Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32572 results found.

  1. Third epoch observations of SGR 1806-20 with VLA
  2. Second Epoch VLA observations of SGR 1806-20
  3. Second-epoch VLA observations of SGR 1806-20
  4. SGR1806: Detection of a Sudden Ionospheric Disturbance
  5. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  6. VLA observations of SGR 1806-20
  7. SGR1806 VLA Observations
  8. VLA observations of SGR 1806-20
  9. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  10. GRB 041217: Optical observations
  11. GRB041219, early time observations
  12. The giant outburst from SGR 1806-20
  13. IPN localization of giant flare from SGR1806-20
  14. GRB041228: ROTSE-III Optical Observations
  15. GRB041219; RXTE ASM Observations
  16. NIR Observations of GRB 041219
  17. GRB041226: ROTSE-III Optical Observations
  18. GRB041223: decay of the afterglow
  19. GRB041224: ROTSE-III Optical Observations
  20. GRB 041224: near-infrared observations with REM
  21. GRB 041223: XRT afterglow spectrum and light curve
  22. GRB 041223 Fluence measured by Swift-BAT
  23. GRB041223: optical and NIR observations with REM
  24. Swift-BAT Time History of GRB041219
  25. GRB 041219: TAROT optical observations
  26. GRB 041223: J-band observations of the afterglow
  27. GRB 041223: Detection of Optical Transient with LCO40
  28. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  29. GRB 041219c: PROMPT Observations
  30. GRB041223: ROTSE-III Optical Observations
  31. GRB 041218: optical observations
  32. Very high activity of SGR 1806-20
  33. GRB 041219: Second Epoch WSRT Radio Observations
  34. GRB 041219: WSRT Radio Afterglow Detection
  35. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  36. GRB 041218: Optical observations
  37. GRB 041219 : optical follow-up observations
  38. Deep RAPTOR observations during GRB 041219
  39. GRB 041218 Optical Observations
  40. GRB 041219 Optical Observations
  41. GRB041219: Optical Afterglow Detection
  42. GRB041219: Continued NIR Observations
  43. GRB 041219: Radio Afterglow Detection
  44. GRB 041218 : Radio Observations
  45. GRB 041218: R-band optical observations
  46. GRB041218: Liverpool Telescope optical observations
  47. GRB041218: optical observations
  48. GRB041219: Confirmed NIR Afterglow
  49. Swift-BAT detection of the bright long burst GRB041219
  50. GRB 041218: Optical Observation
  51. GRB 041219: Infrared Afterglow Candidate
  52. GRB041219, BVRcIc field calibration
  53. GRB 041219: Infrared Afterglow Candidate
  54. GRB041218, BVRcIc field calibration
  55. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  56. GRB 041217: PROMPT Observations
  57. GRB041218: optical observations
  58. GRB041217: optical limit 30 min after GRB
  59. GRB 041218; optical candidate
  60. GRB 041218: Optical observations
  61. GRB 041217: LCO40 Optical Observations and Possible Candidates
  62. GRB041217: Optical Observations
  63. GRB041217: NIR and optical observations with REM
  64. GRB041217: Infrared Observations
  65. GRB041217: The First GRB Located On-Board Swift
  66. GRB041211: Faulkes Telescope continued optical monitoring
  67. Optical Transient in Lynx not a GRB
  68. Optical transient (GRB?) in Lynx
  69. GRB041211: Continued P60 Observations
  70. GRB041211, Faulkes Telescope optical observation
  71. GRB041211, BVRcIc field calibration
  72. GRB 041211: Infrared Observations
  73. GRB 041211: Optical follow-up in East Asian region
  74. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  75. GRB041015: Near-Infrared observations
  76. GRB 040924: Afterglow Color
  77. GRB 041006: GETS Optical Afterglow Observation
  78. Summary of the recent bursts from SGR 1806-20
  79. GRB 041006: Optical Observations
  80. GRB041006, late-time optical photometry
  81. GRB041006: RTT150 Optical Observations
  82. GRB041015 : Multi epoch optical observations
  83. GRB041006: RTT150 Optical Observations
  84. GRB 041016: Optical limits
  85. GRB 041015: Optical Observations at Rikubetsu
  86. GRB041006: Near Infrared observations
  87. GRB040924, BVRcIc field calibration
  88. GRB 041015: Optical limit at Osaka University
  89. GRB041015 : Optical follow-up at Kiso
  90. GRB 041006 R observations in Loiano
  91. GRB041006: VLT observations of the afterglow and host galaxy
  92. GRB041006: Optical observations and Potential host galaxy
  93. GRB041006, BVRcIc field calibration
  94. GRB 040924: VLT spectroscopy
  95. GRB 041006: SARA afterglow observations
  96. GRB041006, optical observation in CrAO
  97. Search for SN light in XRF 040912 with MEGACAM
  98. GRB 040916: Afterglow Color at Early Times
  99. GRB 041006 Optical afterglow observations
  100. GRB 041006: BR observations with VATT

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