Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

24375 results found.

  1. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  2. Distribution of IBAS Alerts for NON-GRB sources
  3. GRB 040924: Afterglow Color
  4. Summary of the recent bursts from SGR 1806-20
  5. GRB 041006: Optical Observations
  6. GRB041006, late-time optical photometry
  7. IBAS GRB Alert # 2034
  8. Bright bursts from SGR1806-20
  9. GRB041016: MASTER: Optical observations
  10. GRB041015: MASTER: Optical observations
  11. GRB041006: Fading X-ray Afterglow Observed with Chandra
  12. GRB 041015: Optical limit at Osaka University
  13. GRB 041015 - A long GRB detected by INTEGRAL
  14. GRB 040924: VLT spectroscopy
  15. Search for SN light in XRF 040912 with MEGACAM
  16. GRB 040916: Afterglow Color at Early Times
  17. IBAS GRB Alert # 2010
  18. GRB041006: Liverpool Telescope optical observations
  19. GRB041006: break in the light curve
  20. GRB 041006 : Optical follow-up observation at TAROT
  21. GRB041006: Optical photometry and spectroscopy at TNG
  22. GRB041006, optical I observation
  23. ROTSE-IIIa Observations of GRB 041006
  24. GRB041006: MASTER optical observations
  25. GRB041006,optical observation
  26. GRB 041006: Optical decay
  27. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  28. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  29. GRB 041006: Optical afterglow candidate
  30. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  31. SGR 1806-20 still active
  32. IBAS Alert 1991. Not a real GRB
  33. GRB040929,optical observation
  34. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  35. GRB040924,optical observation
  36. GRB 040924: detection of possible host galaxy by Subaru
  37. GRB040924: KAIT observations
  38. GRB040924: Optical afterglow properties
  39. GRB040924: MASTER: OT decay
  40. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  41. GRB040924 (H3564): Optical afterglow candidate
  42. TAROT Observations of GRB 040916 (HETE #3558)
  43. GRB040912(=H3557): Candidate Optical Afterglow
  44. XRF 040916, optical follow-up
  45. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  46. GRB040916 (= H3558): Improved Localization from HETE WXM
  47. An intense burst from SGR1806-20
  48. IBAS GRB Alerts 1978-1980
  49. HETE 3557: Optical observations
  50. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  51. GRB040903 - A XRF?
  52. GRB040827: analysis of the XMM-Newton observation
  53. GRB040903, REM near-IR observation
  54. IBAS Alert 1974. Not a real GRB
  55. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  56. Possible GRB 040903 - further analysis
  57. Possible GRB 040903 detected with INTEGRAL
  58. GRB 040827: optical and NIR observations at the VLT
  59. GRB 040827: K imaging - no evidence of variability
  60. GRB 040827 - Refined position
  61. GRB 040827 - A long GRB detected by INTEGRAL
  62. Increase of SGR 1806-20 activity
  63. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  64. MASTER: GRB040825b optical observation
  65. XRF040812: possible afterglow second Chandra observation
  66. GRB 040812: Second epoch CXO Observations
  67. GRB040823,optical observation
  68. Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
  69. Bursting activity from SGR 1806-20 detected with IBAS
  70. IPN/HETE localizations of GRB040810 (=H3489)
  71. Konus-Wind observation of GRB040810 (=H3489)
  72. GRB 040812: a long GRB detected by INTEGRAL
  73. GRB 040810: Optical observations of a limited region
  74. IPN/HETE triangulation of GRB040802 (=H3485)
  75. GRB 040730: a long GRB detected with INTEGRAL
  76. Ongoing activity of SGR 1806-20
  77. XRF 040701 - optical observations of the decaying Chandra source
  78. XRF040701: Second-Epoch Chandra Observations
  79. Cancellation of IBAS/INTEGRAL GRB alerts
  80. XRF040701: VLA Observations
  81. XRF040701: First-Epoch Chandra Observations
  82. IBAS Alert 1836: NOT a real GRB
  83. GRB040624, optical observations
  84. GRB040706:observation at University of Miyazaki
  85. GRB 040624: optical observations
  86. GRB 040624: optical observations at TNG and VLT
  87. MASTER: GRB 040624 optical observation after 0,48d
  88. GRB 040624: R-band observations
  89. GRB 040624 - A long GRB detected with INTEGRAL
  90. GRB 030329: Rebrightening of hyperluminal ejecta.
  91. IPN Summary of SGR1806-20 Activity in 2004
  92. SGR 1806-20: no IR variability of the proposed counterparts
  93. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  94. SGR 1806-20, potential NIR counterpart
  95. MASTER: HETE Alert 3274 optical observation
  96. Activivty of SGR 1806-20
  97. GRB 040511: NIR observations with REM
  98. GRB040511: Candidate optical/NIR afterglow
  99. IBAS GRB Alerts n.1785 to 1791
  100. GRB 040511: ROTSE-III Rapid Optical Upper Limits

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