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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"

27636 results found.

  1. EP260306a: SVOM/VT optical observation
  2. EP260302a: Gemini-South redshift z = 1.535
  3. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  4. The EP-WXT trigger 01709258759: Las Cumbres discovery of the optical counterpart
  5. EP260302a: Optical afterglow rebrightening
  6. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  7. GRB 260303A: 1.3m DFOT optical upper limit
  8. EP260214b: ATCA 6 GHz observations
  9. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  10. GRB 260303A: SVOM/ECLAIRs refined analysis
  11. Fermi GRB 260305A: Global MASTER-Net observations report
  12. GRB 260305A: Fermi GBM Final Real-time Localization
  13. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  14. GRB 260303A: SVOM/VT optical observations
  15. GRB 260303A: J-band observations with WINTER
  16. EP260302a: Global MASTER-Net observations report
  17. Fermi GRB 260303B: Global MASTER-Net observations report
  18. GRB 260225A: SVOM/ECLAIRs refined analysis
  19. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  20. GRB 260303B: Fermi GBM Final Real-time Localization
  21. EP260302a: analysis of the follow-up EP-FXT observation
  22. EP260302a: LCO observations
  23. EP260302a: BOOTES-7 optical counterpart detection at early times
  24. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  25. GRB 260303A: SVOM detection of a burst
  26. GRB 260228A: EP-FXT follow-up observation
  27. The EP-WXT trigger 01709258736: Las Cumbres discovery of the optical counterpart
  28. GRB 260302A: Fermi GBM Final Real-time Localization
  29. GRB 260228A: CAHA 2.2m telescope optical upper limit
  30. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  31. EP260227a: Mephisto optical detection
  32. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  33. EP260227a: SVOM/VT optical observation
  34. GRB 260228A: SVOM/VT optical upper limits
  35. GRB 260225D: SVOM/GRM observation
  36. EP260227A: 3.6m DOT optical afterglow detection
  37. GRB 260225B: SVOM/GRM observation
  38. GRB 260228A: SVOM detection of a burst
  39. EP260227a: FTW optical and NIR observations
  40. EP260227a: Liverpool Telescope optical observations
  41. EP260227a: LCOGT Optical Observations
  42. GRB 260226A: Asiago r-band upper limit
  43. EP260227a: Thai National Telescope observations
  44. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  45. EP260227a: COLIBRÍ optical observations
  46. EP260227a: NOT optical observations
  47. EP260227a: Global MASTER-Net observations report
  48. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  49. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  50. EP260214a: VLT/FORS2 optical observations
  51. GRB 260225A: WINTER J-band upper limit
  52. GRB 260226A: COLIBRÍ optical upper limits
  53. GRB 260226A: LCOGT Optical Upper Limit
  54. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  55. GRB 260226A: Glowbug gamma-ray detection
  56. GRB 260226A : GROWTH-India Telescope optical observations
  57. GRB 260226A: Fermi GBM observation
  58. GRB 260226A: Fermi-LAT refined analysis
  59. The EP-WXT trigger 01709258652 is likely a flaring star
  60. LAT GRB260226.44: Global MASTER-Net observations report
  61. Fermi GRB 260226A: Global MASTER-Net observations report
  62. GRB 260226A: AstroSat CZTI detection of bright long burst
  63. EP260214a: VLA 6 GHz detection
  64. GRB 260226A: Fermi-LAT detection of a bright burst
  65. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  66. EP260224a: LCO optical upper limits
  67. GRB 260226A: Fermi GBM Final Real-time Localization
  68. GRB 260225A: EP-FXT follow-up observation
  69. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  70. GRB 260225C: Fermi GBM Final Real-time Localization
  71. GRB 260223A: Fermi GBM Observation
  72. GRB 260225A: SVOM/VT optical upper limits
  73. GRB 260225B: Fermi GBM Final Real-time Localization
  74. EP260126a: VLA 6 GHz detection
  75. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  76. GRB 260225A: SVOM detection of a burst
  77. EP260224a: Einstein Probe detection of an X-ray transient
  78. EP 260225.148: COLIBRÍ Confirmation of flaring star
  79. EP260223a: Xinglong optical upper limit
  80. The EP-WXT trigger 01709258631 is likely a flaring star
  81. EP260213a: Mephisto optical upper limits
  82. sb26021801: SVOM/VT optical upper limits
  83. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  84. sb26021801: SVOM/C-GFT upper limit
  85. EP260223a: COLIBRÍ optical upper limits
  86. EP260223a: Einstein Probe detection of an X-ray transient
  87. GRB 260223A: SVOM/VT optical observation
  88. GRB 260223A: SVOM/GRM observation
  89. GRB 260223A: COLIBRÍ further optical observations and a brightening
  90. EP260221a: Optical upper limit with Kinder observations
  91. GRB 260223A: COLIBRÍ optical observations
  92. GRB 260223A: DDOTI Optical Candidate
  93. GRB 260223A: BALROG localization (Fermi Trigger 793512674 / GRB 260223174)
  94. Fermi GRB 260223A: Global MASTER-Net observations report
  95. GRB 260223A: Fermi GBM Final Real-time Localization
  96. EP260221a: COLIBRÍ optical counterpart candidate
  97. EP260221a: Gemini South z-band upper limit
  98. GRB 260222A: Fermi GBM Final Real-time Localization
  99. EP260221a: Global MASTER-Net observations report
  100. Fermi GRB 260221B: Global MASTER-Net observations report

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