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"

7407 results found.

  1. GRB 051105A, 2nd epoch optical observations
  2. GRB051103:_MASTER_optical_observations
  3. GRB 051105: Optical limit
  4. GRB051016B: optical observation
  5. GRB051028: optical observations
  6. GRB051028: confirmation of the afterglow
  7. GRB051028: WHT optical candidate
  8. GRB051028:MASTER observations
  9. GRB051028:MASTER optical observations
  10. GRB 051022: XRT Refined Spectral and Temporal Analysis
  11. GRB051021A: Swift XRT refined analysis
  12. GRB051021b: Magellan IR Imaging
  13. GRB 051021, SMARTS optical/IR observations
  14. GRB 051021: Optical observations
  15. GRB 051021: Optical observations and candidate afterglow
  16. GRB051021.63
  17. GRB051021.6: MASTER optical observation
  18. GRB 051016b: Optical limit
  19. Afterglow candidate of GRB 051016B observed at Lulin
  20. GRB 051016b: Gemini Near IR Observations
  21. GRB050805A: Rc optical observations
  22. GRB051008: optical candidate
  23. GRB051011: MASTER optical observation
  24. GRB051008 - Swift UVOT upper limits
  25. GRB 051008, optical observations
  26. GRB 051008: Swift UVOT Candidate
  27. grb test
  28. GRB050925: Faulkes Telescope North R-band limit
  29. GRB 050911, optical content of Swift/XRT error box
  30. GRB050911: Swift-XRT position
  31. GRB050908 : Swift-XRT refined analysis
  32. GRB 050908: Optical observations
  33. Gemini Spectroscopy of GRB 050908
  34. GRB 050908: P60 Confirmation of Optical Afterglow
  35. GRB 050908: Optical Observations
  36. GRB 050904: Subaru Optical Spectroscopy
  37. GRB 050906: Swift-BAT refined analysis
  38. GRB 050904: Keck I-band Imaging
  39. GRB 050904: TAROT optical measurements
  40. GRB 050827: Optical Limit
  41. GRB 050826 : Lulin R band observation
  42. GRB 050826: Optical Candidate
  43. GRB050824: MASTER final analysis of the OT observations
  44. GRB050824, I-band imaging
  45. GRB 050824: XRT refined analysis and possible afterglow detection
  46. GRB 050824: BAT refined analysis of a soft weak burst
  47. GRB050824: MASTER:OT decay
  48. GRB 050824 optical candidate
  49. GRB050814: P60 Optical Afterglow Candidate
  50. GRB 050813: Non-fading of afterglow candidate
  51. GRB050803: CrAO optical observations, no OT candidate
  52. GRB050802: TNG optical observations
  53. GRB 050803: RTT150 optical observations
  54. GRB050803: CrAO optical observations, possible OT candidate
  55. GRB 050803, optical observations
  56. GRB 050802: Swift/UVOT optical and UV detections
  57. GRB050801: Optical photometry and decay index
  58. GRB 050730, SMARTS optical/IR afterglow observations
  59. GRB050730: Liverpool Telescope optical observations
  60. GRB 050730, optical candidate
  61. GRB 050721a: Optical Observations
  62. GRB 050714a: Refined XRT analysis and afterglow confirmation
  63. GRB 050716; J-band observations
  64. GRB 050716 - UKIRT identification of candidate afterglow
  65. GRB 050716: Refined XRT analysis.
  66. GRB050716: Faulkes North Telescope observation
  67. GRB 050714B: refined XRT analysis
  68. GRB 050714B: candidate afterglow does not fade
  69. GRB 050709: optical afterglow candidate
  70. GRB 050714, R-band candidate
  71. GRB 050709: Spectroscopy
  72. GRB050713B: Faulkes North Telescope observation
  73. RBO RI observations of GRB 050713A
  74. GRB050709: Candidate X-ray Afterglow from Chandra
  75. GRB 050713: ARC NIR Detections and Identification of Fading
  76. GRB050712: UVOT candidate optical counterpart
  77. GRB 050626: Swift XRT observations
  78. GRB 050607: MDM Observations
  79. GRB 050603: Swift XRT Position
  80. GRB050528: BOOTES optical candidate (retraction)
  81. GRB050528: BOOTES optical candidate
  82. Possible GRB050528: no candidate from Liverpool Telescope
  83. GRB050525: Super-LOTIS observations
  84. GRB 050525a: Gemini/GMOS Spectra
  85. GRB050306: optical afterglow not confirmed
  86. GRB050525: Optical observations
  87. GRB 050525: Optical observation
  88. XRF050522: NIR observations of XRT candidate
  89. XRF 050522: Swift XRT refined analysis
  90. XRF050522: Optical Observations
  91. GRB050520: Liverpool Telescope follow-up
  92. XRF 050509C: REM NIR and Optical refined analysis
  93. GRB 050504: Swift XRT afterglow candidate has faded
  94. Chandra observation of GRB 050509b
  95. GRB 050509b: RAPTOR deep, early limits.
  96. GRB 050509b: Further Analysis of Keck LRIS Images
  97. GRB 050509b: Physical Properties of the Candidate Host galaxy
  98. GRB 050509B, Optical Observations
  99. GRB 050509b: Optical observations
  100. GRB 050509b: Optical Counterpart Candidate

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