Skip to main content
Circulars over Kafka event name backfill. 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"

18430 results found.

  1. GRB 120521B: GROND Upper limits
  2. GRB 120521A: XRT light curve (Correction to GCN 13326)
  3. GRB 120521A: Swift-XRT refined Analysis
  4. GRB 120521C: PAIRITEL NIR Upper Limits
  5. GRB 120521C: Enhanced Swift-XRT position
  6. GRB120521C: Liverpool Telescope observations
  7. GRB 120521C: TAROT Calern observatory optical observations
  8. GRB 120521C: Swift detection of a burst
  9. GRB 120521B: Swift-BAT refined analysis
  10. GRB 120521B: Swift-XRT refined Analysis
  11. Swift starts a new program to find fainter transients
  12. IPN Triangulation of GRB 120519A (short/hard)
  13. GRB 120521A: Swift/UVOT Upper Limits
  14. GRB 120521B: Enhanced Swift-XRT position
  15. GRB 120521A: Swift-BAT refined analysis
  16. GRB 120521B/Fermi Trigger 359284074: early MASTER-ICATE optical limit
  17. GRB120521B: Faulkes Telescope South observations
  18. GRB 120521B: TAROT La Silla observatory optical observations
  19. GRB 120521B: Swift detection of a burst
  20. GRB 120521A: Enhanced Swift-XRT position
  21. GRB 120521A: TAROT La Silla observatory optical observations
  22. GRB 120521A: Swift detection of a short burst
  23. GRB 120514A : Suzaku WAM observation of the prompt emission
  24. Swift Trigger 522245 is a noise fluctuation near IGR J17091-3624
  25. GRB 120514A: Swift/UVOT Upper Limits
  26. GRB 120514A: Swift-XRT refined Analysis
  27. GRB 120514A: Enhanced Swift-XRT position
  28. GRB 120514A: Swift-BAT refined analysis
  29. GRB 120514A: TAROT Calern observatory optical observations
  30. GRB 120514A: Swift detection of a burst
  31. GRB 120510A: Swift XRT and UVOT observations
  32. Fermi/GBM detection of a burst from the magnetar 1E 2259+5
  33. Swift detection of 4U 1630-47
  34. IPN Triangulation of bright GRB 120426A
  35. Swift Trigger 520928 is a noise event
  36. Swift Trigger 520928 is probably not a burst
  37. GRB 120422A: RAPTOR Limits During Gamma-ray Emitting Interval
  38. GRB 120422A GROND observations
  39. GRB 120422A: EVLA Detection
  40. GRB 120422A: Gemini redshift of candidate host
  41. GRB 120422A: Zadko observatory - Gingin optical observations
  42. GRB 120422A: Swift-XRT refined Analysis
  43. GRB 120422A: A Swift/UVOT Detection
  44. GRB 120422A: Enhanced Swift-XRT position
  45. GRB 120422A: Swift-BAT refined analysis
  46. GRB 120422A: Swift detection of a burst
  47. GRB 120419A: Swift-XRT and UVOT observations
  48. Swift Trigger 519874 is a noise event
  49. SGR1806-20, Swift-BAT refined analysis (Trigger 519868)
  50. Swift Trigger 519874 is probably a noise event
  51. Trigger 519868: Swift detection of SGR1806-20
  52. GRB 120404A: optical observations in Mondy observatory
  53. GRB 120404A: optical observations
  54. GRB 120404A, Optical Observations
  55. GRB 120404A: EVLA Detection
  56. GRB120404A: GROND observations show steeply decaying afterglow
  57. GRB120404A: MOA optical observations of the initial rise afterglow
  58. GRB 120404A: VLT/X-shooter redshift confirmation
  59. GRB 120404A: Swift/UVOT Detection
  60. GRB 120403B: Swift-XRT refined Analysis
  61. GRB 120404A: Swift-XRT refined Analysis
  62. GRB 120404A: Swift-BAT refined analysis
  63. GRB 120401A: GROND Detection of an optical/NIR afterglow candidate
  64. GRB 120404A: Enhanced Swift-XRT position
  65. GRB 120403B: TAROT La Silla observatory optical observations
  66. GRB 120403B: Fermi GBM Observation
  67. GRB 120404A: MASTER early OT limit
  68. GRB 120404A: Faulkes Telescope North afterglow confirmation
  69. GRB 120404A: Swift detection of a burst with an optical counterpart
  70. GRB 120403B: Swift-BAT refined analysis
  71. GRB 120403B: Swift/UVOT Upper Limits
  72. GRB 120403B: Enhanced Swift-XRT position
  73. GRB 120403A: Swift/BAT spectral lag analysis
  74. GRB 120403B: Swift detection of a burst
  75. BAT trigger 519207 was a burst from Cyg X-1, was not GRB 120402A
  76. GRB 120402A: optical upper limit
  77. GRB 120320A: optical upper limit in Mondy observatory
  78. GRB 120320A: early optical upper limit
  79. GRB 120403A: MASTER follow up observations
  80. GRB 120402A: MASTER follow up observations
  81. GRB 120403A, Swift-BAT refined analysis
  82. GRB 120326A: Bassano Bresciano Observatory - correction for GCN Cir 13178
  83. GRB 120403A: Swift detection of a burst
  84. GRB 120402A: Swift detection of a possible burst or noise
  85. GRB 120326A: Cima Rest and Bassano Brescia
  86. GRB 120401A: Swift-XRT refined Analysis
  87. GRB 120401A: Swift-BAT refined analysis
  88. GRB 120401A: Enhanced Swift-XRT position
  89. GRB 120401A: Prompt enhanced Swift-XRT position
  90. GRB 120401A: Swift detection of a burst
  91. GRB 120326A: EVLA Observations
  92. GRB 120324A: CrAO optical upper limit
  93. GRB 120326A: Bassano Bresciano Observatory lightcurve analisis
  94. GRB 120326A : Suzaku WAM observation of the prompt emission
  95. Swift trigger 518853 is most likely GX 301-2
  96. GRB 120326A: Bassano Bresciano Observatory optical observations
  97. Swift trigger 518853: MASTER-ICATE possible OT
  98. The Swift-XRT source associated with trigger 518853 is a cosmic ray
  99. Trigger 518853: Swift detection of a probable Galactic transient
  100. GRB 120327A: Zadko optical observations

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