Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28125 results found.

  1. GRB 260818B: TNG NIR observations
  2. MAXI GRB260827.40: Global MASTER-Net observations report
  3. GRB 260818B: 6 GHz VLA observations
  4. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  5. GRB 260808B: SAO RAS observations of the optical rebrightening
  6. EP260822a: Global MASTER-Net observations report
  7. EP Alert 260820.31: Global MASTER-Net observations report
  8. GRB 260807A: EP-FXT follow-up observations
  9. IceCube Alert 260825A: Global MASTER-Net observations report
  10. IceCube-Cascade 260824A: Upper limits from a search for additional neutrino events in IceCube
  11. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  12. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  13. GRB 260818A: further EP-FXT observations and X-ray afterglow confirmation
  14. EP260822a: EP-FXT non-detection and upper limit
  15. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  16. EP260822a: Einstein Probe detection of a fast X-ray transient
  17. GRB 260822A: LCO optical upper limits
  18. GRB 260822A: GROWTH-India Telescope Upper Limits
  19. Fermi-LAT Gamma-ray Observations of IceCube-260821A
  20. Fermi-LAT Gamma-ray Observations of IceCube-260807A
  21. IceCube-260821A: Upper limits from a search for additional neutrino events in IceCube
  22. GRB 260818B: VLA radio observations
  23. GRB 260818B: SVOM/C-GFT optical upper limit
  24. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  25. IceCube Alert 260821A: Global MASTER-Net observations report
  26. GRB 260820A: Insight-HXMT/HE detection
  27. EP detected a brightening of LMXB 1ES 1735-26.9
  28. GRB 260818A: J-band observations with WINTER
  29. GRB 260818A: SVOM/ECLAIRs refined analysis
  30. GRB 260818B: NOT optical upper limits
  31. GRB 260810A: SVOM/GRM observation
  32. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  33. GRB 260818B: LCO optical upper limits
  34. GRB 260818B: SVOM detection of a short burst
  35. EP260806a: SAO RAS multicolor optical observations
  36. GRB 260818A: LCO optical upper limits
  37. EP260812a: AbAO optical upper limit
  38. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  39. GRB 260810A: Insight-HXMT/HE detection
  40. GRB 260818A: SVOM possible detection of a long and faint GRB
  41. EP260806a: NUTTELA-TAO optical observations
  42. The EP-WXT trigger 01709281429 is likely a flaring star
  43. EP260812a: AZT-22 optical upper limit
  44. EP260806a: WFST optical observations
  45. EP260812b: Optical upper limit with Kinder
  46. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  47. GRB 260808B: Liverpool Telescope further optical observations
  48. GRB 260813A: BALROG localization (Fermi Trigger 808341387 / GRB 260813803)
  49. EP260812a: NOT and Liverpool Telescope upper limits:
  50. EP260812b: Liverpool Telescope observations
  51. EP260812b: GOTO detection of the optical counterpart
  52. EP260812a: refined analysis of the EP-WXT and autonomous EP-FXT observation
  53. EP260812a: SVOM/C-GFT optical upper limit
  54. EP260812b: COLIBRÍ optical observations
  55. EP260812b: SVOM/VT optical observation
  56. GRB 260808A: SVOM/GRM observation
  57. EP260812b: Einstein Probe detection of an X-ray transient
  58. EP trigger #01709278129 (EP260812b?): NOT optical counterpart
  59. Fermi GBM Sub-Threshold Detection of GRB 260809A
  60. GRB 260810A: Glowbug gamma-ray detection
  61. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  62. GRB 260810A: AstroSat CZTI detection of a long burst
  63. EP260812a: Einstein Probe detection of an X-ray transient
  64. GRB 260809A: SAO RAS optical observations
  65. GRB 260808B: SAO RAS optical observations
  66. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
  67. EP260806a: MAO/AZT-22 optical observations
  68. IceCube-260807A: Upper limits from a search for additional neutrino events in IceCube
  69. GRB260808B: MAO/AZT-22 optical observations
  70. GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
  71. GRB 260809A: J-band upper limit with WINTER
  72. GRB 260806A: Glowbug gamma-ray detection
  73. GRB260809A/EPF_J234751.2+210212: EP-FXT follow-up observation
  74. GRB 260809A: SVOM/COLIBRÍ (FM-GFT) optical observation
  75. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
  76. GRB 260809A: NOT optical observations
  77. GRB260809A: MAO/AZT-22 optical observations
  78. GRB260809A: OHP/T193 optical observations
  79. IceCube-260805A: Upper limits from a search for additional neutrino events in IceCube
  80. EP260809a: J-band upper limit with WINTER
  81. GRB 260808B: J-band upper limit with WINTER
  82. EP260809a:refined analysis of the EP-WXT and autonomous EP-FXT observation
  83. GRB 260809A: SVOM detection of a faint burst
  84. GRB 260808B: Liverpool Telescope optical observations
  85. GRB 260808B: NOT optical observations
  86. GRB 260808B: LCO optical observations
  87. GRB 260808A: NuSTAR detection of prompt emission
  88. EP260809a: COLIBRÍ optical observations
  89. EP260809a: LCO optical observation
  90. EP260809a: OHP/T193 optical observations
  91. GRB260808B: OHP/T193 optical observations
  92. GRB 260808B / EPF_J230056.0+082842: EP-FXT follow-up observation
  93. EP260809a: Einstein Probe detection of an X-ray transient
  94. GRB 260808B: SVOM/VT optical candidate from VHF data ( localization correction for GCN 45317 )
  95. GRB 260808B: SVOM/VT optical candidate from VHF data
  96. GRB 260808B: SVOM detection of a faint burst
  97. GRB 260808A: BALROG localization (Fermi Trigger 807850307 / GRB 260808119)
  98. Fermi GRB 260808A: Global MASTER-Net observations report
  99. IceCube Alert 260807A: Global MASTER-Net observations report
  100. GRB 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov