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"

32508 results found.

  1. LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
  2. AT2023sva / GRB230916B: GIT observations of the afterglow
  3. transient AT2023sva: A Binary Driven Hypernova with a possible associated supernova
  4. LIGO/Virgo/KAGRA S230927be: Updated Sky localization
  5. LIGO/Virgo/KAGRA S230927l: Updated Sky localization
  6. LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate
  7. LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
  8. Swift Triggers 1192740, 1192742 and 1192743 are not astrophysical events
  9. LIGO/Virgo/KAGRA S230922q: Updated Sky localization
  10. Konus-Wind detection of GRB 230919A
  11. LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
  12. GRB 230812B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  13. LIGO/Virgo/KAGRA S230924an: Updated Sky localization
  14. LIGO/Virgo/KAGRA S230924an: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  16. LIGO/Virgo/KAGRA S230922g: Updated Sky localization
  17. LIGO/Virgo/KAGRA S230922g: Identification of a GW compact binary merger candidate
  18. LIGO/Virgo/KAGRA S230922q: Identification of a GW compact binary merger candidate
  19. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  20. GRB 230918B: VLT/X-shooter classification of AT 2023tbf (GOTO23aky) as a dwarf nova
  21. IPN triangulation of GRB 230919A (short)
  22. LIGO/Virgo/KAGRA S230904n: Classification of the candidate AT2023rkw with DBSP
  23. GRB 230919A: Fermi GBM Observation
  24. Correction to Fermi GBM Statement for Trigger 716527670/230916144
  25. Fermi GBM Statement for Trigger 716527670/230916144
  26. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  27. LIGO/Virgo/KAGRA S230920al: Updated Sky localization
  28. LIGO/Virgo/KAGRA S230919bj: Updated Sky localization
  29. transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
  30. GRB 230812B : optical observations from MISTRAL at Observatoire de Haute-Provence
  31. GRB 230919A: AstroSat CZTI detection
  32. LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
  33. AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
  34. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  35. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  36. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  37. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT
  38. GRB 230918A (short): Glowbug gamma-ray detection
  39. AT 2023sva: NOT observations of the ZTF candidate afterglow
  40. GRB 230915A: Fermi GBM observation
  41. GRB 230812B: Radio observations with the uGMRT
  42. GRB 230917A: AstroSat CZTI detection
  43. Swift Triggers 1192480, 1192481, 1192482 and 1192483 are not astrophysical events
  44. GRB 230911A: Fermi GBM Observation
  45. LIGO/Virgo/KAGRA S230904n: Correction of the coordinates of the ZTF candidate counterpart
  46. Fermi-LAT gamma-ray observations of IceCube-230914A
  47. GRB 230911D: GRBAlpha detection
  48. Swift Triggers 1192234, 1192235 and 1192236 are not astrophysical events
  49. GRB 230906A: optical counterpart
  50. IceCube-230914A: Upper limits from a search for additional neutrino events in IceCube
  51. GRB 230911A: Swift-XRT afterglow detection
  52. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  53. GRB 230913A: Glowbug gamma-ray detection
  54. LIGO/Virgo/KAGRA S230914ak: Updated Sky localization
  55. LIGO/Virgo/KAGRA S230914ak: Identification of a GW compact binary merger candidate
  56. GRB 230913A: Fermi GBM Observation
  57. LIGO/Virgo/KAGRA S230904n: One ZTF candidate counterpart to coincident neutrino event
  58. GRB 230911A: Swift ToO observations
  59. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  60. Fermi GRB 230913A: Global MASTER-Net observations report
  61. GRB 230911A: GOTO optical counterpart candidate
  62. GRB 230908A: CALET Gamma-Ray Burst Monitor detection
  63. GRB 230911D: NuSTAR Detection of Prompt Emission
  64. GRB 230911B: AstroSat CZTI detection
  65. GRB 230911C: Swift-BAT refined analysis
  66. LIGO/Virgo/KAGRA S230911ae: Updated Sky localization
  67. GRB 230906A: Chandra detection of the X-ray afterglow
  68. Swift GRB 230911C: Global MASTER-Net observations report
  69. GRB 230911D: Fermi GBM observation
  70. IPN triangulation of GRB 230911D (long)
  71. GRB 230911D: Fermi-LAT detection
  72. GRB230911C: LCOGT Optical Upper Limits
  73. LIGO/Virgo/KAGRA S230911ae: Identification of a GW compact binary merger candidate
  74. GRB 230911C: Swift/UVOT Upper Limits
  75. GRB 230911B: GRBAlpha and VZLUSAT-2 joint detection
  76. GRB 230911C: GOTO optical upper limits
  77. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  78. GRB 230911B: correction to the KW GCN 34659
  79. Konus-Wind detection of GRB 230811D
  80. GRB 230911C: Swift detection of a burst
  81. Fermi GRB 230911B: Global MASTER-Net observations report
  82. GRB 230906A: BlackGEM upper limits
  83. GRB 230903A: TESS observations of optical emission
  84. GRB 230906A: AstroSat CZTI detection
  85. GRB 230908A: GRBAlpha detection
  86. Glowbug gamma-ray detection GRB 230905B
  87. GRB 230906A: Swift/UVOT Upper Limits
  88. GRID detection of GRB 230827A
  89. GRB 230818A: radio observation with the VLA
  90. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  91. GRB 230906A: Swift-XRT observations
  92. Konus-Wind detection of GRB 230906A (short)
  93. IPN triangulation of GRB 230906A (short)
  94. GRB 230906A: Swift ToO observations
  95. GRB 230905B: AstroSat CZTI detection
  96. Fermi GRB 230906A: Global MASTER-Net observations report
  97. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  98. LIGO/Virgo/KAGRA S230904n: Updated Sky localization and EM Bright Classification
  99. GRB 230903A: VLT/X-shooter optical observations
  100. GRB 230903A: Swift-BAT refined analysis

Advanced

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