Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

21948 results found.

  1. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  2. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  3. EP240708a: NOT optical observations
  4. EP240708a: SVOM/C-GFT optical upper limit
  5. EP240708a: Optical upper limits with Kinder observations
  6. EP240708a: EP-WXT detection of a fast X-ray transient
  7. GRB 240705A: Fermi GBM Final Real-time Localization
  8. EP240703b: TRT optical upper limits
  9. EP240703a: TRT further optical observation
  10. EP240702a: TRT optical upper limits
  11. Konus-Wind detection of GRB 240627A
  12. IPN triangulation of GRB 240628B (short)
  13. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  14. EP240703c: Kinder optical follow-up and Swift XRT observations
  15. EP240703a: Liverpool Telescope optical follow-up observations
  16. EP240703a: Kinder optical follow-up observations
  17. EP240703c: EP-WXT detection of an X-ray transient
  18. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  19. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  20. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  21. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  22. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  23. EP240703b: EP-WXT detection of a fast X-ray transient
  24. Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
  25. EP240703a: EP-WXT detection of a fast X-ray transient
  26. EP240702a: GSP optical upper limit
  27. EP240702a: EP-WXT detection of a fast X-ray transient
  28. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  29. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  30. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  31. IPN triangulation of GRB 240619C
  32. GRB 240627A: NuSTAR Detection of the long GRB
  33. GRB 240615A: SAI CMO J- band observations
  34. EP240626a: Montarrenti Observatory optical upper limit
  35. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  36. EP240625a: GRANDMA Optical Upper Limits
  37. Konus-Wind detection of GRB 240619A
  38. EP240626a: EP-WXT detection of a fast X-ray transient
  39. EP240625a: NOT optical counterpart candidate
  40. GRB 240624B: GRBAlpha detection
  41. EP240625a: EP-WXT detection of a fast X-ray transient
  42. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  43. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  45. GRB240615A: Gemini-North observations of the BAT and XRT positions
  46. Fermi GRB 240624A: Global MASTER-Net observations report
  47. GRB240615A: Gemini-North observations of the BAT and XRT positions
  48. GRB 240619A: detection of a radio counterpart with AMI-LA
  49. GRB 240624A: Swift detection of a burst
  50. GRB 240619A: J-band detection with WINTER
  51. EP240618a: NOT optical counterpart candidate
  52. GRB 240529A: JinShan optical observations
  53. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  54. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  55. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  57. GRB 240619A: GRBAlpha detection
  58. GRB 240619C: NuSTAR automated detection of the GRB
  59. GRB 240619A: GOTO candidate optical afterglow
  60. GRB 240615A: NOT optical observations
  61. GRB 240619C: AstroSat CZTI detection
  62. EP240618a: TRT optical upper limit
  63. EP240617a: STEP/T80S optical limits
  64. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  65. LIGO/Virgo/KAGRA S240615dg: Updated Sky localization
  66. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  67. GRB240615A: 1.3m DFOT optical upper limit
  68. EP240617a: EP-WXT detection of a fast X-ray transient
  69. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  70. LIGO/Virgo/KAGRA S240618ah: Identification of a GW compact binary merger candidate
  71. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  72. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  73. GRB 240615A: J-band upper limits from WINTER
  74. GRB 240615A: FLWO-1.2m optical upper limits
  75. Konus-Wind detection of GRB 240615A (short/hard)
  76. GRB 240615A: GOTO optical upper limits
  77. LIGO/Virgo/KAGRA S240615ea: Identification of a GW compact binary merger candidate
  78. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  79. GRB 240603A: VZLUSAT-2 detection
  80. GRB 240612A: GRBAlpha detection
  81. Konus-Wind detection of GRB 240607A
  82. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  83. GRB 240529A: LBT optical detection and late temporal decay
  84. GRB 240529A : MITSuME Akeno optical afterglow detection
  85. Trigger 1236151: Swift detection of EXO 0748-676
  86. IPN triangulation of GRB 240607A
  87. Swift Trigger 1235109: consistent with noise and not astrophysical
  88. GRB 240607A: AstroSat CZTI detection of bright long burst
  89. GRB 240529A: radio detection with AMI-LA
  90. GRB 240606B: Swift-XRT afterglow detection
  91. Swift Trigger 1235109: a possible GRB 240606A
  92. GRB 240605C: Fermi GBM Final Real-time Localization
  93. GRB 240605B: Fermi GBM Final Real-time Localization
  94. GRB 240605A: Fermi GBM Final Real-time Localization
  95. GRB 240529A: SAO RAS optical observations
  96. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  97. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  98. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  99. GRB 240529A: MASTER prompt OT detection
  100. GRB 240529A: continued SAO RAS optical observations

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