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"

23256 results found.

  1. GRB 260825A: SVOM/GRM observation of a long burst
  2. GRB 260818B: Further EP-FXT observation
  3. GRB 260818B: VLT optical and nIR observations
  4. GRB 260818B: TNG NIR observations
  5. GRB 260818B: 6 GHz VLA observations
  6. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  7. GRB 260808B: SAO RAS observations of the optical rebrightening
  8. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  9. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  10. EP260822a: EP-FXT non-detection and upper limit
  11. GRB 260822A: GOTO optical counterpart detection
  12. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  13. EP260822a: Einstein Probe detection of a fast X-ray transient
  14. GRB 260822A: LCO optical upper limits
  15. GRB 260822A: GROWTH-India Telescope Upper Limits
  16. GRB 260818B: VLA radio observations
  17. GRB 260818B: SVOM/C-GFT optical upper limit
  18. EP detected a brightening of LMXB 1ES 1735-26.9
  19. GRB 260818A: J-band observations with WINTER
  20. GRB 260818B: NOT optical upper limits
  21. GRB 260810A: SVOM/GRM observation
  22. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  23. GRB 260818B: LCO optical upper limits
  24. EP260806a: SAO RAS multicolor optical observations
  25. GRB 260818A: LCO optical upper limits
  26. EP260812a: AbAO optical upper limit
  27. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  28. EP260806a: NUTTELA-TAO optical observations
  29. EP260812a: AZT-22 optical upper limit
  30. EP260806a: WFST optical observations
  31. EP260812b: Optical upper limit with Kinder
  32. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  33. GRB 260808B: Liverpool Telescope further optical observations
  34. GRB 260808B: GTC/OSIRIS+ spectroscopic redshift z = 1.295
  35. EP260812a: NOT and Liverpool Telescope upper limits:
  36. EP260812b: Liverpool Telescope observations
  37. EP260812b: GOTO detection of the optical counterpart
  38. EP260812a: refined analysis of the EP-WXT and autonomous EP-FXT observation
  39. EP260812a: SVOM/C-GFT optical upper limit
  40. EP260812b: COLIBRÍ optical observations
  41. EP260812b: SVOM/VT optical observation
  42. GRB 260808A: SVOM/GRM observation
  43. EP260812b: Einstein Probe detection of an X-ray transient
  44. EP trigger #01709278129 (EP260812b?): NOT optical counterpart
  45. GRB 260810A: Glowbug gamma-ray detection
  46. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  47. GRB 260810A: AstroSat CZTI detection of a long burst
  48. EP260812a: Einstein Probe detection of an X-ray transient
  49. GRB 260809A: SAO RAS optical observations
  50. GRB 260808B: SAO RAS optical observations
  51. GRB 260808B: SVOM/VT optical re-brightening at day 3
  52. EP260806a: MAO/AZT-22 optical observations
  53. GRB260808B: MAO/AZT-22 optical observations
  54. GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
  55. GRB 260809A: J-band upper limit with WINTER
  56. GRB 260806A: Glowbug gamma-ray detection
  57. GRB260809A/EPF_J234751.2+210212: EP-FXT follow-up observation
  58. GRB 260809A: SVOM/COLIBRÍ (FM-GFT) optical observation
  59. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
  60. GRB 260809A: NOT optical observations
  61. GRB260809A: MAO/AZT-22 optical observations
  62. GRB260809A: OHP/T193 optical observations
  63. EP260809a: J-band upper limit with WINTER
  64. GRB 260808B: J-band upper limit with WINTER
  65. EP260809a:refined analysis of the EP-WXT and autonomous EP-FXT observation
  66. GRB 260809A: SVOM detection of a faint burst
  67. GRB 260808B: Liverpool Telescope optical observations
  68. GRB 260808B: NOT optical observations
  69. GRB 260808B: LCO optical observations
  70. EP260809a: COLIBRÍ optical observations
  71. EP260809a: LCO optical observation
  72. EP260809a: OHP/T193 optical observations
  73. GRB260808B: OHP/T193 optical observations
  74. EP260809a: Einstein Probe detection of an X-ray transient
  75. GRB 260808B: SVOM/VT optical candidate from VHF data ( localization correction for GCN 45317 )
  76. GRB 260808B: SVOM/VT optical candidate from VHF data
  77. GRB 260808B: SVOM detection of a faint burst
  78. GRB 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  79. EP260806a: COLIBRÍ optical observations
  80. EP260806a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  81. EP260806a: SVOM/VT optical observation
  82. EP260806a: Liverpool Telescope observations of the counterpart show a blue colour
  83. EP260806a: OSIRIS+/GTC redshift z=0.089
  84. EP260731a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  85. EP260806a: LCO likely optical counterpart
  86. EP260806a: Einstein Probe detection of an X-ray transient
  87. GRB 260715A: cubesat Avion detection
  88. GRB 260709A: cubesat Avion detection
  89. GRB 260708A: cubesat Avion detection
  90. GRB 260730B: Glowbug gamma-ray detection
  91. GRB 260805C: Glowbug gamma-ray detection
  92. GRB 260805B: Glowbug gamma-ray detection
  93. GRB 260804A: Glowbug gamma-ray detection
  94. GRB 260803A: Fermi GBM Final Real-time Localization
  95. GRB 260802A / EP J223759.5+521421: EP-FXT follow-up observation
  96. GRB 260802A: SVOM/VT optical upper limits from VHF data
  97. GRB 260802A: LCO optical upper limits
  98. GRB 260802A / EP J223759.5+531421: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  99. GRB 260802A/EP J223759.5+531421: SVOM detection of a possible magnetar burst
  100. GRB 260731A: AstroSat CZTI detection of a long burst

Advanced

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