Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

11504 results found.

  1. ATCA observations of SGR 1806-20
  2. SGR 1806-20, RHESSI observations of the 041227 giant flare
  3. Third epoch observations of SGR 1806-20 with VLA
  4. Second Epoch VLA observations of SGR 1806-20
  5. Second-epoch VLA observations of SGR 1806-20
  6. SGR1806: Detection of a Sudden Ionospheric Disturbance
  7. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  8. VLA observations of SGR 1806-20
  9. SGR1806 VLA Observations
  10. VLA observations of SGR 1806-20
  11. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  12. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  13. Detection of the SGR 1806-20 giant outburst back-scattered by the
  14. The giant outburst from SGR 1806-20
  15. IPN localization of giant flare from SGR1806-20
  16. Giant flare from SGR 1806-20 detected by INTEGRAL
  17. NIR Observations of GRB 041219
  18. GRB041226: ROTSE-III Optical Observations
  19. GRB041226: Swift-BAT detection of a burst
  20. GRB041224: ROTSE-III Optical Observations
  21. GRB041224: Swift-BAT detection of a soft burst
  22. GRB 041223: Detection of Optical Transient with LCO40
  23. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  24. GRB041223: ROTSE-III Optical Observations
  25. Very high activity of SGR 1806-20
  26. GRB 041219: WSRT Radio Afterglow Detection
  27. GRB 041219 : optical follow-up observations
  28. GRB041219c: Third Burst in One Day from Swift-BAT
  29. GRB041219: Optical Afterglow Detection
  30. GRB041218: optical observations
  31. GRB041219: P60 Optical Observations
  32. GRB 041219 - A long GRB detected by INTEGRAL
  33. GRB 041218; optical candidate
  34. GRB 041218: Optical observations
  35. GRB 041218 - A long GRB detected by integral
  36. GRB041217: The First GRB Located On-Board Swift
  37. GRB041211: Continued P60 Observations
  38. GRB 041211: Infrared Observations
  39. GRB 041211: KAIT observations
  40. GRB 041211: Optical follow-up in East Asian region
  41. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  42. GRB041015: Near-Infrared observations
  43. GRB 041006: GETS Optical Afterglow Observation
  44. Summary of the recent bursts from SGR 1806-20
  45. GRB041015, optical observation in CrAO
  46. IBAS GRB Alert # 2034
  47. Bright bursts from SGR1806-20
  48. GRB041016: MASTER: Optical observations
  49. GRB 041015 R band observations
  50. GRB041015: MASTER: Optical observations
  51. GRB041006: Fading X-ray Afterglow Observed with Chandra
  52. GRB 041015: Optical limit at Osaka University
  53. GRB 041015 - A long GRB detected by INTEGRAL
  54. GRB041006, optical observation in CrAO
  55. Search for SN light in XRF 040912 with MEGACAM
  56. GRB 041006 : optical follow-up observation at Lulin Observatory
  57. ROTSE-IIIa Observations of GRB 041006
  58. GRB 041006: Optical decay
  59. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  60. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  61. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  62. SGR 1806-20 still active
  63. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  64. GRB040924,optical observation
  65. GRB040924, RTT150 optical observation
  66. GRB040924 : Optical candidate observations at Lulin observatory
  67. GRB 040924: RTT150 optical observations
  68. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  69. XRF040916: continuing decay of OT
  70. GRB040912(=H3557): Candidate Optical Afterglow
  71. GRB040916 optical limits 17 min after GRB
  72. XRF 040912, identification of CXO sources
  73. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  74. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  75. GRB 040912: Optical Observations
  76. An intense burst from SGR1806-20
  77. GRB040912 : Kiso Optical follow-up observation
  78. HETE 3557: Optical observations
  79. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  80. GRB040903 - A XRF?
  81. GRB040827: analysis of the XMM-Newton observation
  82. Very bright burst detected from SGR 1806-20
  83. Possible GRB 040903 - further analysis
  84. GRB 040827 : peak flux
  85. Increase of SGR 1806-20 activity
  86. GRB 040812: Optical counterparts of CXO sources
  87. Bursting activity from SGR 1806-20 detected with IBAS
  88. Konus-Wind observation of GRB040810 (=H3489)
  89. GRB 040812: a long GRB detected by INTEGRAL
  90. GRB 040730: Optical observations
  91. GRB 040730: a long GRB detected with INTEGRAL
  92. Ongoing activity of SGR 1806-20
  93. XRF 040701 - optical observations of the decaying Chandra source
  94. XRF040701: Second-Epoch Chandra Observations
  95. Cancellation of IBAS/INTEGRAL GRB alerts
  96. XRF040701: VLA Observations
  97. XRF040701: First-Epoch Chandra Observations
  98. GRB040709 J,H-band observations
  99. GRB 040624: optical observations
  100. GRB 040624: R-band observations

Advanced

Download all Circulars as a .tar.gz archive:
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