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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

32544 results found.

  1. GRB 260710A: AstroSat CZTI detection
  2. GRB 260709A: AstroSat CZTI detection
  3. GRB 260714B: AstroSat CZTI detection
  4. GRB 260714B: Fermi-LAT detection
  5. IceCube-260712A: Upper limits from a search for additional neutrino events in IceCube
  6. IceCube-260712A: LAST optical follow-up observations of the IceCube neutrino candidate
  7. GRB 260706A: ATCA detection of possible radio counterpart
  8. GRB 260705A: ATCA radio observations
  9. GRB 260619A: SVOM/VT continuous optical observations
  10. GRB 260618B: SVOM/VT optical observations indicate shallow decay and reddening
  11. GRB 260708A: slowly decaying X-ray emission observed by EP/FXT
  12. EP260623a: KAIT optical observations
  13. EP260711a: EP-FXT follow-up observation
  14. GRB 260708A: GRANDMA Optical Observations
  15. Fermi-LAT Gamma-ray Observations of IceCube-260712A
  16. Fermi-LAT Gamma-ray Observations of IceCube-260708A
  17. GRB 260710A: Insight-HXMT/HE detection
  18. Fermi-LAT Gamma-ray Observations of IceCube-260704A
  19. IceCube-260708A: Upper limits from a search for additional neutrino events in IceCube
  20. IceCube-260712A - IceCube observation of a high-energy neutrino candidate track-like event
  21. GRB 260708A: LCO optical observations
  22. GRB 260710A: Fermi GBM Detection
  23. GRB 260709A: SVOM/GRM detection
  24. GRB 260709A: GECAM-B observation
  25. IceCube-260708A: Observations with the Vera C. Rubin Observatory
  26. EP-WXT trigger 0170924151 : RAPAS optical counterpart candidate detection
  27. GRB 260705C: AstroSat CZTI detection
  28. GRB 260708A: Glowbug gamma-ray detection
  29. GRB 260704A: SVOM/ECLAIRs refined analysis
  30. GRB 260706A : GRANDMA Upper limits
  31. GRB 260708A: Kilonova-Catcher optical afterglow detection
  32. GRB 260708A: GECAM-B observation of a burst
  33. IceCube-260708A: One candidate from the Zwicky Transient Facility
  34. GRB 260708A: Fermi-GBM observation
  35. Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
  36. IceCube-260708A - IceCube observation of a high-energy neutrino candidate track-like event
  37. GRB 260708A: Fermi-LAT detection
  38. GRB 260705B: SVOM/GRM observation
  39. GRB 260706A: Further EP-FXT follow-up observation
  40. GRB 260706A: SVOM/VT optical upper limits
  41. EP260707a (by EP-FXT): NOT optical upper limit
  42. EP260707a is not a real source
  43. EP260707a: LCOGT Optical Upper Limit
  44. EP260707a: TRT optical upper limit
  45. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  46. GRB 260705C: Glowbug gamma-ray detection of a short burst
  47. GRB 260706A: SVOM/ECLAIRs refined analysis
  48. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  49. GRB 260706A: SVOM/GRM observation
  50. GRB 260706A: REM optical/NIR observations
  51. IceCube-260704A: No candidates from the Zwicky Transient Facility
  52. GRB 260706A: LCO optical upper limit
  53. GRB 260706A: EP-FXT follow-up observation
  54. GRB 260706A: Fermi GBM Observation
  55. IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
  56. IPN triangulation of GRB 260627A
  57. GRB 260705A: SVOM/ECLAIRs refined analysis
  58. GRB 260706A: SVOM detection of a burst
  59. The EP-WXT trigger 01709274014: KAIT confirmation of a stellar flare
  60. IceCube260704A: OHP/T193 optical observations
  61. GRB 260705A: LCO optical upper limits
  62. GRB 260704A: NOT optical upper limits
  63. Fermi GBM Sub-Threshold Detection of GRB 260705A
  64. GRB 260704A: EP-FXT follow-up observation
  65. GRB 260629A: SVOM/GRM observation of a short burst
  66. GRB 260629A: GECAM-A observation of a short burst
  67. IceCube-260704A - IceCube observation of a high-energy neutrino candidate track-like event
  68. GRB 260629A: AstroSat CZTI detection
  69. EP260703a: EP-FXT follow-up observation
  70. Fermi GRB 260703A: Global MASTER-Net observations report
  71. GRB 260610B: VLA detection
  72. GRB 260623A: Glowbug gamma-ray detection
  73. GRB 260614B: ATCA Radio Upper Limits
  74. GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve
  75. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  76. EP260628a: EP-FXT follow-up observation
  77. Fermi GRB 260628A: Global MASTER-Net observations report
  78. EP260626a: further Liverpool Telescope optical upper limits
  79. EP260626a: EP-FXT follow-up observation
  80. EP260626a: COLIBRÍ optical upper limit
  81. EP260626a: Liverpool Telescope upper limits
  82. Konus-Wind detection of GRB 260623B / EP260623a
  83. EP260623a: TNG NIR afterglow detection
  84. GRB 260618A: Fermi GBM Observation
  85. MASS-Cube (GRID 2.0) detection of GRB 260616B
  86. EP260623a: FTW optical and NIR observations
  87. GRB 260619A: SVOM/ECLAIRs refined analysis
  88. EP260623a: Liverpool Telescope optical observations
  89. Konus-Wind detection of GRB 260618B
  90. GRB 260624A: Fermi GBM Final Real-time Localization (Duplicate Submission)
  91. EP260623a:refined analysis of the EP-WXT and EP-FXT observation
  92. EP260623a: WINTER J-band observations
  93. GRB 260617A: Glowbug gamma-ray detection of a short burst
  94. IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
  95. IPN triangulation of GRB 260605A
  96. EP260623a: Optical follow-up observations with Kinder
  97. EP260623a: FRAM-ORM detection of the optical afterglow rise, peak and decay
  98. EP260623a: SVOM/VT optical observations
  99. EP260623a: TRT optical observations
  100. EP260623a: REM optical/NIR afterglow detection

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