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"
  1. Search for SN light in XRF 040912 with MEGACAM
  2. GRB 040916: Afterglow Color at Early Times
  3. GRB 041006 Optical afterglow observations
  4. IBAS GRB Alert # 2010
  5. GRB 041006: BR observations with VATT
  6. GRB 041006: Redshift confirmed
  7. GRB041006: Liverpool Telescope optical observations
  8. GRB 041006: Colour measurement
  9. GRB041006: break in the light curve
  10. GRB 041006: Radio Observations
  11. GRB041006, further submilllimetre observations
  12. GRB 041006 : optical follow-up observation at Lulin Observatory
  13. GRB 041006 : Optical follow-up observation at TAROT
  14. GRB041006: Optical photometry and spectroscopy at TNG
  15. GRB 041006: presice astrometry
  16. GRB041006 (= H3570): Chandra Observations In Progress
  17. GRB 041006 : optical observation at Bisei
  18. GRB041006, optical I observation
  19. GRB041006 (=HETE3570): optical observations
  20. ROTSE-IIIa Observations of GRB 041006
  21. GRB041006, optical observation
  22. GRB041006, submillimetre observations
  23. GRB041006: MASTER optical observations
  24. GRB041006,optical observation
  25. GRB 041006: Optical decay
  26. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  27. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  28. GRB041006: Fading of optical afterglow candidate
  29. GRB 041006 : Optical follow-up observation at KISO
  30. GRB 041006: Finding chart
  31. GRB 041006: Optical afterglow candidate
  32. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  33. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  34. XRF 020903: Observations of the Host Galaxy (authors)
  35. XRF 020903: Observations of the Host Galaxy
  36. SGR 1806-20 still active
  37. GRB 040924: Second Epoch WSRT Radio Observations
  38. radio observations, GRB 040924
  39. IBAS Alert 1991. Not a real GRB
  40. GRB040929,optical observation
  41. GRB040929: MASTER optical observations
  42. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  43. GRB040924,optical observation
  44. GRB040924, RTT150 optical observation
  45. GRB040924,optical observation
  46. GRB 040924: detection of possible host galaxy by Subaru
  47. GRB040924, RTT150 optical observation
  48. GRB040924: KAIT observations
  49. GRB040924: Afterglow magnitude at t=17.5hr
  50. GRB 040924: WSRT Radio Observations
  51. GRB 040924: NIR finding chart
  52. GRB040924 : Optical candidate observations at Lulin observatory
  53. GRB040924 : Optical candidate observations at Lulin observatory
  54. GRB 040924: Subaru NIR observation
  55. GRB040924: Optical afterglow properties
  56. GRB 040924: RTT150 optical observations
  57. GRB 040924, optical follow-up
  58. GRB040924: MASTER: OT decay
  59. GRB040924: MASTER Optical observations
  60. IPN triangulation of GRB040924 (H3564)
  61. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  62. GRB040924 (H3564): Optical afterglow candidate
  63. XRF 040912: Radio Observations
  64. XRF 040916: Radio Observations
  65. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  66. XRF040916: continuing decay of OT
  67. TAROT Observations of GRB 040916 (HETE #3558)
  68. GRB040912(=H3557): Candidate Optical Afterglow
  69. XRF040916, optical observations
  70. XRF040916: Optical Transient Candidate by Subaru
  71. GRB040916 optical limits 17 min after GRB
  72. XRF 040912, identification of CXO sources
  73. XRF 040912 (=H3557): Spectral and Temporal Properties
  74. XRF040916, Ic observations
  75. XRF040916: optical follow-up observations
  76. XRF040912, BVRcIc field calibration
  77. XRF040916, BVRcIc field calibration
  78. GRB040916: Archival optical observations
  79. XRF 040916, optical follow-up
  80. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  81. GRB040916: Optical observations
  82. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  83. GRB040916 (= H3558): Improved Localization from HETE WXM
  84. GRB040916 (= H3558): A Long XRF Localized by HETE
  85. GRB040912 (= H3557): Chandra Observations Scheduled
  86. GRB 040912: Optical Observations
  87. GRB/XRF040912,optical observations
  88. GRB 040912, BVRI observations
  89. Optical observations of GRB/XRF 040912 = HETE 3557
  90. An intense burst from SGR1806-20
  91. GRB040912 : Kiso Optical follow-up observation
  92. IBAS GRB Alerts 1978-1980
  93. Optical observations of field of GRB040912
  94. HETE 3557: Optical observations
  95. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  96. GRB 040827: XMM-Newton data
  97. GRB040903 - A XRF?
  98. GRB040827: analysis of the XMM-Newton observation
  99. GRB040903, REM near-IR observation
  100. GRB 040903 - INTEGRAL data analysis

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