Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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 060614: SMARTS host galaxy observations
  2. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  3. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  4. GRB 060109: Upper Limit on Host Galaxy
  5. GRB 060105: Upper limit on Host Galaxy
  6. GRB060614: Detection of the host galaxy but no supernova emission
  7. GRB 060614: redshift confirmation
  8. GRB 060614: Redshift
  9. Swift-BAT trigger 215279 is not a GRB
  10. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  11. GRB060614: Optical observations
  12. GRB 060614: spectroscopy
  13. GRB050326: Host Galaxy Candidates
  14. GRB050124: Possible Host Galaxy
  15. GRB050223: Host Galaxy
  16. GRB060512: near IR observations
  17. GRB060526: optical observations
  18. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  19. Konus-Wind observation of GRB 060614
  20. GRB060605: optical observation
  21. The Unusually Long-Lived Afterglow of GRB 060614
  22. GRB 060614: optical observations
  23. GRB 060605, optical observations
  24. GRB 060614, SMARTS optical/IR afterglow observation
  25. GRB060614: SSO 1m observations
  26. GRB060614: Watcher observation
  27. GRB 060614: Swift-BAT refined analysis
  28. GRB 060614: Swift/UVOT Observations
  29. GRB060614: Swift-XRT refined analysis
  30. GRB 060604, optical observations
  31. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  32. GRB 060602A: Swift/XRT analysis
  33. BAT Trigger #214277 is SGR 1900+14
  34. GRB 060610: KAIT observations
  35. GRB 060607: RTT150 optical observations
  36. GRB 070706B: Watcher upper limit
  37. GRB 060607B: Swift-BAT Refined Analysis
  38. GRB060602A: Swift/UVOT upper limits
  39. GRB 060607B: Swift detection of a burst
  40. GCN 060607: Swift-UVOT obswervations.
  41. GRB 060607: Swift-BAT Refined Analysis
  42. GRB 060607: optical limit by "Pi of the Sky"
  43. GRB 060607: Swift-XRT Team refined analysis
  44. GRB 060607: IR observations
  45. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  46. VLT/UVES observations of GRB 060607
  47. GRB 060607: PROMPT Observations
  48. GRB 060605: RTT150 optical observations
  49. GRB 060607: REM NIR afterglow
  50. GRB 060607: Swift detection of a burst with bright optical counterpart
  51. GRB 060522: PROMPT Optical Limits
  52. GRB 060605 BAT refined analysis
  53. GRB 060605: Xinglong TNT optical observations
  54. GRB060602B : REM infrared observations
  55. GRB060605: Swift/UVOT detections
  56. GRB 060605: Swift-XRT Team refined analysis
  57. SALT spectroscopy of GRB 060605
  58. GRB 060605: TNG optical observations
  59. GRB 060605: RTT150 optical observations
  60. GRB060605: Spectral Observations and Redshift
  61. GRB 060605: ROTSE-III Optical Counterpart
  62. GRB 060605: Swift detection of a burst with optical counterpart
  63. GRB 060605: ROTSE-III Detection of Optical Counterpart
  64. GRB060604: Swift/UVOT detections
  65. GRB 060604: redshift
  66. GRB 060512: Keck Redshift
  67. GRB 060604 optical photometry
  68. GRB 060604: Swift-XRT Team refined analysis
  69. GRB 060604: BAT refined analysis
  70. GRB 060604A: ROTSE-III Optical Limits
  71. GRB 060604: Swift detection of a burst with possible optical counterpart
  72. GRB 060602A: Swift-BAT Refined Analysis: Correction
  73. GRB 060602B: XMM-Newton Survey Source
  74. GRB 060602B: Swift-XRT Refined Analysis
  75. GRB 060602B: Swift-BAT Refined Analysis
  76. GRB 060602B: Swift/UVOT observations
  77. GRB 060602A: Swift-BAT Refined Analysis
  78. GRB 060602B: RTT150 optical observations
  79. GRB 060211A : WIDGET simultaneous optical observations
  80. GRB060602A: optical observations(/transient?)
  81. GRB 060526: Tautenburg Second Epoch Observations
  82. GRB060602A: Bootes-IR observations
  83. GRB 060602B: Swift detection of a burst
  84. GRB060602B: Watcher observations - no OT candidate
  85. GRB060602B: BOOTES-IR candidate afterglow
  86. GRB060602 - SDSS Pre-Burst Observations
  87. GRB 060602: Swift detection of a burst
  88. GRB 060502A: Optical afterglow observations
  89. GRB 060526: Break in X-ray light curve
  90. GRB 060526: RTT150 optical observations
  91. GRB060526, optical observations
  92. GRB 051227 : WIDGET simultaneous optical observations
  93. GRB 051028 : WIDGET pre-trigger limit
  94. GRB 060526: RTT150 optical observations
  95. GRB 060526: Multiple Optical Flares
  96. GRB060526: afterglow fitting and probable jet break
  97. GRB 060526: RTT150 optical observations
  98. GRB060526: Optical counterpart from MIRO
  99. GRB060502b: optical observations
  100. GRB 060526: RTT150 optical observations

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