Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New! BOOM Notices and Schema v7.0.0. 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').
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"
  1. GRB 220611A: Swift-XRT refined Analysis
  2. GRB 220610B: AstroSat CZTI detection
  3. GRB 220611A: Enhanced Swift-XRT position
  4. GRB 220611A: Swift detection of a burst
  5. IPN triangulation of GRB 220609B
  6. Fermi GRB 220610A: Global MASTER-Net observations report
  7. GRB 220610A: Fermi GBM Final Real-time Localization
  8. Fermi trigger No 676537486: Global MASTER-Net observations report
  9. GRB 220609B: AstroSat CZTI detection
  10. GRB 220609B: CALET Gamma-Ray Burst Monitor detection
  11. Fermi trigger No 676366592: Global MASTER-Net observations report
  12. GRB 220608A: AstroSat CZTI detection
  13. GRB 220609A: Fermi GBM Final Real-time Localization
  14. GRB 220606A: Fermi GBM observation
  15. GRB 220606C: CALET Gamma-Ray Burst Monitor detection
  16. Fermi GRB 220608A: Global MASTER-Net observations report
  17. GRB 220608A: Fermi GBM Final Real-time Localization
  18. GRB 220606B: Gemini South Optical Observations
  19. MAXI GRB220607.31: Global MASTER-Net observations report
  20. MAXI GRB220607.41: Global MASTER-Net observations report
  21. GRB 220606B: Fermi GBM Observation
  22. GRB 220606B: Swift follow-up observations
  23. Konus-Wind detection of GRB 220601A
  24. GRB 220606A: Swift/BAT-GUANO detection
  25. GRB 220606B: GUANO coordinate correction to GCN 32167
  26. GRB 220527A: A BdHN I with a clear UPE phase
  27. GRB 220606B: Swift ToO observations
  28. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  29. Fermi GRB 220606B: Global MASTER-Net observations report
  30. GRB 220606B: Fermi GBM Final Real-time Localization
  31. GRB 220606A: Fermi GBM Final Real-time Localization
  32. IPN triangulation of GRB 220601A (long)
  33. Fermi trigger No 675992935: Global MASTER-Net observations report
  34. GRB 220603A: Swift/BAT-GUANO detection outside the coded FOV
  35. Fermi-GBM will trial new SAA regions from Tuesday June 7th
  36. GRB 220527A: MITSuME Akeno continued optical observation
  37. GRB 220527A: Lick 3m Optical Observations
  38. Konus-Wind detection of GRB 220528A
  39. IPN triangulation of GRB 220528A (short)
  40. GRB 220528A: Fermi GBM Observation
  41. Trigger 1108538: Swift detection of a burst from SGR J1935+2154
  42. Fermi GRB 220530A: Global MASTER-Net observations report
  43. Konus-Wind observation of GRB 220527A
  44. Swift trigger 1108515 is not an astrophysical event
  45. GRB 220530A: Fermi GBM Final Real-time Localization
  46. Correction to GCN 32148: Should be GRB 220528A
  47. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  48. GRB 220528A: Fermi GBM Final Localization
  49. GRB 220527A: AST3-3 Yaoan Optical Observation
  50. GRB 220527A: REM optical/NIR observations
  51. GRB 220527A: VLT/X-shooter spectroscopic redshift
  52. GRB 220527A: MeerLICHT afterglow observations
  53. Fermi trigger No 675411172: Global MASTER-Net observations report
  54. GRB 220527A: NOT optical photometry and spectroscopic redshift
  55. GRB 220527A: AstroSat CZTI detection
  56. GRB 220527A: CALET Gamma-Ray Burst Monitor detection
  57. GRB 220527A: MITSuME Akeno optical observation
  58. LAT GRB220527.39: Global MASTER-Net observations report
  59. GRB 220527A: Swift/UVOT detection
  60. GRB 220527A: Swift-XRT afterglow detection
  61. Swift trigger 1108208 is not an interesting astrophysical event.
  62. GRB 220527A: Fermi GBM Observation
  63. GRB 220527A: Swift ToO observations
  64. GRB 220527A: Fermi-LAT detection
  65. GRB 220527A: Fermi GBM Final Localization
  66. GRB 220527A: AGILE detection
  67. GRB 220521B: CALET Gamma-Ray Burst Monitor detection
  68. GRB 220525A: Fermi GBM Detection
  69. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 May 25
  70. GRB 220525A: CALET Gamma-Ray Burst Monitor detection
  71. GRB 220523B: CALET Gamma-Ray Burst Monitor detection
  72. Konus-Wind detection of GRB 220524B
  73. Konus-Wind detection of GRB 220525A
  74. Konus-Wind detection of GRB 220524A
  75. Swift GRB220526.48: Global MASTER-Net observations report
  76. Fermi GRB 220525A: Global MASTER-Net observations report
  77. IPN triangulation of GRB 220525A
  78. IPN triangulation of GRB 220524B
  79. Fermi-LAT Gamma-ray Observations of IceCube-220524A
  80. IPN triangulation of GRB 220524A
  81. IceCube-220524A: Upper limits from a search for additional neutrino events in IceCube
  82. GRB 220525A: BALROG localization (Fermi Trigger 675130259 / GRB 220525008)
  83. GRB 220525A: Fermi GBM Final Real-time Localization
  84. GRB 220521A: ATCA detection
  85. GRB 220521A: ALMA detection
  86. Konus-Wind detection of GRB 220522B
  87. IPN triangulation of GRB 220522B
  88. GRB 220521A: BOOTES-2/TELMA and CAHA 2.2m telescope optical upper limit
  89. Konus-Wind detection of GRB 220521B
  90. GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
  91. IPN triangulation of GRB 220521B
  92. GRB 220521A: ISON-Castelgrande observatory optical observations
  93. IceCube-220524A - IceCube observation of a high-energy neutrino candidate track-like event
  94. GRB 220521A: MITSuME Akeno optical upper limits
  95. Fermi GRB 220523B: Global MASTER-Net observations report
  96. GRB 220521A: Gemini Observations
  97. GRB 220523B: Fermi GBM detection
  98. GRB 220521A: MMT Afterglow Imaging
  99. GRB 220521A: REM optical/NIR upper limits
  100. GRB 220514A: Swift/BAT-GUANO detection outside the coded FOV

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