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"

3139 results found.

  1. GRB 070411: Tautenburg RRM Afterglow Confirmation
  2. GRB 070406: Xinglong TNT optical Upper Limit
  3. GRB 070318: Swift detection of a burst with an optical afterglow
  4. IPN localization of very bright long hard GRB 070207
  5. RHESSI Spectrum of GRB070125
  6. Konus-Wind observation of GRB 061222A
  7. GRB 061222b, SMARTS optical/IR afterglow observations
  8. GRB 061217: ROTSE-III Optical Limits
  9. GRB 061121: Second Epoch ATCA Radio Observations
  10. GRB 061126: Early Detection of the IR Afterglow
  11. GRB 061121: MDM Continued Monitoring
  12. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  13. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  14. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  15. GRB 060928: Swift observations
  16. GRB 060923A: Keck and Gemini Observations
  17. GRB 060923, Swift-BAT refined analysis
  18. GRB 060908: Swift/UVOT Observations
  19. GRB 060906: observations with FRAM
  20. GRB 060904B: RTT150 optical observations
  21. GRB060814: Break in the XRT light curve
  22. GRB 060805B: Swift/UVOT Upper Limits
  23. GRB060719: prompt NIR observations with REM
  24. GRB050326: Host Galaxy Candidates
  25. GRB050124: Possible Host Galaxy
  26. GRB050223: Host Galaxy
  27. GRB 060522: PROMPT Optical Limits
  28. GRB 060507: Swift-BAT Refined Analysis
  29. GRB 060502: Swift detection of a burst with an optical counterpart
  30. GRB060428B, optical observation
  31. GRB 060428A: Refined analysis of the Swift-BAT burst
  32. GRB 060421: TTT Observations
  33. GRB060413: Swift/UVOT upper limits
  34. GRB 060413: Swift detection of a burst
  35. SGR 1900+14: BAT observations
  36. HETE Trigger 4043: ROTSE-III Optical Limits
  37. H4043, an unusual high-energy transient observed by HETE
  38. GRB 060322: Confirmation of Swift XRT afterglow
  39. GRB 060322: Swift XRT afterglow candidate
  40. GRB 060319: Swift detection of a burst
  41. Bright short hard GRB 060303: IPN localization and Konus spectrum
  42. GRB 060218/SN 2006aj: RBO optical observations
  43. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  44. GRB 050826: Optical Afterglow and Host Galaxy
  45. GRB 060211: Swift detection of a long burst
  46. GRB 060130: PROMPT Observations
  47. GRB 060124: Swift-BAT detection of a burst
  48. GRB 060116: IR Candidate Afterglow
  49. GRB 060115: OT photometry with MITSuME
  50. Swift Trigger 172767 is not a GRB
  51. GRB 051105b: ART optical limits
  52. SGR 1806-20: continued moderate activity seen with INTEGRAL
  53. GRB 051022 Chandra Observations scheduled
  54. GRB051021b: Magellan IR Imaging
  55. GRB051008: optical candidate
  56. GRB051008: optical observation
  57. GRB051008: Radio Observation
  58. GRB 051008: Swift XRT position
  59. GRB 051008: Swift UVOT Candidate
  60. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  61. GRB 051001: Swift Detection of a Burst
  62. GRB050922B: Swift UVOT early upper limits.
  63. GRB 050922B: optical limit
  64. GRB050922B: Swift-BAT detection of a weak long burst
  65. Swift-BAT trigger 155764 is not a GRB
  66. Swift-BAT trigger 155764 is probably not a GRB
  67. GRB 050915: Swift detection of a GRB
  68. GRB050908: VLT R-band decay index.
  69. GRB 050908: Swift detection of a burst
  70. GRB050904: Optical Observations
  71. GRB 050826: Optical Candidate
  72. GRB050824: MASTER:OT decay
  73. GRB 050820: Swift detection of a GRB
  74. GRB050814: P60 Optical Afterglow Candidate
  75. Retraction of Swift Trigger 149131 (GRB 050805B)
  76. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  77. GRB 050802 : Lulin Optical follow-up observation
  78. GCN 050801: early Swift XRT analysis results
  79. GRB 050730: Swift XRT afterglow observations
  80. GRB050721A: Swift-BAT detection of a weak burst
  81. GRB 050626: Swift XRT observations
  82. GRB 050701: Swift XRT afterglow position
  83. Swift trigger 143708 is really GRB 050701
  84. GRB050603: Fading Afterglow observed by Swift UVOT
  85. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  86. GRB050502b: Early Observation
  87. GRB 050509a: Swift-BAT refined analysis
  88. GRB 050509A: Optical observations
  89. GRB 050509a: Swift XRT Position
  90. GRB 050502a: Swift XRT Upper Limit
  91. GRB 050502a: Optical Observations
  92. GRB 050504: Swift XRT position
  93. GRB050502A: Optical Observations
  94. GRB 050502: Confirmed variability of the afterglow candidate +
  95. GRB050502 - Correction on the Optical Candidate from the Liverpool
  96. GRB050502 - Optical Candidate from the Liverpool Telescope
  97. GRB 050502: ROTSE-III Detection of Possible Counterpart
  98. GRB 050422: Swift-BAT refined analysis
  99. Swift Detection of GRB050421
  100. GRB 050416: Radio 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