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"

20353 results found.

  1. GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  2. GRB 260914A: SVOM detection of a burst
  3. GRB 260913A: SVOM trigger sb26091302 is not an astrophysical event
  4. GRB 260913A: SVOM/C-GFT optical upper limit
  5. GRB 260913A: SVOM detection of a faint burst
  6. GRB 260909A: OSN 1.5m, CAHA 2.2m and GTC 10.4m optical upper limits
  7. GRB 260907A: SVOM/GRM observation
  8. GRB 260909A: CrAO and AbAO optical upper limits
  9. GRB 260909A: SVOM/ECLAIRs refined analysis
  10. GRB 260909A: KAIT optical upper limit
  11. GRB 260903A: Swift-XRT observations
  12. GRB 260909A: OHP/T193 z-band upper limit
  13. GRB 260909A: VLT optical and near-infrared upper limits
  14. EP260806a: NOEMA detection
  15. EP260623a: NOEMA detections
  16. GRB 260909A: Mondy optical observations and afterglow candidate
  17. GRB 260909A: Xinglong 2.16m optical upper limit
  18. GRB 260909A: SVOM/C-GFT optical upper limit
  19. GRB 260909A: SVOM detection of a burst
  20. GRB 260903A: SAO RAS optical upper limit
  21. GRB 260903A: J-band upper limit with WINTER
  22. GRB 260903A: SVOM/ECLAIRs refined analysis
  23. GRB260903A: Liverpool Telescope optical observations
  24. GRB 260903A: SAO RAS optical observations
  25. EP260903a: EP-WXT detection of a fast X-ray transient
  26. GRB 260903A: OHP/T193 optical afterglow detection
  27. NuSTAR Transient 260828: SOAR Optical Upper Limits
  28. GRB 260831A: GECAM-B observation
  29. GRB 260903A: LCO optical counterpart detection
  30. EP260901a: SVOM/VT optical upper limits
  31. EP260901a: EP-FXT follow-up observation
  32. Konus-Wind detection of GRB 260829A
  33. GRB 260829A: SVOM/GRM observation
  34. GRB 260818A: ATCA detection of a candidate radio counterpart
  35. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  36. NuSTAR Transient 260828: LCO Optical Upper Limits
  37. EP260901a: EP-WXT detection of a fast X-ray transient
  38. GRB 260831B: LCO optical upper limits
  39. EP260830a: EP-WXT detection of a fast X-ray transient
  40. GRB 260827A: SVOM/GRM observation
  41. GRB 260831B: SVOM detection of a possible burst
  42. EP260727a: ATCA 10 GHz detection
  43. GRB 260825A: SVOM/GRM observation of a long burst
  44. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  45. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  46. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  47. GRB 260818B: Further EP-FXT observation
  48. GRB 260818B: VLT optical and nIR observations
  49. GRB 260818B: TNG NIR observations
  50. GRB 260818B: 6 GHz VLA observations
  51. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  52. GRB 260808B: SAO RAS observations of the optical rebrightening
  53. GRB 260822A: SVOM/ECLAIRs refined analysis
  54. GRB 260809A: SVOM/ECLAIRs refined analysis
  55. IceCube-Cascade 260824A: Upper limits from a search for additional neutrino events in IceCube
  56. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  57. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  58. EP260822a: EP-FXT non-detection and upper limit
  59. GRB 260822A: GOTO optical counterpart detection
  60. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  61. EP260822a: Einstein Probe detection of a fast X-ray transient
  62. GRB 260822A: LCO optical upper limits
  63. GRB 260822A: GROWTH-India Telescope Upper Limits
  64. IceCube-260821A: Upper limits from a search for additional neutrino events in IceCube
  65. GRB 260818B: SVOM/C-GFT optical upper limit
  66. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  67. EP detected a brightening of LMXB 1ES 1735-26.9
  68. GRB 260818A: J-band observations with WINTER
  69. GRB 260818B: SVOM/ECLAIRs refined analysis
  70. GRB 260818A: SVOM/ECLAIRs refined analysis
  71. GRB 260818B: NOT optical upper limits
  72. GRB 260810A: SVOM/GRM observation
  73. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  74. GRB 260818B: LCO optical upper limits
  75. EP260806a: SAO RAS multicolor optical observations
  76. GRB 260818A: LCO optical upper limits
  77. EP260812a: AbAO optical upper limit
  78. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  79. EP260806a: SVOM/ECLAIRs detection through targeted search
  80. EP260806a: NUTTELA-TAO optical observations
  81. EP260812a: AZT-22 optical upper limit
  82. EP260806a: WFST optical observations
  83. EP260812b: Optical upper limit with Kinder
  84. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  85. GRB 260808B: Liverpool Telescope further optical observations
  86. EP260812a: NOT and Liverpool Telescope upper limits:
  87. EP260812b: Liverpool Telescope observations
  88. EP260812a: refined analysis of the EP-WXT and autonomous EP-FXT observation
  89. EP260812a: SVOM/C-GFT optical upper limit
  90. EP260812b: COLIBRÍ optical observations
  91. EP260812b: SVOM/VT optical observation
  92. GRB 260808A: SVOM/GRM observation
  93. EP260812b: Einstein Probe detection of an X-ray transient
  94. EP trigger #01709278129 (EP260812b?): NOT optical counterpart
  95. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  96. GRB 260810A: AstroSat CZTI detection of a long burst
  97. EP260812a: Einstein Probe detection of an X-ray transient
  98. GRB 260809A: SAO RAS optical observations
  99. GRB 260808B: SAO RAS optical observations
  100. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5

Advanced

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