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"

3321 results found.

  1. EP 241113a: LBT possible optical counterpart
  2. GRB 241113B: KAIT Optical Afterglow Candidate
  3. EP241113a: Global MASTER-Net observations report
  4. EP241113a : J-band observations with WINTER
  5. EP241113b: Global MASTER-Net observations report
  6. EP241113b/GRB 241113B: EP detection of GRB 241113B
  7. EP241113a: EP on-board trigger and autonomous follow-up observation
  8. Konus-Wind detection of GRB 241107A (short/hard)
  9. EP241107a: EP-FXT follow-up observations
  10. GRB 241025A: VZLUSAT-2 detection
  11. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  12. EP241109a: confirmation of a stellar flare by BOOTES-7
  13. EP241109a: EP on-board trigger and autonomous follow-up observation
  14. EP241107A: MASTER optical observations of xray transient
  15. EP241107a: Kinder optical follow-up observations
  16. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  17. EP241107a: AKO Optical Afterglow Follow-Up Observations
  18. EP241107a: GSP detects optical counterpart
  19. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  20. GRB 241105A: EP-FXT follow-up observations
  21. EP241107a: GIT optical observations
  22. EP241107a: Global MASTER-Net observations report
  23. EP241107a: SVOM/C-GFT optical observations
  24. EP241107a: AKO Optical Afterglow Detection
  25. EP241107a: EP on-board trigger and autonomous follow-up observation
  26. EP241101a: CrAO ZTSH optical observations
  27. Konus-Wind detection of GRB 241105A (short with extended emission)
  28. Konus-Wind detection of GRB 241021A
  29. GRB 241104A: Swift-XRT observations
  30. GRB 241104A: Fermi GBM Observation
  31. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  32. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  33. EP241104a: EP detection of GRB 241104A X-ray emission
  34. EP241101a: EP-FXT observations update
  35. EP241103a: GOTO optical upper limit
  36. EP241101a: Possible detection of an optical counterpart with FTW
  37. EP241103a: Swift XRT detection and improved X-ray position
  38. EP241101a: Optical upper limits with Kinder observations
  39. EP241103a: Gemini optical limits
  40. EP241103a: EP observation update
  41. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  42. EP241103a: GSP optical upper limit
  43. EP241103A: LCO optical observations
  44. EP241103a: Global MASTER-Net observations report
  45. EP241103a: an X-ray transient detected by Einstein Probe
  46. EP241101a: Global MASTER-Net observations report
  47. EP241101a: BOOTES-7 optical upper limit
  48. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  49. EP241101a: EP-WXT detection of a fast X-ray transient
  50. EP241021a: Upper limit from Konus-Wind observations
  51. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  52. EP EP241030a: Global MASTER-Net observations report
  53. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  54. EP241021a: Swift-UVOT detection
  55. Konus-Wind detection of GRB 241030A
  56. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  57. EP241026b: EP-FXT follow-up observation
  58. EP241021a: ATCA radio observations
  59. EP 241026b: LBT possible optical counterpart (brightening source)
  60. GRB 241026A: the 100th GRB detected by GRBAlpha
  61. Konus-Wind detection of GRB 241025A
  62. GRB 241026A: GECAM detection
  63. GRB 241026A: SVOM/GRM observation
  64. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  65. EP 241026b: LBT optical observations
  66. EP241021a: e-MERLIN radio observation
  67. EP EP241026b: Global MASTER-Net observations report
  68. EP241026b: EP detection of a fast X-ray transient
  69. EP241021a: optical follow-up observations with Xinglong Observatory
  70. EP 241021a: Swift-XRT observations
  71. EP241021a: optical follow-up observations with the Liverpool Telescope
  72. EP241025a (GRB 241025A): EP observations update
  73. EP 241021A: Swift ToO observations
  74. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  75. GRB 241025A: TRT optical afterglow observation
  76. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  77. EP241021a: No Detection in Fermi-GBM Observation
  78. EP241021a: VLT/FORS2 redshift z = 0.75
  79. EP241021a: EP-FXT follow-up observation update
  80. EP241021a: Optical counterpart observations with the Liverpool Telescope
  81. EP241021a: Optical upper limits with Kinder observations
  82. EP241021a: TRT optical observations
  83. EP241021a: NOT likely optical counterpart
  84. EP EP241021a: Global MASTER-Net observations report
  85. GRB 241018A: EP-FXT afterglow detection
  86. EP241021a: GOTO optical upper limits
  87. EP241021a: EP detection of a fast X-ray transient
  88. Konus-Wind detection of GRB 241018A
  89. GRB 241001A: EP-FXT afterglow detection
  90. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  91. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  92. GRB 240930B: SVOM/C-GFT optical upper limit
  93. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  94. GRB 240930B / EP 240930a: SVOM/GRM observation
  95. Konus-Wind detection of GRB 240926A
  96. IPN triangulation of GRB 240930B / EP 240930a
  97. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  98. EP240930a: Liverpool Telescope observations
  99. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  100. EP trigger ID 01709064214: the X-ray transient is most likely a stellar flare event

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