Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

45487 results found.

  1. GRB 260515A: OHP/T193 optical observations
  2. EP260514a: COLIBRÍ optical upper limits
  3. GRB 260516A: Fermi GBM Final Real-time Localization
  4. GRID detection of GRB 260507A
  5. GRB 260515A: GTC/OSIRIS+ spectroscopic redshift z = 0.764
  6. GRB 260515A: LCO optical observations
  7. SVOM GRB 260515A: Global MASTER-Net observations report
  8. GRB 260515A: NOT optical observations.
  9. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  10. GRB 260515A: SVOM/VT optical candidate from VHF data
  11. GRB 260515A: JinShan optical counterpart candidate
  12. GRB 260515A: SVOM detection of a burst
  13. GRB 260510C: Glowbug gamma-ray detection
  14. IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility
  15. EP260514a: GROWTH-India Telescope optical upper limit
  16. GRB 260511B: NOT optical observations
  17. Konus-Wind detection of GRB 260512A
  18. GRB 260510C: CALET Gamma-Ray Burst Monitor detection
  19. GRB 260511B: GMG Optical Upper Limit
  20. EP260514a: Global MASTER-Net observations report
  21. EP260514a: Einstein Probe detection of a fast X-ray transient
  22. EP260512a: LCO optical upper limits
  23. IPN triangulation of GRB 260512A
  24. GRB 260511B: Mephisto multi-band optical followup
  25. Fermi GRB 260514A: Global MASTER-Net observations report
  26. GRB 260512A: AstroSat CZTI detection
  27. The EP-WXT trigger 01709262077 is likely a flaring star
  28. EP260512a: EP-FXT follow-up observation
  29. EP260507a: Xinglong Schmidt optical counterpart detection
  30. GRB 260514A: Fermi GBM Final Real-time Localization
  31. EP260512a: Global MASTER-Net observations report
  32. Fermi GRB 260513A: Global MASTER-Net observations report
  33. Fermi GRB 260512A: Global MASTER-Net observations report
  34. GRB 260511B: further SAO RAS optical observations
  35. GRB 260513A: Fermi GBM Final Real-time Localization
  36. GRB 260509A: SVOM/VT optical observations
  37. Konus-Wind detection of GRB 260511B
  38. The EP-WXT trigger 01709262036 is likely a flaring star
  39. EP260512a: COLIBRÍ optical upper limits
  40. EP260512a: Einstein Probe detection of an X-ray transient
  41. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  42. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  43. GRB 260512A: NuSTAR detection of prompt emission
  44. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  45. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  46. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  47. GRB 260512A: Fermi GBM Final Real-time Localization
  48. GRB 260511A: Glowbug gamma-ray detection
  49. Konus-Wind detection of GRB 260511A
  50. MASS-Cube (GRID 2.0) detection of GRB 260511A
  51. MASS-Cube (GRID 2.0) detection of GRB 260507A
  52. GRB 260511B: SAO RAS optical observations
  53. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  54. GRB 260511B: FRAM-ORM optical detection
  55. GRB 260511A: EP-FXT follow-up observation
  56. GRB 260511B: EP-FXT follow-up observation
  57. GRB 260511B: LCO optical counterpart detection
  58. GRB260511B: MAO/AZT-22 optical observations
  59. GRB 260511A: SVOM/VT optical observations
  60. GRB 260511B: LCO optical observations
  61. GRB 260511B: OHP/T193 spectroscopic observations
  62. GRB 260511B: GOTO optical counterpart detection
  63. GRB 260511B: Xinglong 2.16m/BEFOSC redshift confirmation
  64. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  65. GRB 260511B: SVOM/VT optical observations
  66. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  67. GRB 260510B: EP-FXT follow-up observation
  68. GRB 260511B: OSIRIS+/GTC redshift z=2.006
  69. GRB 260510C: Fermi GBM Observation
  70. GRB 260509A: SAO RAS optical observations
  71. GRB 260511A: REM near-infrared detection
  72. GRB 260511B: GROWTH-India Telescope optical observations
  73. GRB 260511B: AstroSat CZTI detection
  74. GRB 260506B: Glowbug gamma-ray detection
  75. GRB 260506A: Glowbug gamma-ray detection of a short burst
  76. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  77. GRB 260511B: NuSTAR detection of prompt emission
  78. GRB 260511A: NuSTAR detection of prompt emission
  79. GRB 260511B: Fermi GBM Detection
  80. GRB 260511C: Fermi GBM Final Real-time Localization
  81. GRB 260511B: SVOM/VT optical observation with VHF data
  82. GRB 260511B: TRT optical observation
  83. GRB 260510B: SVOM/ECLAIRs refined analysis
  84. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  85. GRB 260511A: Fermi GBM Detection
  86. GRB 260511B SVOM/C-GFT optical counterpart detection
  87. EP260509a: LCO optical upper limits
  88. GRB 260511A: UTGO H50 optical afterglow observation
  89. GRB 260510C: AstroSat CZTI detection
  90. GRB 260511B: SVOM detection of a burst
  91. GRB 260511B: Fermi GBM Final Real-time Localization
  92. GRB 260510C: EP-FXT follow-up observation
  93. GRB 260510C: SVOM/VT optical counterpart confirmation
  94. EP260509a: EP-FXT non-detection and upper limit
  95. GRB 260511A: SVOM/VT optical observation with VHF data
  96. Fermi GRB 260511A: Global MASTER-Net observations report
  97. GRB 260511A: KAIT optical afterglow observations
  98. GRB 260511A: LCO optical afterglow detection
  99. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  100. GRB 260511A: TRT optical counterpart detection

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov