Skip to main content
New! Circulars over Kafka, Heartbeat Topic, and Schema v4.1.0. 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').

17519 results found.

  1. GW s240422ed: Swift UVOT follow-up
  2. GRB 240712A: Swift/UVOT Upper Limits
  3. The EP-WXT source triggered on July 14th is likely a flaring star
  4. GRB 240713A: Tiled Swift observations
  5. GRB 240712A: Swift detection of a burst
  6. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  7. EP240708a: EP-WXT detection of a fast X-ray transient
  8. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  9. IPN triangulation of GRB 240628B (short)
  10. EP240703a and EP240703b: Swift/XRT upper limits
  11. EP240703c: Kinder optical follow-up and Swift XRT observations
  12. EP240703c: EP-WXT detection of an X-ray transient
  13. IPN triangulation of GRB 240627A
  14. EP240703b: EP-WXT detection of a fast X-ray transient
  15. EP240702a: Swift/XRT upper limit
  16. EP240703a: EP-WXT detection of a fast X-ray transient
  17. EP240702a: EP-WXT detection of a fast X-ray transient
  18. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  19. IPN triangulation of GRB 240619C
  20. GRB 240624A: Swift-BAT refined analysis
  21. Konus-Wind detection of GRB 240619A
  22. GRB240624A: Fermi GBM Observation
  23. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  24. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  25. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  26. Swift GRB 240624A: Global MASTER-Net observations report
  27. GRB 240624A: Swift detection of a burst
  28. GRB 240529A: JinShan optical observations
  29. IPN triangulation of GRB 240615A (short)
  30. EP240618a: Swift/XRT upper limit
  31. EP240617a: tentative Swift/XRT detection of the afterglow
  32. GRB 240619A: Swift-XRT probable afterglow detection
  33. GRB 240619A: Swift ToO observations
  34. GRB 240615A: NOT optical observations
  35. GRB 240615A: possible transient detection from Wendelstein observations
  36. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  37. GRB240615A: 1.3m DFOT optical upper limit
  38. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  39. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  40. GRB 240615A: J-band upper limits from WINTER
  41. GRB 240615A: Fermi GBM Observation
  42. GRB 240615A: Swift-XRT observations
  43. GRB 240615A: GECAM detection
  44. GRB 240615A: FLWO-1.2m optical upper limits
  45. Konus-Wind detection of GRB 240615A (short/hard)
  46. GRB 240615A: GOTO optical upper limits
  47. GRB 240615A: Swift ToO observations
  48. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  49. EXO 0748-676: Swift-BAT refined analysis
  50. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  51. GRB 240529A: LBT optical detection and late temporal decay
  52. GRB 240529A : MITSuME Akeno optical afterglow detection
  53. Trigger 1236151: Swift detection of EXO 0748-676
  54. IPN triangulation of GRB 240607A
  55. Konus-Wind detection of GRB 240606B
  56. GRB 240606B: Fermi GBM Observation
  57. Swift Trigger 1235109: consistent with noise and not astrophysical
  58. GRB 240606B: GECAM-B detection a long burst
  59. GRB 240606B: Swift-XRT afterglow detection
  60. Swift GRB240606.15: Global MASTER-Net observations report
  61. GRB 240606B: Swift ToO observations
  62. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  63. Swift Trigger 1235109: a possible GRB 240606A
  64. IPN triangulation of GRB 240531A (short)
  65. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  66. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  67. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  68. Swift Trigger 1232465: consistent with noise
  69. GRB 240603B: Swift detection of a possible burst
  70. GRB 240529A: MASTER prompt OT detection
  71. GRB 240529A: OSN optical detection
  72. Swift Trigger 1232465 is not a GRB
  73. GRB 240529A: 1.3m DFOT Optical observations
  74. Konus-Wind detection of GRB 240529A
  75. IPN triangulation of the initial episode of GRB 240529A
  76. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  77. GRB 240529A: Insight-HXMT/HE detection
  78. GRB 240529A: GROWTH-India optical follow-up
  79. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  80. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  81. GRB 240529A: Skynet Optical Observations
  82. GRB 240529A: Swift-BAT refined analysis
  83. GRB 240529A: Swift-XRT refined Analysis
  84. GRB240529A: BOOTES-6/DPRT optical detection
  85. GRB 240529A: Swift/UVOT Detection
  86. GRB 240529A: NOT optical observations
  87. GRB 240529A: AstroSat CZTI detection
  88. GRB 240529A: GOTO optical afterglow detection
  89. GRB 240527B: Swift-XRT afterglow detection
  90. GRB 240529A: Enhanced Swift-XRT position
  91. GRB 240529A: Swift detection of a burst with an optical counterpart
  92. Swift GRB240529.12: Global MASTER-Net observations report
  93. GRB 240527B: Fermi-LAT detection
  94. GRB 240523A: Swift-BAT refined analysis
  95. GRB 240523A: Swift-XRT refined Analysis
  96. GRB 240523A: Enhanced Swift-XRT position
  97. GRB 240523A: Swift detection of a burst
  98. GRB 240521B: Fermi GBM Observation
  99. GRB 240513A: Swift-XRT afterglow detection
  100. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst

Advanced

Download all Circulars as a .tar.gz archive:
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