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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"

27630 results found.

  1. GRB 260303A: 1.3m DFOT optical upper limit
  2. EP260214b: ATCA 6 GHz observations
  3. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  4. GRB 260303A: SVOM/ECLAIRs refined analysis
  5. Fermi GRB 260305A: Global MASTER-Net observations report
  6. GRB 260305A: Fermi GBM Final Real-time Localization
  7. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  8. GRB 260303A: SVOM/VT optical observations
  9. GRB 260303A: J-band observations with WINTER
  10. EP260302a: Global MASTER-Net observations report
  11. Fermi GRB 260303B: Global MASTER-Net observations report
  12. GRB 260225A: SVOM/ECLAIRs refined analysis
  13. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  14. GRB 260303B: Fermi GBM Final Real-time Localization
  15. EP260302a: analysis of the follow-up EP-FXT observation
  16. EP260302a: LCO observations
  17. EP260302a: BOOTES-7 optical counterpart detection at early times
  18. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  19. GRB 260303A: SVOM detection of a burst
  20. GRB 260228A: EP-FXT follow-up observation
  21. The EP-WXT trigger 01709258736: Las Cumbres discovery of the optical counterpart
  22. GRB 260302A: Fermi GBM Final Real-time Localization
  23. GRB 260228A: CAHA 2.2m telescope optical upper limit
  24. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  25. EP260227a: Mephisto optical detection
  26. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  27. EP260227a: SVOM/VT optical observation
  28. GRB 260228A: SVOM/VT optical upper limits
  29. GRB 260225D: SVOM/GRM observation
  30. EP260227A: 3.6m DOT optical afterglow detection
  31. GRB 260225B: SVOM/GRM observation
  32. GRB 260228A: SVOM detection of a burst
  33. EP260227a: FTW optical and NIR observations
  34. EP260227a: Liverpool Telescope optical observations
  35. EP260227a: LCOGT Optical Observations
  36. GRB 260226A: Asiago r-band upper limit
  37. EP260227a: Thai National Telescope observations
  38. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  39. EP260227a: COLIBRÍ optical observations
  40. EP260227a: NOT optical observations
  41. EP260227a: Global MASTER-Net observations report
  42. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  43. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  44. EP260214a: VLT/FORS2 optical observations
  45. GRB 260225A: WINTER J-band upper limit
  46. GRB 260226A: COLIBRÍ optical upper limits
  47. GRB 260226A: LCOGT Optical Upper Limit
  48. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  49. GRB 260226A: Glowbug gamma-ray detection
  50. GRB 260226A : GROWTH-India Telescope optical observations
  51. GRB 260226A: Fermi GBM observation
  52. GRB 260226A: Fermi-LAT refined analysis
  53. The EP-WXT trigger 01709258652 is likely a flaring star
  54. LAT GRB260226.44: Global MASTER-Net observations report
  55. Fermi GRB 260226A: Global MASTER-Net observations report
  56. GRB 260226A: AstroSat CZTI detection of bright long burst
  57. EP260214a: VLA 6 GHz detection
  58. GRB 260226A: Fermi-LAT detection of a bright burst
  59. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  60. EP260224a: LCO optical upper limits
  61. GRB 260226A: Fermi GBM Final Real-time Localization
  62. GRB 260225A: EP-FXT follow-up observation
  63. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  64. GRB 260225C: Fermi GBM Final Real-time Localization
  65. GRB 260223A: Fermi GBM Observation
  66. GRB 260225A: SVOM/VT optical upper limits
  67. GRB 260225B: Fermi GBM Final Real-time Localization
  68. EP260126a: VLA 6 GHz detection
  69. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  70. GRB 260225A: SVOM detection of a burst
  71. EP260224a: Einstein Probe detection of an X-ray transient
  72. EP 260225.148: COLIBRÍ Confirmation of flaring star
  73. EP260223a: Xinglong optical upper limit
  74. The EP-WXT trigger 01709258631 is likely a flaring star
  75. EP260213a: Mephisto optical upper limits
  76. sb26021801: SVOM/VT optical upper limits
  77. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  78. sb26021801: SVOM/C-GFT upper limit
  79. EP260223a: COLIBRÍ optical upper limits
  80. EP260223a: Einstein Probe detection of an X-ray transient
  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. GRB 260223A: BALROG localization (Fermi Trigger 793512674 / GRB 260223174)
  88. Fermi GRB 260223A: Global MASTER-Net observations report
  89. GRB 260223A: Fermi GBM Final Real-time Localization
  90. EP260221a: COLIBRÍ optical counterpart candidate
  91. EP260221a: Gemini South z-band upper limit
  92. GRB 260222A: Fermi GBM Final Real-time Localization
  93. EP260221a: Global MASTER-Net observations report
  94. Fermi GRB 260221B: Global MASTER-Net observations report
  95. GRB 260221B: Fermi GBM Final Real-time Localization
  96. EP-WXT01709258519: Xinglong optical upper limit
  97. EP260221a: Xinglong optical upper limit
  98. Fermi GRB 260221A: Global MASTER-Net observations report
  99. GRB 260221A: Fermi GBM Final Real-time Localization
  100. EP260221a: GOTO optical upper limit

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