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"
  1. GRB 060206: RAPTOR observations of afterglow candidate variability.
  2. GRB 060206: High redshift burst
  3. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  4. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  5. GRB060206: Optical afterglow
  6. GRB060206: Swift-BAT detection of a burst
  7. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  8. GRB060203: WHT Z-band observations
  9. BAT GRB 060204C is probably not a GRB
  10. GRB060204C: optical observation
  11. GRB 060204B: BVRi-band detections of optical afterglow
  12. GRB 060204A: Swift XRT upper limit
  13. GRB 060204A: FRAM optical observations
  14. GRB060204B: Swift/UVOT refined analysis
  15. GRB 060204C: optical observations
  16. Swift XRT Observation of GRB 060204C
  17. GRB 060204B: Swift-BAT refined analysis
  18. GRB 060204B: ART early limit
  19. GRB060204B: Swift XRT Team Refined Analysis
  20. GRB 060204C: OSN limits
  21. GRB 060204b: Keck/LRIS Afterglow Confirmation
  22. GRB 060204C: BOOTES-IR optical limits
  23. GRB 060204C: Liverpool Telescopes optical limit
  24. GRB 060204C: ROTSE-III Optical Limits
  25. GRB 060204C: Swift-BAT detection of a burst
  26. GRB 060124: Radio Observations
  27. GRB060204B: Faulkes OT candidate
  28. GRB 060204B: ART optical limit
  29. GRB 060204A: further INTEGRAL results
  30. GRB060204B, optical observation
  31. GRB060204B - SDSS pre-burst observations
  32. GRB 060203: Swift-BAT refined analysis
  33. GRB 060204B: Swift detection of a burst
  34. GRB 060204: a long GRB detected by INTEGRAL
  35. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  36. GRB 060203: RTT150 optical observations
  37. GRB060203: Swift XRT Team Refined Analysis
  38. GRB060203 - Swift UVOT observation
  39. Swift-BAT trigger is GRB 060203
  40. GRB 060203: IR Counterpart
  41. GRB060203: Observations with SARA
  42. GRB 060203: P60 Confirmation of Optical Afterglow
  43. Possible GRB 060203: candidate optical counterpart
  44. Swift BAT Trigger 180151: Swift XRT source detection
  45. Possible GRB 060203: optical observations at Asiago
  46. GRB 060202: PROMPT Observations
  47. Swift-BAT trigger 180151 is unknown origin at this time
  48. GRB 060202: GETS observation
  49. GRB 060202: Gemini-N J, H, K_s observations
  50. GRB 060202 : Kiso B and R band limit
  51. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  52. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  53. GRB 060202: Refined analysis of the Swift-BAT burst
  54. GRB060202, optical observation
  55. GRB 060202: Swift/UVOT upper limits
  56. GRB 060202: Swift XRT Team Refined Analysis
  57. GRB 060202 : Lulin R and I band limit
  58. GRB060202: Faulkes North observation
  59. GRB 060202: Swift detection of a burst
  60. GRB 060121: Gemini Late-time Observations
  61. Erratum: SDSS pre-burst observations of GRB fields
  62. GRB 060130: PROMPT Observations
  63. GRB060130: Further R-band imaging
  64. GRB 060130: Swift/XRT observation
  65. GRB 051211A: MDM Observations
  66. GRB 060123: Gemini spectroscopy of the putative host galaxy
  67. GRB 060123: VLA Radio Observations
  68. GRB060130: Optical imaging
  69. GRB060130: REM infrared observations
  70. GRB 060130, SMARTS optical observations
  71. GRB 060130: FRAM optical observations
  72. GRB 060130: further INTEGRAL IBIS results
  73. GRB 060130: a long GRB detected with INTEGRAL
  74. Possible GRB 051221B: MDM Correction
  75. GRB050121: optical observation
  76. GRB050121b: optical observation
  77. GRB 060121: Confirmation of NIR Afterglow
  78. GRB060124: optical observation
  79. GRB060124: optical observations
  80. GRB 060123: Swift refined analysis of an unusual GRB
  81. GRB060124, BVRcIc field calibration
  82. GRB060105: refined analysis of the Suzaku observation
  83. GRB060124 optical observations
  84. GRB 060121: Probable Detection of NIR Afterglow
  85. GRB060124: optical observation
  86. GRB 060116 HST observations
  87. GRB 060124: HETE detection and spectrum of the main peak
  88. Refined XRT Position for GRB 060123
  89. Konus-Wind observation of GRB 060124
  90. GRB060124: detailed XRT analysis
  91. GRB 060124 Optical Observations
  92. GRB 060124: ART optical limits during the burst
  93. GRB060123: Optical and IR Imaging
  94. GRB 060123: P200 Observations
  95. GRB 060124: Keck optical spectrum
  96. GRB 060124: Keck Absorption Redshift
  97. GRB 060124: MDM Optical Spectrum
  98. GRB 060124: XRT refined analysis
  99. GRB 060124: R band Observations
  100. GRB 060124 : Optical observation at Xinglong and Kiso

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