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"

27016 results found.

  1. GRB 050215b: Swift XRT Source Variability
  2. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  3. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  4. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  5. GRB 050215b, BOOTES-1B optical limit
  6. GRB050215B: ROTSE-III optical observations
  7. GRB050215A: ROTSE-III Optical Observations
  8. GRB050209: REM optical observations
  9. GRB 050209 Optical observations
  10. GRB050209: P60 Optical Observations
  11. GRB 050209: Optical observation
  12. GRB050128,optical observations
  13. GRB 050124 I-band observation
  14. GRB050124,optical observation
  15. GRB050124: Refined BAT position, spectral and fluence information
  16. GRB050123,optical observation
  17. GRB 050123: KAIT observations
  18. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  19. GRB 050117, I-band observations
  20. SGR1806: Detection of a Sudden Ionospheric Disturbance
  21. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  22. The giant outburst from SGR 1806-20
  23. Swift-BAT Time History of GRB041219
  24. GRB041220: Swift-BAT burst
  25. Deep RAPTOR observations during GRB 041219
  26. GRB041219c: Third Burst in One Day from Swift-BAT
  27. GRB 041219 ,optical observation
  28. GRB 041218: R-band optical observations
  29. Swift-BAT detection of the bright long burst GRB041219
  30. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  31. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  32. GRB041211: Continued P60 Observations
  33. GRB041211: RAPTOR observations
  34. GRB041211, BVRcIc field calibration
  35. GRB041211,optical observation
  36. GRB 041211: Infrared Observations
  37. GRB 041211: KAIT observations
  38. Distribution of IBAS Alerts for NON-GRB sources
  39. GRB 041006: GETS Optical Afterglow Observation
  40. Summary of the recent bursts from SGR 1806-20
  41. GRB041015, optical observation in CrAO
  42. Bright bursts from SGR1806-20
  43. GRB 041016: BOOTES-2 simultaneous observation
  44. GRB041016,optical observation
  45. GRB 041016: Optical limits
  46. GRB 041016:Optical limit during first minute
  47. GRB041016: MASTER: Optical observations
  48. GRB041006: Near Infrared observations
  49. GRB 041016: Optical limit
  50. GRB 041015 R band observations
  51. GRB040924, BVRcIc field calibration
  52. GRB041015: MASTER: Optical observations
  53. GRB041015,optical observation
  54. GRB041006: MASTER optical observations
  55. GRB041006,optical observation
  56. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  57. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  58. GRB040929,optical observation
  59. GRB040924,optical observation
  60. GRB040924: KAIT observations
  61. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  62. GRB040924 (H3564): Optical afterglow candidate
  63. XRF040912, BVRcIc field calibration
  64. XRF040916, BVRcIc field calibration
  65. GRB040916: Optical observations
  66. GRB/XRF040912,optical observations
  67. GRB 040912, BVRI observations
  68. Optical observations of field of GRB040912
  69. HETE 3557: Optical observations
  70. GRB040825B, BVRcIc field photometry
  71. GRB040825A, BVRcIc field photometry
  72. GCN GRB OBSERBATION REPORT
  73. GRB 040825A,optical observations
  74. Increase of SGR 1806-20 activity
  75. GRB040825A: optical observations
  76. GRB040825B: optical observations
  77. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  78. GRB 040825A: Optical observations.
  79. MASTER: GRB040825b optical observation
  80. GRB040825B: Correction to GCN 2657
  81. GRB 040812: Second epoch CXO Observations
  82. GRB040823,optical observation
  83. Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
  84. CXO observation of GRB 040812
  85. Ongoing activity of SGR 1806-20
  86. GRB040709 J,H-band observations
  87. GRB040706:observation at University of Miyazaki
  88. GRB 040606: Optical observations
  89. MASTER: HETE Alert 3274 optical observation
  90. Activivty of SGR 1806-20
  91. GRB 040511: Optical limit
  92. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  93. GRB040511: Optical Observations
  94. GRB040511: Optical Observations
  95. GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
  96. GRB040422: optical observations at CrAO
  97. GRB 040423 (=H3175): A Long GRB Localized by HETE
  98. GRB040422, optical observations at Loiano
  99. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  100. GRB 040422,optical observation

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