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"

32548 results found.

  1. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  2. GRB 231111A: Mondy optical observations
  3. GRB 231111A: GECAM-C detection of a long burst (correction)
  4. GRB 231110A: GECAM-B detection (correction)
  5. GRB 231111A: GECAM-C detection of a long burst
  6. GRB 231110A: GECAM detection
  7. GRB 231110A: GOTO optical upper limits
  8. GRB 231110A: SAO RAS optical observations
  9. GRB231111A: YAHPT Observations
  10. GRB231111A: GIT confirmation of the optical afterglow
  11. GRB 231111A: MASTER OT earlier detection
  12. GRB 231111A: Nanshan/HMT optical observations
  13. GRB231110A: WFST Observation and upper limits
  14. LIGO/Virgo/KAGRA S231110g: Updated Sky localization
  15. LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
  16. IceCube-231103A: No candidates from the Zwicky Transient Facility
  17. LIGO/Virgo/KAGRA S231108u: Updated Sky localization
  18. Fermi GRB 231108A: Global MASTER-Net observations report
  19. LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
  20. GRB 231106A: AstroSat CZTI detection
  21. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  22. GRB 231104A: Swift-BAT refined analysis
  23. Fermi GRB 231106A: Global MASTER-Net observations report
  24. GRB 231104A: Wendelstein Optical/Infrared Observations
  25. GRB 231104A: NuSTAR Observation of the prompt emission
  26. GRB 231104A: 3.6m DOT optical upper limit
  27. IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
  28. Fermi-LAT gamma-ray observations of IceCube-231103A
  29. GRB 231104A: NOT upper limit
  30. GRB 231104A: Fermi GBM Observation
  31. Fermi GRB 231103A: Global MASTER-Net observations report
  32. LIGO/Virgo/KAGRA S231104ac: Updated Sky localization
  33. GRB 231104A: AKO Upper Limit
  34. GRB 231104A: AstroSat CZTI detection
  35. GRB 231104A: Fermi-LAT detection
  36. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  37. GRB 231104A: Swift/UVOT Upper Limits
  38. GRB231104A: LCOGT Optical Upper Limits
  39. Fermi-LAT gamma-ray observations of IceCube-231027A
  40. LIGO/Virgo/KAGRA S231102w: Updated Sky localization
  41. GRB 231101A: Glowbug gamma-ray detection
  42. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  43. LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
  44. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  45. GRB 231030B: GRBAlpha detection
  46. GRB 231030B: Fermi GBM Detection
  47. GRB 231030B: AstroSat CZTI detection
  48. Fermi GRB 231030B: Global MASTER-Net observations report
  49. IPN triangulation of GRB 231020A
  50. GRB 231028A: Swift-BAT refined analysis
  51. IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
  52. GRB 231024A: AKO Optical Counterpart Candidate
  53. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  54. Fermi GRB 231030A: Global MASTER-Net observations report
  55. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  56. GRID detection of GRB 231020A
  57. GRB 231028A: AstroSat CZTI detection
  58. GRB 231028A: Glowbug gamma-ray detection
  59. GRB 231028A: Fermi GBM Detection
  60. Swift GRB 231028A: Global MASTER-Net observations report
  61. LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
  62. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  63. GRB 231028A: Swift detection of a burst
  64. GRB 231019A: Glowbug gamma-ray detection
  65. IC231004A: GRANDMA observations of AT2023uqf/ZTF23abidzvf candidate
  66. GRB 231025A: Fermi GBM Observation
  67. GRB 231024A: Fermi GBM Observation
  68. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  69. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  70. GRB 231024A: LCOGT and ZTF detections of the GOTO optical counterpart candidate
  71. GRB 231020A: AstroSat CZTI detection
  72. GRB 231020B: AstroSat CZTI detection
  73. GRB 231024A: GOTO optical counterpart candidate
  74. The photometry of the transient in Messier 31 field: GMG observation
  75. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  76. LIGO/Virgo/KAGRA S231020bw: Updated Sky localization
  77. GRB 231020A: Fermi GBM Detection
  78. GRID detection of GRB 231004A
  79. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  80. GRB 231019A: VZLUSAT-2 detection
  81. GRB 231018A: VZLUSAT-2 detection
  82. LIGO/Virgo/KAGRA S231020ba: Updated Sky localization and EM Bright Classification
  83. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  84. GRB 231015A: NuSTAR Detection of Prompt Emission
  85. Fermi GRB 231020A: Global MASTER-Net observations report
  86. LIGO/Virgo/KAGRA S231020bw: Identification of a GW compact binary merger candidate
  87. GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  88. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  89. GRB 231017A: 1.3m DFOT Optical upper limit
  90. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  91. IceCube-231004A: Upper limits from Fermi-GBM Observations
  92. GRB 231018A: GRBAlpha detection
  93. GRB 231018A: CALET Gamma-Ray Burst Monitor detection
  94. Fermi GRB 231019A: Global MASTER-Net observations report
  95. GRB 231018A: Glowbug gamma-ray detection
  96. Konus-Wind detection of GRB 231018A
  97. IPN triangulation of GRB 231018A
  98. GRB 231017A: Swift/UVOT Upper Limit
  99. GRB 230911C: ATCA detection of possible radio counterpart
  100. GRB 231017A: GOTO optical upper limits

Advanced

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