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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"

32579 results found.

  1. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  2. GRB 260228A: SVOM/ECLAIRs refined analysis
  3. GRB 260225A: SVOM/ECLAIRs refined analysis
  4. EP260302a: analysis of the follow-up EP-FXT observation
  5. EP260227a: Gemini-South optical observations
  6. EP260302a: LCO observations
  7. EP260302a: BOOTES-7 optical counterpart detection at early times
  8. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  9. GRB 260228A: EP-FXT follow-up observation
  10. GRB 251130B: TERI Gamma-ray detection
  11. GRB 260208A: TERI Gamma-ray detection
  12. EP260227a: Mondy optical observations
  13. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  14. EP260227a: Mephisto optical detection
  15. GRID detection of GRB 260225D
  16. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  17. EP260227a: further LCO observations
  18. EP260227a: SVOM/VT optical observation
  19. GRB 260228A: SVOM/VT optical upper limits
  20. GRB 260225D: SVOM/GRM observation
  21. EP260227A: 3.6m DOT optical afterglow detection
  22. GRB 260225B: SVOM/GRM observation
  23. EP260227a: FTW optical and NIR observations
  24. EP260227a: Liverpool Telescope optical observations
  25. EP260227a: LCOGT Optical Observations
  26. GRB 260226A: Asiago r-band upper limit
  27. EP260227a: Thai National Telescope observations
  28. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  29. EP260227a: Liverpool Telescope observations
  30. EP260227a: COLIBRÍ optical observations
  31. EP260227a: NOT optical observations
  32. GRB 260225A: SVOM/VT optical continued observations and upper limit
  33. GRID detection of GRB 260223A
  34. EP260227a: Global MASTER-Net observations report
  35. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  36. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  37. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  38. Konus-Wind detection of GRB 260226A
  39. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  40. EP260214a: VLT/FORS2 optical observations
  41. GRB 260225A: WINTER J-band upper limit
  42. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  43. GRB 260226A: COLIBRÍ optical upper limits
  44. GRB 260226A: LCOGT Optical Upper Limit
  45. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  46. GRB 260226A: Glowbug gamma-ray detection
  47. GRB 260226A: NuSTAR detection of bright prompt emission
  48. GRB 260226A : GROWTH-India Telescope optical observations
  49. GRB 260226A: LAST optical upper limit
  50. GRB 260226A: Fermi GBM observation
  51. GRB 260226A: Fermi-LAT refined analysis
  52. Fermi GRB 260226A: Global MASTER-Net observations report
  53. GRB 260226A: AstroSat CZTI detection of bright long burst
  54. EP260214a: VLA 6 GHz detection
  55. GRB 260226A: Fermi-LAT detection of a bright burst
  56. EP260224a: LCO optical upper limits
  57. GRB260225A: SVOM/ECLAIRs refined position
  58. GRB 260225A: EP-FXT follow-up observation
  59. GRB 260225A: SVOM/VT optical observation
  60. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  61. GRB 260223A: Fermi GBM Observation
  62. GRB 260225A: SVOM/VT optical upper limits
  63. EP260126a: VLA 6 GHz detection
  64. EP260223a: Liverpool Telescope upper limits
  65. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  66. EP 260225.148: COLIBRÍ Confirmation of flaring star
  67. EP260223a: Xinglong optical upper limit
  68. GRB 260223A: Glowbug gamma-ray detection
  69. EP260213a: Mephisto optical upper limits
  70. EP260223a: EP-FXT follow-up observation
  71. sb26021801: SVOM/VT optical upper limits
  72. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  73. sb26021801: SVOM/C-GFT upper limit
  74. EP260223a: COLIBRÍ optical upper limits
  75. GRB 260223A: SVOM/VT optical observation
  76. GRB 260223A: SVOM/GRM observation
  77. GRB 260223A: COLIBRÍ further optical observations and a brightening
  78. EP260221a: Optical upper limit with Kinder observations
  79. GRB 260223A: COLIBRÍ optical observations
  80. GRB 260223A: DDOTI Optical Candidate
  81. Fermi GRB 260223A: Global MASTER-Net observations report
  82. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  83. EP260221a: COLIBRÍ optical counterpart candidate
  84. EP260221a: Gemini South z-band upper limit
  85. EP260221a: Global MASTER-Net observations report
  86. EP260221a: EP-FXT follow-up observation
  87. Fermi GRB 260221B: Global MASTER-Net observations report
  88. EP260221a: Xinglong optical upper limit
  89. Fermi GRB 260221A: Global MASTER-Net observations report
  90. EP260221a: GOTO optical upper limit
  91. EP260221a: COLIBRÍ optical upper limit
  92. SVOM alert sb26021801: LCO optical upper limit
  93. GRB 260219A: AstroSat CZTI detection
  94. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  95. GRB 260219A: GECAM-B observation of a long burst
  96. Fermi GRB 260219A: Global MASTER-Net observations report
  97. SVOM alert sb26021801: LAST optical upper limit
  98. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  99. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  100. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search

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