Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. 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"

23706 results found.

  1. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  2. GRB 241026A: Swift/UVOT Upper Limits
  3. GRB 241029A: Swift-XRT observations
  4. GRB 241029A: Fermi GBM Observation
  5. GRB 241029A: GOTO optical afterglow detection
  6. GRB 241029A: MASTER early optical counterpart detection
  7. EP 241026b: LBT possible optical counterpart (brightening source)
  8. GRB 241029A: TRT optical afterglow candidate detection
  9. Fermi trigger No 751861204: Global MASTER-Net observations report
  10. GRB 240821A: Keck/LRIS spectroscopic observations
  11. GRB 241026A: the 100th GRB detected by GRBAlpha
  12. GRB 241026A: TNOT optical counterpart detection
  13. Konus-Wind detection of GRB 241025A
  14. GRB 241026A: GECAM detection
  15. GRB 241025A: further SAO RAS optical observations
  16. GRB 241026A: BTA and Zeiss-1000 optical observations
  17. GRB 241026A Fermi GBM Analysis
  18. GRB 241026A: BTA redshift identification of z = 2.79
  19. GRB 241026A: J-band observations with WINTER
  20. GRB 241025A: SAO RAS optical observations
  21. GRB 241026A: Las Cumbres optical detection
  22. EP241021a: further SAO RAS optical observations
  23. GRB 241026A: Swift-XRT refined Analysis
  24. EP EP241026b: Global MASTER-Net observations report
  25. GRB 241026A: KAIT optical observations
  26. Fermi trigger No 751616906: Global MASTER-Net observations report
  27. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  28. GRB 241026A: SAO RAS observations of possible optical afterglow
  29. Fermi GRB 241026A: Global MASTER-Net observations report
  30. GRB 241026A: Swift detection of a burst
  31. Swift GRB241026.95: Global MASTER-Net observations report
  32. EP241021a: optical follow-up observations with Xinglong Observatory
  33. GRB 241025A: COLIBRÍ Detection of the Afterglow
  34. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  35. Fermi trigger No 751563375: Global MASTER-Net observations report
  36. Fermi trigger No 751554401: Global MASTER-Net observations report
  37. EP 241021a: Swift-XRT observations
  38. Fermi GRB 241025A: Global MASTER-Net observations report
  39. Swift GRB 241025A: Global MASTER-Net observations report
  40. EP241025a (GRB 241025A): EP observations update
  41. GRB 241025A : SVOM/VT optical afterglow observations
  42. GRB 241025A: NOT spectroscopic redshift of z = 4.20
  43. GRB 241025A: DDOTI Afterglow detection
  44. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  45. GRB 241025A: TRT optical afterglow observation
  46. Fermi GRB 241024B: Global MASTER-Net observations report
  47. GRB 241025A: Swift detection of a burst with an optical counterpart
  48. EP241021a: No Detection in Fermi-GBM Observation
  49. Fermi trigger No 751449953: Global MASTER-Net observations report
  50. EP241021a: SAO RAS optical observations
  51. EP241021a: KAIT optical observations
  52. EP241021a: GSP detects optical candidate counterpart
  53. EP241021a: Optical upper limits with Kinder observations
  54. EP241021a: TRT optical observations
  55. EP241021a: NOT likely optical counterpart
  56. EP EP241021a: Global MASTER-Net observations report
  57. GRB 241018A: EP-FXT afterglow detection
  58. EP241021a: GOTO optical upper limits
  59. EP241021a: EP detection of a fast X-ray transient
  60. Konus-Wind detection of GRB 241018A
  61. GRB 241018A/sb24101802: Mephisto optical upper limit
  62. GRB 241018A: BOOTES-4/MET optical upper limit
  63. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  64. GRB 241018A: Swift-XRT observations
  65. GRB 241018A: REM optical/NIR upper limits
  66. GRB 241017A: SVOM/VT follow-up and optical upper limit
  67. GRB 241018A: SVOM/VT follow-up and optical candidate
  68. GRB 241018A: X-ray afterglow candidate observed by MXT
  69. GRB 241017A: Swift-XRT observations
  70. GRB 241001A: EP-FXT afterglow detection
  71. GRB241017A: TOO Observations by SVOM/MXT
  72. GRB 241017A: J-band upper limit from WINTER
  73. Fermi trigger No 750788395: Global MASTER-Net observations report
  74. Fermi GRB 241016B: Global MASTER-Net observations report
  75. Fermi GRB 241016A: Global MASTER-Net observations report
  76. IceCube Alert 241016.04: Global MASTER-Net observations report
  77. GRB 241010A: Swift-BAT refined analysis
  78. GRB 240916A: radio detection with the VLA
  79. GRB241013A: REM observations
  80. GRB 241013B: SVOM/GRM observation
  81. Fermi GRB 241013B: Global MASTER-Net observations report
  82. Integral GRB241013.04: Global MASTER-Net observations report
  83. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  84. GRB 241009A: GRANDMA optical upper limits
  85. GRB 241009A: Swift-XRT afterglow detection
  86. GRB 241010A: Swift-XRT refined Analysis
  87. Fermi trigger No 750211959: Global MASTER-Net observations report
  88. Swift GRB 241010A: Global MASTER-Net observations report
  89. Fermi trigger No 750291012: Global MASTER-Net observations report
  90. GRB 241010A: J-band observations with WINTER
  91. Fermi GRB 241010B: Global MASTER-Net observations report
  92. GRB 241010A: LCO optical observations
  93. GRB 241010A: Swift detection of a burst with an optical counterpart
  94. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  95. GRB 241006A: Swift-BAT refined analysis
  96. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  97. GRB 241008A: Fermi-LAT detection
  98. GRB 241002B: Swift-XRT afterglow detection
  99. LIGO/Virgo/KAGRA S241009an: Identification of a GW compact binary merger candidate
  100. Fermi GRB 241008A: Global MASTER-Net observations report

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