GHz detection
  24. GRB 260226A: Fermi-LAT detection of a bright burst
  25. EP260224a: LCO optical upper limits
  26. GRB260225A: SVOM/ECLAIRs refined position
  27. GRB 260225A: EP-FXT follow-up observation
  28. GRB 260225A: SVOM/VT optical observation
  29. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  30. GRB 260223A: Fermi GBM Observation
  31. GRB 260225A: SVOM/VT optical upper limits
  32. EP260126a: VLA 6 GHz detection
  33. EP260223a: Liverpool Telescope upper limits
  34. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  35. EP 260225.148: COLIBRÍ Confirmation of flaring star
  36. EP260223a: Xinglong optical upper limit
  37. GRB 260223A: Glowbug gamma-ray detection
  38. EP260213a: Mephisto optical upper limits
  39. EP260223a: EP-FXT follow-up observation
  40. sb26021801: SVOM/VT optical upper limits
  41. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  42. sb26021801: SVOM/C-GFT upper limit
  43. EP260223a: COLIBRÍ optical upper limits
  44. GRB 260223A: SVOM/VT optical observation
  45. GRB 260223A: SVOM/GRM observation
  46. GRB 260223A: COLIBRÍ further optical observations and a brightening
  47. EP260221a: Optical upper limit with Kinder observations
  48. GRB 260223A: COLIBRÍ optical observations
  49. GRB 260223A: DDOTI Optical Candidate
  50. Fermi GRB 260223A: Global MASTER-Net observations report
  51. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  52. EP260221a: COLIBRÍ optical counterpart candidate
  53. EP260221a: Gemini South z-band upper limit
  54. EP260221a: Global MASTER-Net observations report
  55. EP260221a: EP-FXT follow-up observation
  56. Fermi GRB 260221B: Global MASTER-Net observations report
  57. EP260221a: Xinglong optical upper limit
  58. Fermi GRB 260221A: Global MASTER-Net observations report
  59. EP260221a: GOTO optical upper limit
  60. EP260221a: COLIBRÍ optical upper limit
  61. SVOM alert sb26021801: LCO optical upper limit
  62. GRB 260219A: AstroSat CZTI detection
  63. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  64. GRB 260219A: GECAM-B observation of a long burst
  65. Fermi GRB 260219A: Global MASTER-Net observations report
  66. SVOM alert sb26021801: LAST optical upper limit
  67. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  68. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  69. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  70. EP260214b: Mondy optical observations
  71. EP260214b: 1.3m DFOT optical upper limit
  72. EP260210a: Mondy optical upper limits
  73. Konus-Wind detection of GRB 260212A
  74. GRB 260208A: AbAO and Terskol optical upper limits
  75. GRB 260208A: continued Mondy optical observations
  76. IPN triangulation of GRB 260212A
  77. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  78. GRB 260213A: GECAM-B observation of a short burst
  79. EP260214b: Liverpool Telescope optical observations
  80. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  81. EP260214b: Optical upper limit with Kinder observations
  82. EP260214a: Optical upper limits with Kinder observations
  83. EP260214b: EP-FXT follow-up observation
  84. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  85. EP260214b: DDOTI Optical Detection
  86. EP260214b: GROWTH-India Telescope optical upper limit
  87. EP260214a: VLT near-infrared observation
  88. EP260214b: SVOM/VT optical observation
  89. EP260214a: NOT optical upper limits
  90. EP260214a: COLIBRÍ optical upper limits
  91. EP260214b: OHP/T120 optical observations
  92. EP260214a: refined analysis of the EP-FXT observation
  93. EP260214b: LCO optical counterpart detection
  94. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  95. GRB 260211A: SVOM/VT optical counterpart
  96. EP260214b: COLIBRÍ optical observations
  97. EP260214a: SVOM/VT optical upper limits
  98. EP260214b: NOT optical counterpart detection
  99. EP260214a: Global MASTER-Net observations report
  100. GRB 260212A: AstroSat CZTI detection

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