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"

24376 results found.

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

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