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"

37733 results found.

  1. GRB050509B: Optical observations at the Very Large Telescope
  2. GRB 050509b: No Optical Variability in XRT Error Circle
  3. GRB 050509a: Swift-BAT refined analysis
  4. GRB 050509c: ROTSE-III Optical Limits
  5. GRB 050509B: WSRT Radio Observations
  6. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  7. GRB 050505, early TAROT observation
  8. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  9. GRB 050509b: Further Analysis of Keck LRIS Images
  10. GRB050509c: REM NIR and Optical observations
  11. GRB 050509b: Physical Properties of the Candidate Host galaxy
  12. GRB 050505: SARA Observations
  13. Swift UVOT Follow-up Observations of GRB 050509B
  14. GRB 050509B, Optical Observations
  15. GRB 050509B: Swift/XRT refined analysis
  16. GRB 050509b: Optical observations
  17. GRB 050509b: Precision Astrometry
  18. GRB 050509b: Possible Optical Counterpart
  19. Keck/DEIMOS Spectrum of Possible Host Galaxy for GRB050509b
  20. GRB 050509A: Optical observations
  21. GRB 050509b: Optical Counterpart Candidate
  22. GRB 050509b: PAIRITEL and WIYN Observations
  23. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  24. GRB 050509b: optical observations
  25. GRB 050509b: Swift XRT Position
  26. GRB 050509B: ROTSE-III Optical Limits
  27. GRB 050509a: Swift XRT Position
  28. Swift-BAT detection of GRB 050507
  29. GRB 050505: Keck I-band Magnitude
  30. GRB 050505: early time observations
  31. GRB 050505 - Faulkes Telescope North observations
  32. GRB 050502a: Swift XRT Upper Limit
  33. GRB 050505, simultaneous optical observation
  34. GRB 050505: Further Swift UVOT observations.
  35. GRB050505: AAVSO observations
  36. GRB050416A : 1 GHz limit from GMRT
  37. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  38. GRB 050505 UVOT
  39. GRB050505: Optical Afterglow Candidate
  40. GRB 050505: Swift XRT Position
  41. GRB 050502a: Optical Observations
  42. GRB 050416b:Swift XRT afterglow upper limits
  43. GRB 050416b:Swift XRT afterglow upper limits
  44. GRB 050504: Swift XRT position
  45. GRB050502: P200 Observations (Correction)
  46. GRB050502: P200 Observations
  47. GRB 050504 : R band observation at Lulin observatory
  48. Swift UVOT observation of GRB 050504
  49. GRB 050504, R band Observations
  50. GRB 050502b, V band Observations
  51. GRB050504: P60 Observations
  52. GRB 050504: A long GRB detected with INTEGRAL
  53. GRB (?) 050504: IR Observations, Intriguing Source
  54. GRB 050502b, Optical observations
  55. GRB050502a: P60 Observations (Correction)
  56. GRB050502a: P60 Observations
  57. Renewal of SGR 1806-20 activity
  58. GRB 050502a: RBO Observations
  59. GRB 050502A: WSRT Radio Observations
  60. GRB050502A: Optical Observations
  61. Swift UVOT refined analysis
  62. Retraction of Swift-BAT trigger 116145
  63. GRB 050502a : R band observation at Lulin observatory
  64. GRB 050502b : optical observation at Lulin observatory
  65. GRB 050502b: Swift XRT Position
  66. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  67. GRB 050502: INTEGRAL results
  68. GRB050502: ANU 1m optical Observations
  69. GRB 050502: Confirmed variability of the afterglow candidate +
  70. GRB 050502: PAIRITEL IR Observations
  71. GRB050502 - Correction on the Optical Candidate from the Liverpool
  72. GRB 050502 - A long GRB detected with INTEGRAL
  73. GRB 050502: ROTSE-III Detection of Possible Counterpart
  74. Swift-BAT Trigger 115881 is not a real GRB
  75. Swift/BAT possible detection of a weak burst GRB050430
  76. GRB 050401: Rc observation
  77. GRB050416a: Radio Detection
  78. GRB 050422: Swift-UVOT observation
  79. GRB 050422: Swift-BAT refined analysis
  80. GRB 050422: Swift XRT Position
  81. Swift Detection of GRB 050422
  82. GRB 050421: NIR observations
  83. GRB 050416: Optical/NIR observations
  84. GRB 050421: SLOTIS observations
  85. GRB 050421: Further Analysis of IR imaging
  86. GRB050421: Radio Observations
  87. GRB050421: Radio Observations
  88. GRB 050421: Swift-UVOT observation
  89. GRB 050421: IR Observations
  90. GRB 050421: Swift-BAT refined analysis
  91. GRB 050421: ROTSE-III Optical Limits
  92. GRB 050421: NIR observations re-examination
  93. GRB 050421: early Swift XRT analysis results
  94. GRB 050421: NIR observations
  95. GRB050421: P60 Observations
  96. GRB 050421: BOOTES-2 simultaneous optical observations
  97. GRB 050421: Optical observations at the INT
  98. GRB 050416b: Tentative Swift XRT Position
  99. GRB 050315: potential host galaxy
  100. GRB 050412: Chandra observations

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