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"

12090 results found.

  1. Konus-Wind detection of GRB 240603A
  2. Fermi GRB 240604A: Global MASTER-Net observations report
  3. GRB 240604A: GECAM detection of a long burst
  4. Fermi GRB 240603C: Global MASTER-Net observations report
  5. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  6. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  7. GRB 240529A: MASTER prompt OT detection
  8. GRB 240603A: GECAM detection of a short burst
  9. Fermi GRB 240602A: Global MASTER-Net observations report
  10. GRB 240529A: further SAO RAS optical observations
  11. Swift Trigger 1232465 is not a GRB
  12. GRB 240529A: 1.3m DFOT Optical observations
  13. GRB 240531A: AstroSat CZTI detection of a short burst
  14. Konus-Wind detection of GRB 240529A
  15. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  16. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  17. GRB 240529A: Skynet Optical Observations
  18. LXT 240528A: LEIA detection of a fast X-ray transient
  19. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  20. GRB 240529A: AstroSat CZTI detection
  21. GRB 240527B: Swift-XRT afterglow detection
  22. GRB 240529A: Swift detection of a burst with an optical counterpart
  23. Swift GRB240529.12: Global MASTER-Net observations report
  24. GRB 240527B: Fermi GBM Observation
  25. GRB 240527B: Fermi-LAT detection
  26. Fermi trigger No 738348224: Global MASTER-Net observations report
  27. Fermi trigger No 738330463: Global MASTER-Net observations report
  28. GRB 240523A: Swift-XRT refined Analysis
  29. Fermi trigger No 737996942: Global MASTER-Net observations report
  30. GRB 240521A: GECAM-B detection of a long burst
  31. GRB 240516B: AstroSat CZTI detection
  32. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  33. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  35. LIGO/Virgo/KAGRA S240520cv: Identification of a GW compact binary merger candidate
  36. GRB 240519A: AstroSat CZTI detection
  37. Fermi GRB 240517A: Global MASTER-Net observations report
  38. Konus-Wind detection of GRB 240513A
  39. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  40. Fermi trigger No 737523389: Global MASTER-Net observations report
  41. GRB 240516A: Swift detection of a burst
  42. Swift GRB240516.15: Global MASTER-Net observations report
  43. MAXI GRB240514.78: Global MASTER-Net observations report
  44. GRB 240514E: MAXI/GSC detection of a probable afterglow
  45. GRB 240514D: AstroSat CZTI detection
  46. GRB 240514C: Fermi GBM Final Real-time Localization
  47. Fermi GRB 240514B: Global MASTER-Net observations report
  48. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  49. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  50. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  51. LAT GRB240513.31: Global MASTER-Net observations report
  52. GRB 240513A: Fermi-LAT detection
  53. GRB 240511A: Fermi GBM Observation
  54. GRB 240511A: Swift-BAT refined analysis
  55. Fermi trigger No 737277727: Global MASTER-Net observations report
  56. GRB 240513A: AstroSat CZTI detection
  57. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  58. Fermi trigger No 737196587: Global MASTER-Net observations report
  59. Fermi trigger No 737168073: Global MASTER-Net observations report
  60. GRB 240511A: Swift-XRT refined Analysis
  61. Fermi trigger No 737152719: Global MASTER-Net observations report
  62. GRB 240511A: Swift detection of a burst
  63. GRB 240511A: Fermi GBM Final Real-time Localization
  64. Fermi trigger No 737111207: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  66. EP240506a: CrAO ZTSH optical upper limit
  67. EP240506a: EP-WXT detection of a new fast X-ray transient
  68. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  69. Fermi trigger No 736564880: Global MASTER-Net observations report
  70. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  71. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  72. Fermi GRB 240504A: Global MASTER-Net observations report
  73. Fermi trigger No 736472503: Global MASTER-Net observations report
  74. GRB 240503A: AstroSat CZTI detection
  75. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  76. GRB 240502C: GOTO possible optical counterpart candidates
  77. GRB 240502A long GRB detected by INTEGRAL
  78. Fermi GRB 240501A: Global MASTER-Net observations report
  79. Fermi trigger No 736197684: Global MASTER-Net observations report
  80. MeerKAT Discovery of a Probable Radio Counterpart to EP240414a
  81. GRB 240501B: AstroSat CZTI detection
  82. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  83. Fermi-LAT gamma-ray observations of IceCube-240424A
  84. LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  85. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  86. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  87. EP240426b: EP-WXT detection of a new fast X-ray transient
  88. GRB 240426A: AstroSat CZTI detection
  89. XMM-Newton observation of EP240426a
  90. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  91. EP240426a: GMG optical upper limit
  92. S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4
  93. S240422ed: MeerLICHT/BlackGEM photometry on AT2024hfx and archival ZTF detection
  94. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  95. LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
  96. GRB 240425A: Fermi GBM Final Real-time Localization
  97. Fermi trigger No 735697285: Global MASTER-Net observations report
  98. LIGO/Virgo/KAGRA S240422ed: Archival BlackGEM/MeerLICHT detections of AT 2024hdr & AT 2024hdq
  99. LIGO/Virgo/KAGRA S240413p: DESGW DECam Follow-Up
  100. LIGO/Virgo/KAGRA S240422ed: No significant counterpart candidates in HAWC observations

Advanced

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