Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

26316 results found.

  1. GRB 050520: Swift XRT refined analysis
  2. XRF050509C: Chandra Afterglow Detection
  3. XRF050509c: Radio Observations
  4. GRB 050520: P200 Observations
  5. GRB 050520: TAROT optical limit
  6. GRB 050520: VLT/ULTRACAM observations
  7. XRF 050509c optical afterglow
  8. GRB 050509B and short GRB-SN association? (corrected)
  9. GRB 050509B and short GRB-SN association?
  10. GRB050502b: Early Observation
  11. GRB050509b, Bok telescope B-band imaging
  12. Refined Chandra analysis of GRB 050509b
  13. GRB050509b, SDSS pre-burst observations
  14. GRB 050509b: Keck/Chandra Cross-Correlation
  15. GRB 050509b: Keck/Chandra Cross-Correlation
  16. Chandra observation of GRB 050509b
  17. GRB 050509b: RAPTOR deep, early limits.
  18. GRB050509B: Optical observations at the Very Large Telescope
  19. GRB 050509b: No Optical Variability in XRT Error Circle
  20. GRB 050509a: Swift-BAT refined analysis
  21. GRB 050509c: ROTSE-III Optical Limits
  22. GRB 050505, early TAROT observation
  23. GRB050509c: REM NIR and Optical observations
  24. GRB 050509b: Physical Properties of the Candidate Host galaxy
  25. GRB 050505: SARA Observations
  26. GRB 050509B, Optical Observations
  27. GRB 050509B: Swift/XRT refined analysis
  28. GRB 050509b: Optical observations
  29. GRB 050509A: Optical observations
  30. GRB050509b: Radio Observations
  31. GRB 050509b: PAIRITEL and WIYN Observations
  32. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  33. Swift Detection of GRB050509b: A short duration burst
  34. Swift Detection of the Burst GRB050509
  35. GRB 050505: early time observations
  36. GRB 050505, simultaneous optical observation
  37. GRB050505: AAVSO observations
  38. GRB050416A : 1 GHz limit from GMRT
  39. GRB050505: Optical Afterglow Candidate
  40. GRB050505 Swift-BAT refined analysis
  41. GRB 050416b:Swift XRT afterglow upper limits
  42. GRB 050416b:Swift XRT afterglow upper limits
  43. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  44. GRB050502b: Afterglow Confirmation
  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. GRB050502B Swift-BAT refined analysis
  59. Swift UVOT refined analysis
  60. GRB 050502a : R band observation at Lulin observatory
  61. GRB 050502b : optical observation at Lulin observatory
  62. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  63. Swift Detection of the Bright Burst GRB050502b
  64. GRB 050502: INTEGRAL results
  65. GRB 050502: ROTSE-III Detection of Possible Counterpart
  66. Swift/BAT possible detection of a weak burst GRB050430
  67. GRB050416a: Radio Detection
  68. GRB 050422: Swift-UVOT observation
  69. GRB 050422: Swift-BAT refined analysis
  70. Swift Detection of GRB 050422
  71. GRB 050421: SLOTIS observations
  72. GRB 050421: Further Analysis of IR imaging
  73. GRB050421: Radio Observations
  74. GRB050421: Radio Observations
  75. GRB 050421: IR Observations
  76. GRB 050421: Swift-BAT refined analysis
  77. GRB050421
  78. GRB 050421: early Swift XRT analysis results
  79. GRB 050421: NIR observations
  80. GRB050421: P60 Observations
  81. GRB 050421: BOOTES-2 simultaneous optical observations
  82. GRB 050416b: Tentative Swift XRT Position
  83. GRB 050315: potential host galaxy
  84. GRB050326: analysis of the XMM-Newton observation
  85. GRB050418: Null Optical Observations
  86. GRB050416A, optical observations
  87. GRB 050418: Swift-BAT refined analysis
  88. GRB 050416: Mitsume optical observation
  89. GRB050416B: IR observations
  90. GRB050412: Radio Observations
  91. GRB 050416: Swift/UVOT detection of afterglow emission
  92. GRB050416: Refined Swift-XRT analysis
  93. GRB 050416,optical observation
  94. GRB050416: P200 NIR Observations
  95. GRB 050416: Radio observations
  96. Swift BAT/XRT Detection of GRB 050416
  97. GRB 050412: PROMPT VRcIc Observations
  98. GRB 050408: Kuiper 1.5m observations
  99. GRB 050412: early Swift XRT analysis results
  100. GRB 050412: Early Optical/Ultraviolet Observations with

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