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"

45444 results found.

  1. GRB 041006: Radio Observations
  2. GRB041006, further submilllimetre observations
  3. GRB 041006 : optical follow-up observation at Lulin Observatory
  4. GRB 041006 : Optical follow-up observation at TAROT
  5. GRB041006: Optical photometry and spectroscopy at TNG
  6. GRB 041006: presice astrometry
  7. GRB041006 (= H3570): Chandra Observations In Progress
  8. GRB 041006 : optical observation at Bisei
  9. GRB041006, optical I observation
  10. GRB041006 (=HETE3570): optical observations
  11. ROTSE-IIIa Observations of GRB 041006
  12. GRB041006, optical observation
  13. GRB041006, submillimetre observations
  14. GRB041006: MASTER optical observations
  15. GRB041006,optical observation
  16. GRB 041006: Optical decay
  17. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  18. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  19. GRB041006: Fading of optical afterglow candidate
  20. GRB 041006: Finding chart
  21. GRB 041006: Optical afterglow candidate
  22. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  23. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  24. XRF 020903: Observations of the Host Galaxy (authors)
  25. XRF 020903: Observations of the Host Galaxy
  26. GRB 040924: Second Epoch WSRT Radio Observations
  27. radio observations, GRB 040924
  28. IBAS Alert 1991. Not a real GRB
  29. GRB040929,optical observation
  30. GRB040929: MASTER optical observations
  31. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  32. GRB040924,optical observation
  33. GRB040924, RTT150 optical observation
  34. GRB040924,optical observation
  35. GRB 040924: detection of possible host galaxy by Subaru
  36. GRB040924, RTT150 optical observation
  37. GRB040924: KAIT observations
  38. GRB040924: Afterglow magnitude at t=17.5hr
  39. GRB 040924: WSRT Radio Observations
  40. GRB 040924: NIR finding chart
  41. GRB040924 : Optical candidate observations at Lulin observatory
  42. GRB040924 : Optical candidate observations at Lulin observatory
  43. GRB 040924: Subaru NIR observation
  44. GRB040924: Optical afterglow properties
  45. GRB 040924: RTT150 optical observations
  46. GRB 040924, optical follow-up
  47. GRB040924: MASTER: OT decay
  48. GRB040924: MASTER Optical observations
  49. IPN triangulation of GRB040924 (H3564)
  50. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  51. GRB040924 (H3564): Optical afterglow candidate
  52. XRF 040912: Radio Observations
  53. XRF 040916: Radio Observations
  54. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  55. XRF040916: continuing decay of OT
  56. TAROT Observations of GRB 040916 (HETE #3558)
  57. GRB040912(=H3557): Candidate Optical Afterglow
  58. XRF040916, optical observations
  59. XRF040916: Optical Transient Candidate by Subaru
  60. GRB040916 optical limits 17 min after GRB
  61. XRF 040912, identification of CXO sources
  62. XRF 040912 (=H3557): Spectral and Temporal Properties
  63. XRF040916, Ic observations
  64. XRF040916: optical follow-up observations
  65. XRF040912, BVRcIc field calibration
  66. XRF040916, BVRcIc field calibration
  67. GRB040916: Archival optical observations
  68. XRF 040916, optical follow-up
  69. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  70. GRB040916: Optical observations
  71. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  72. GRB040916 (= H3558): Improved Localization from HETE WXM
  73. GRB040916 (= H3558): A Long XRF Localized by HETE
  74. GRB040912 (= H3557): Chandra Observations Scheduled
  75. GRB 040912: Optical Observations
  76. GRB/XRF040912,optical observations
  77. GRB 040912, BVRI observations
  78. Optical observations of GRB/XRF 040912 = HETE 3557
  79. An intense burst from SGR1806-20
  80. GRB040912 : Kiso Optical follow-up observation
  81. IBAS GRB Alerts 1978-1980
  82. Optical observations of field of GRB040912
  83. HETE 3557: Optical observations
  84. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  85. GRB 040827: XMM-Newton data
  86. GRB040903 - A XRF?
  87. GRB040827: analysis of the XMM-Newton observation
  88. GRB040903, REM near-IR observation
  89. GRB 040903 - INTEGRAL data analysis
  90. IBAS Alert 1974. Not a real GRB
  91. Very bright burst detected from SGR 1806-20
  92. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  93. Possible GRB 040903 - further analysis
  94. Possible GRB 040903 detected with INTEGRAL
  95. GRB 040827 - Radio Observations
  96. XMM-Newton Images of GRB 040827
  97. GRB040825A: Optical observations
  98. GRB040825A: Optical observations
  99. GRB 040827: optical and NIR observations at the VLT
  100. GRB 040827: UKIRT - 2nd epoch K-band imaging

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