Skip to main content
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"

20857 results found.

  1. GRB041228: ROTSE-III Optical Observations
  2. GRB041228: Swift-BAT detection of a burst
  3. GRB041219; RXTE ASM Observations
  4. GRB041226: ROTSE-III Optical Observations
  5. GRB041226: Swift-BAT detection of a burst
  6. GRB041223: decay of the afterglow
  7. GRB041224: ROTSE-III Optical Observations
  8. GRB 041224: near-infrared observations with REM
  9. GRB041224: Swift-BAT detection of a soft burst
  10. GRB041223: optical and NIR observations with REM
  11. GRB 041219: TAROT optical observations
  12. GRB 041218: TAROT optical observations
  13. GRB 041223: J-band observations of the afterglow
  14. GRB 041219c: PROMPT Observations
  15. GRB041223: ROTSE-III Optical Observations
  16. GRB041223: Swift-BAT detection of a bright long burst
  17. GRB 041218: optical observations
  18. GRB 041219 : optical follow-up observations
  19. GRB 041218 Optical Observations
  20. GRB041219: Continued NIR Observations
  21. GRB 041219 ,optical observation
  22. GRB 041219: Radio Afterglow Detection
  23. GRB 041218 : Radio Observations
  24. GRB 041218: R-band optical observations
  25. GRB041218: optical observations
  26. GRB041219: Confirmed NIR Afterglow
  27. Swift-BAT detection of the bright long burst GRB041219
  28. GRB 041219: Infrared Afterglow Candidate
  29. GRB041219, BVRcIc field calibration
  30. GRB 041219: Infrared Afterglow Candidate
  31. GRB041218, BVRcIc field calibration
  32. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  33. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  34. GRB 041217: PROMPT Observations
  35. GRB041217: optical limit 30 min after GRB
  36. GRB 041217: LCO40 Optical Observations and Possible Candidates
  37. GRB 041218 - A long GRB detected by integral
  38. GRB041217: NIR and optical observations with REM
  39. GRB041217: P60 Optical Observations
  40. GRB041217: Infrared Observations
  41. GRB041217: The First GRB Located On-Board Swift
  42. GRB041211: Faulkes Telescope continued optical monitoring
  43. Optical transient (GRB?) in Lynx
  44. GRB041211: RAPTOR observations
  45. GRB041211: Ashra Prototype optical observation
  46. GRB041211, BVRcIc field calibration
  47. GRB041211,optical observation
  48. GRB 041211: Infrared Observations
  49. GRB 041211: KAIT observations
  50. GRB 041211: Optical follow-up in East Asian region
  51. Triangulation of short GRB 041116 (large error box)
  52. GRB 040924: Afterglow Color
  53. GRB 041006: GETS Optical Afterglow Observation
  54. Summary of the recent bursts from SGR 1806-20
  55. GRB 041006: Optical Observations
  56. GRB041006, late-time optical photometry
  57. GRB041006: RTT150 Optical Observations
  58. HST Observations: XRF 040701 and 040812
  59. GRB 041016: BOOTES-2 simultaneous observation
  60. GRB041006: RTT150 Optical Observations
  61. GRB041016,optical observation
  62. GRB 041016: Optical limits
  63. GRB 041016:Optical limit during first minute
  64. GRB 041016: Optical limit
  65. GRB 041015 R band observations
  66. GRB040924, BVRcIc field calibration
  67. GRB041015,optical observation
  68. GRB041006: Fading X-ray Afterglow Observed with Chandra
  69. GRB 041015 - A long GRB detected by INTEGRAL
  70. GRB041006: Optical observations and Potential host galaxy
  71. GRB041006, BVRcIc field calibration
  72. GRB 041006: SARA afterglow observations
  73. GRB041006, optical observation in CrAO
  74. Search for SN light in XRF 040912 with MEGACAM
  75. GRB 040916: Afterglow Color at Early Times
  76. GRB 041006: BR observations with VATT
  77. GRB 041006 : Optical follow-up observation at TAROT
  78. GRB041006, optical I observation
  79. GRB041006 (=HETE3570): optical observations
  80. ROTSE-IIIa Observations of GRB 041006
  81. GRB041006: MASTER optical observations
  82. GRB041006,optical observation
  83. GRB041006: Fading of optical afterglow candidate
  84. GRB 041006: Optical afterglow candidate
  85. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  86. XRF 020903: Observations of the Host Galaxy
  87. radio observations, GRB 040924
  88. GRB040929,optical observation
  89. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  90. GRB040924,optical observation
  91. GRB040924,optical observation
  92. GRB040924: KAIT observations
  93. GRB 040924: WSRT Radio Observations
  94. GRB 040924: Subaru NIR observation
  95. GRB 040924, optical follow-up
  96. IPN triangulation of GRB040924 (H3564)
  97. XRF 040912: Radio Observations
  98. XRF 040916: Radio Observations
  99. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  100. XRF040916: continuing decay of OT

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