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"

28083 results found.

  1. Swift Detection of the Burst GRB050509
  2. GRB 050505: early time observations
  3. GRB 050505, simultaneous optical observation
  4. GRB050505: AAVSO observations
  5. GRB050416A : 1 GHz limit from GMRT
  6. GRB050505: Optical Afterglow Candidate
  7. GRB050505 Swift-BAT refined analysis
  8. GRB 050416b:Swift XRT afterglow upper limits
  9. GRB 050416b:Swift XRT afterglow upper limits
  10. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  11. GRB050502b: Afterglow Confirmation
  12. GRB050502: P200 Observations (Correction)
  13. GRB050502: P200 Observations
  14. GRB 050504 : R band observation at Lulin observatory
  15. Swift UVOT observation of GRB 050504
  16. GRB 050504, R band Observations
  17. GRB 050502b, V band Observations
  18. GRB050504: P60 Observations
  19. GRB 050504: A long GRB detected with INTEGRAL
  20. GRB (?) 050504: IR Observations, Intriguing Source
  21. GRB 050502b, Optical observations
  22. GRB050502a: P60 Observations (Correction)
  23. GRB050502a: P60 Observations
  24. Renewal of SGR 1806-20 activity
  25. GRB050502B Swift-BAT refined analysis
  26. Swift UVOT refined analysis
  27. GRB 050502a : R band observation at Lulin observatory
  28. GRB 050502b : optical observation at Lulin observatory
  29. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  30. Swift Detection of the Bright Burst GRB050502b
  31. GRB 050502: INTEGRAL results
  32. GRB 050502: ROTSE-III Detection of Possible Counterpart
  33. Swift/BAT possible detection of a weak burst GRB050430
  34. GRB050416a: Radio Detection
  35. GRB 050422: Swift-UVOT observation
  36. GRB 050422: Swift-BAT refined analysis
  37. Swift Detection of GRB 050422
  38. GRB 050421: SLOTIS observations
  39. GRB 050421: Further Analysis of IR imaging
  40. GRB050421: Radio Observations
  41. GRB050421: Radio Observations
  42. GRB 050421: IR Observations
  43. GRB 050421: Swift-BAT refined analysis
  44. GRB050421
  45. GRB 050421: early Swift XRT analysis results
  46. GRB 050421: NIR observations
  47. GRB050421: P60 Observations
  48. GRB 050421: BOOTES-2 simultaneous optical observations
  49. GRB 050416b: Tentative Swift XRT Position
  50. GRB 050315: potential host galaxy
  51. GRB050326: analysis of the XMM-Newton observation
  52. GRB050418: Null Optical Observations
  53. GRB050416A, optical observations
  54. GRB 050418: Swift-BAT refined analysis
  55. GRB 050416: Mitsume optical observation
  56. GRB050416B: IR observations
  57. GRB050412: Radio Observations
  58. GRB 050416: Swift/UVOT detection of afterglow emission
  59. GRB050416: Refined Swift-XRT analysis
  60. GRB 050416,optical observation
  61. GRB050416: P200 NIR Observations
  62. GRB 050416: Radio observations
  63. Swift BAT/XRT Detection of GRB 050416
  64. GRB 050412: PROMPT VRcIc Observations
  65. GRB 050408: Kuiper 1.5m observations
  66. GRB 050412: early Swift XRT analysis results
  67. GRB 050412: Early Optical/Ultraviolet Observations with
  68. GRB 050408: SDSS Field Calibration
  69. GRB050412: P60 Observations
  70. GRB 050412: Swift XRT Position
  71. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  72. GRB 050412: IR and Optical observations
  73. GRB 050412: IR Observations
  74. GRB050408: Radio Observations
  75. GRB 050401: Optical limit
  76. GRB050410: P60 Observations
  77. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  78. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  79. GRB050410: Radio Observations
  80. GRB050410: MASTER optical observations
  81. GRB 050410: Early observations with Swift-UVOT
  82. Swift-BAT detection of GRB 050410
  83. GRB 050408: Inconsistency of host galaxy identification
  84. GRB 050408: Subaru Observations
  85. GRB 050408: WIDGET simultaneous optical observations
  86. GRB 050408: Properties of the Host Galaxy
  87. GRB050408: Radio Observations
  88. GRB 050408: Swift XRT analysis
  89. GRB 050408: Optical limit at 20 min after the burst
  90. GRB050408: REM NIR and Optical observation
  91. GRB 050408,optical observation
  92. GRB 050408: Mercator Optical Observations
  93. GRB 050408: Optical afterglow confirmed
  94. GRB 050408: opitcal observation
  95. GRB 050408, optical observations
  96. GRB 050408 optical candidate
  97. GRB 050408: Swift XRT Position
  98. GRB050408: MASTER optical observations
  99. GRB050401: Radio Detection
  100. GRB 050406: early Swift XRT analysis results

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