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"

45428 results found.

  1. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  2. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  3. GRB041006: Fading of optical afterglow candidate
  4. GRB 041006: Finding chart
  5. GRB 041006: Optical afterglow candidate
  6. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  7. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  8. XRF 020903: Observations of the Host Galaxy (authors)
  9. XRF 020903: Observations of the Host Galaxy
  10. GRB 040924: Second Epoch WSRT Radio Observations
  11. radio observations, GRB 040924
  12. IBAS Alert 1991. Not a real GRB
  13. GRB040929,optical observation
  14. GRB040929: MASTER optical observations
  15. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  16. GRB040924,optical observation
  17. GRB040924, RTT150 optical observation
  18. GRB040924,optical observation
  19. GRB 040924: detection of possible host galaxy by Subaru
  20. GRB040924, RTT150 optical observation
  21. GRB040924: KAIT observations
  22. GRB040924: Afterglow magnitude at t=17.5hr
  23. GRB 040924: WSRT Radio Observations
  24. GRB 040924: NIR finding chart
  25. GRB040924 : Optical candidate observations at Lulin observatory
  26. GRB040924 : Optical candidate observations at Lulin observatory
  27. GRB 040924: Subaru NIR observation
  28. GRB040924: Optical afterglow properties
  29. GRB 040924: RTT150 optical observations
  30. GRB 040924, optical follow-up
  31. GRB040924: MASTER: OT decay
  32. GRB040924: MASTER Optical observations
  33. IPN triangulation of GRB040924 (H3564)
  34. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  35. GRB040924 (H3564): Optical afterglow candidate
  36. XRF 040912: Radio Observations
  37. XRF 040916: Radio Observations
  38. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  39. XRF040916: continuing decay of OT
  40. TAROT Observations of GRB 040916 (HETE #3558)
  41. GRB040912(=H3557): Candidate Optical Afterglow
  42. XRF040916, optical observations
  43. XRF040916: Optical Transient Candidate by Subaru
  44. GRB040916 optical limits 17 min after GRB
  45. XRF 040912, identification of CXO sources
  46. XRF 040912 (=H3557): Spectral and Temporal Properties
  47. XRF040916, Ic observations
  48. XRF040916: optical follow-up observations
  49. XRF040912, BVRcIc field calibration
  50. XRF040916, BVRcIc field calibration
  51. GRB040916: Archival optical observations
  52. XRF 040916, optical follow-up
  53. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  54. GRB040916: Optical observations
  55. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  56. GRB040916 (= H3558): Improved Localization from HETE WXM
  57. GRB040916 (= H3558): A Long XRF Localized by HETE
  58. GRB040912 (= H3557): Chandra Observations Scheduled
  59. GRB 040912: Optical Observations
  60. GRB/XRF040912,optical observations
  61. GRB 040912, BVRI observations
  62. Optical observations of GRB/XRF 040912 = HETE 3557
  63. An intense burst from SGR1806-20
  64. GRB040912 : Kiso Optical follow-up observation
  65. IBAS GRB Alerts 1978-1980
  66. Optical observations of field of GRB040912
  67. HETE 3557: Optical observations
  68. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  69. GRB 040827: XMM-Newton data
  70. GRB040903 - A XRF?
  71. GRB040827: analysis of the XMM-Newton observation
  72. GRB040903, REM near-IR observation
  73. GRB 040903 - INTEGRAL data analysis
  74. IBAS Alert 1974. Not a real GRB
  75. Very bright burst detected from SGR 1806-20
  76. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  77. Possible GRB 040903 - further analysis
  78. Possible GRB 040903 detected with INTEGRAL
  79. GRB 040827 - Radio Observations
  80. XMM-Newton Images of GRB 040827
  81. GRB040825A: Optical observations
  82. GRB040825A: Optical observations
  83. GRB 040827: optical and NIR observations at the VLT
  84. GRB 040827: UKIRT - 2nd epoch K-band imaging
  85. GRB 040827: 2nd epoch of Magellan K-band imaging
  86. GRB 040827: K imaging - no evidence of variability
  87. GRB 040827: Detection of NIR afterglow
  88. GRB 040827: Possible detection of optical afterglow
  89. GRB 040827: RTT150 optical observations
  90. GRB040827 XMM-Newton observation
  91. GRB040825A: optical limit before GRB
  92. MASTER: GRB040827 possible OT
  93. GRB 040825B: Optical observations
  94. GRB040827 optical observations
  95. GRB 040827 : Planned XMM-Newton observation
  96. GRB 040827 - Refined position
  97. GRB 040827 - A long GRB detected by INTEGRAL
  98. GRB040825B, BVRcIc field photometry
  99. GRB040825A, BVRcIc field photometry
  100. GCN GRB OBSERBATION REPORT

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