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"

32493 results found.

  1. GRB 260522A: Fermi-LAT detection
  2. GRB 260519C: SVOM/GRM observation
  3. GRB 260511A: iTelescope T-75 optical detection
  4. GRB 260520B: SVOM/GRM observation
  5. GRB 260411B: TERI Gamma-ray detection
  6. GRB 260407A: TERI Gamma-ray detection
  7. GRB 260307A: TERI Gamma-ray detection
  8. GRB 260225D: TERI Gamma-ray detection
  9. GRB 251118A: TERI Gamma-ray detection
  10. GRB 251113A: TERI Gamma-ray detection
  11. GRB 260428A: TERI Gamma-ray detection
  12. Konus-Wind detection of GRB 260519C
  13. GRB 260509A: SVOM/ECLAIRs refined analysis
  14. GRB 260519C: NuSTAR detection of prompt emission
  15. Konus-Wind detection of GRB 260518A
  16. GRB 260516D: SVOM/ECLAIRs refined analysis
  17. GRB 260515A: SVOM/ECLAIRs refined analysis
  18. GRB 260421B: radio detection with the VLA
  19. GRID detection of GRB 260511A
  20. GRB 260509A: CrAO ZTSh optical upper limit (Duplicate Submission)
  21. GRB 260509A: CrAO ZTSh optical upper limit
  22. GRB 260516D: EP-FXT follow-up observation
  23. GRB 260516D: GOTO optical counterpart detection
  24. GRB 260516D: LCO optical observations
  25. GRB 260515A: further Liverpool Telescope observations
  26. GRB 260516D: SVOM/COLIBRÍ (FM-GFT) optical observations
  27. GRB 260516D: GTC/OSIRIS+ spectroscopic redshift z = 1.801
  28. GRB 260516D: GROWTH-India Telescope optical detection
  29. GRB 260516D: SVOM/VT optical bright candidate
  30. GRB 260515A: CrAO ZTSh BVRI optical observations
  31. Fermi GRB 260516C: Global MASTER-Net observations report
  32. Konus-Wind detection of GRB 260515A
  33. GRB 260515A: Liverpool Telescope optical detection
  34. GRB 260515A: LCO optical counterpart detection
  35. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) optical observations
  36. GRB 260515A: EP-FXT follow-up observation
  37. EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  38. EP260514a: NOT optical counterpart confirmation
  39. EP260514a: TRT optical counterpart candidate
  40. EP260514a: SVOM/VT optical candidate
  41. Fermi GRB 260516B: Global MASTER-Net observations report
  42. GRB 260515A: SVOM/VT optical observations
  43. GRB 260515A: OHP/T193 optical observations
  44. EP260514a: COLIBRÍ optical upper limits
  45. GRID detection of GRB 260507A
  46. GRB 260515A: GTC/OSIRIS+ spectroscopic redshift z = 0.764
  47. GRB 260515A: LCO optical observations
  48. SVOM GRB 260515A: Global MASTER-Net observations report
  49. GRB 260515A: NOT optical observations.
  50. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  51. GRB 260515A: SVOM/VT optical candidate from VHF data
  52. GRB 260515A: JinShan optical counterpart candidate
  53. GRB 260510C: Glowbug gamma-ray detection
  54. IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility
  55. EP260514a: GROWTH-India Telescope optical upper limit
  56. GRB 260511B: NOT optical observations
  57. Konus-Wind detection of GRB 260512A
  58. GRB 260510C: CALET Gamma-Ray Burst Monitor detection
  59. GRB 260511B: GMG Optical Upper Limit
  60. EP260514a: Global MASTER-Net observations report
  61. EP260512a: LCO optical upper limits
  62. IPN triangulation of GRB 260512A
  63. GRB 260511B: Mephisto multi-band optical followup
  64. Fermi GRB 260514A: Global MASTER-Net observations report
  65. GRB 260512A: AstroSat CZTI detection
  66. EP260512a: EP-FXT follow-up observation
  67. EP260507a: Xinglong Schmidt optical counterpart detection
  68. EP260512a: Global MASTER-Net observations report
  69. Fermi GRB 260513A: Global MASTER-Net observations report
  70. Fermi GRB 260512A: Global MASTER-Net observations report
  71. GRB 260511B: further SAO RAS optical observations
  72. GRB 260509A: SVOM/VT optical observations
  73. Konus-Wind detection of GRB 260511B
  74. EP260512a: COLIBRÍ optical upper limits
  75. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  76. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  77. GRB 260512A: NuSTAR detection of prompt emission
  78. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  79. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  80. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  81. GRB 260511A: Glowbug gamma-ray detection
  82. Konus-Wind detection of GRB 260511A
  83. MASS-Cube (GRID 2.0) detection of GRB 260511A
  84. MASS-Cube (GRID 2.0) detection of GRB 260507A
  85. GRB 260511B: SAO RAS optical observations
  86. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  87. GRB 260511B: FRAM-ORM optical detection
  88. GRB 260511A: EP-FXT follow-up observation
  89. GRB 260511B: EP-FXT follow-up observation
  90. GRB 260511B: LCO optical counterpart detection
  91. GRB260511B: MAO/AZT-22 optical observations
  92. GRB 260511A: SVOM/VT optical observations
  93. GRB 260511B: LCO optical observations
  94. GRB 260511B: OHP/T193 spectroscopic observations
  95. GRB 260511B: GOTO optical counterpart detection
  96. GRB 260511B: Xinglong 2.16m/BEFOSC redshift confirmation
  97. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  98. GRB 260511B: SVOM/VT optical observations
  99. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  100. GRB 260510B: EP-FXT follow-up observation

Advanced

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