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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"

32685 results found.

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

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