Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

19505 results found.

  1. GRB041015: Near-Infrared observations
  2. GRB 040924: Afterglow Color
  3. GRB 041006: GETS Optical Afterglow Observation
  4. Summary of the recent bursts from SGR 1806-20
  5. GRB 041006: Optical Observations
  6. GRB041006, late-time optical photometry
  7. GRB041006: RTT150 Optical Observations
  8. Bright bursts from SGR1806-20
  9. GRB 041016: BOOTES-2 simultaneous observation
  10. GRB041006: RTT150 Optical Observations
  11. GRB041016,optical observation
  12. GRB 041016: Optical limits
  13. GRB 041016:Optical limit during first minute
  14. GRB 041016: Optical limit
  15. GRB 041015 R band observations
  16. GRB040924, BVRcIc field calibration
  17. GRB041015,optical observation
  18. GRB041006: Fading X-ray Afterglow Observed with Chandra
  19. GRB041006: Optical observations and Potential host galaxy
  20. GRB041006, BVRcIc field calibration
  21. GRB 041006: SARA afterglow observations
  22. GRB041006, optical observation in CrAO
  23. Search for SN light in XRF 040912 with MEGACAM
  24. GRB 041006: BR observations with VATT
  25. GRB041006 (= H3570): Chandra Observations In Progress
  26. GRB041006, optical I observation
  27. ROTSE-IIIa Observations of GRB 041006
  28. GRB041006: MASTER optical observations
  29. GRB041006,optical observation
  30. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  31. GRB041006: Fading of optical afterglow candidate
  32. GRB 041006: Optical afterglow candidate
  33. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  34. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  35. radio observations, GRB 040924
  36. GRB040929,optical observation
  37. GRB040924,optical observation
  38. GRB040924,optical observation
  39. GRB040924: KAIT observations
  40. GRB 040924: Subaru NIR observation
  41. GRB 040924, optical follow-up
  42. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  43. XRF040916: continuing decay of OT
  44. TAROT Observations of GRB 040916 (HETE #3558)
  45. GRB040912(=H3557): Candidate Optical Afterglow
  46. XRF040916, optical observations
  47. XRF 040912, identification of CXO sources
  48. XRF 040912 (=H3557): Spectral and Temporal Properties
  49. XRF040912, BVRcIc field calibration
  50. XRF040916, BVRcIc field calibration
  51. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  52. GRB040916: Optical observations
  53. GRB 040912: Optical Observations
  54. GRB/XRF040912,optical observations
  55. GRB 040912, BVRI observations
  56. An intense burst from SGR1806-20
  57. GRB040912 : Kiso Optical follow-up observation
  58. Optical observations of field of GRB040912
  59. HETE 3557: Optical observations
  60. GRB040903 - A XRF?
  61. GRB040827: analysis of the XMM-Newton observation
  62. GRB040903, REM near-IR observation
  63. Very bright burst detected from SGR 1806-20
  64. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  65. GRB 040827 - Radio Observations
  66. XMM-Newton Images of GRB 040827
  67. GRB 040827: optical and NIR observations at the VLT
  68. GRB 040827: RTT150 optical observations
  69. GRB040827 XMM-Newton observation
  70. MASTER: GRB040827 possible OT
  71. GRB 040825B: Optical observations
  72. GRB 040827 : Planned XMM-Newton observation
  73. GRB 040827 - Refined position
  74. GRB040825B, BVRcIc field photometry
  75. GRB040825A, BVRcIc field photometry
  76. GCN GRB OBSERBATION REPORT
  77. GRB 040825A,optical observations
  78. Increase of SGR 1806-20 activity
  79. GRB040825A: optical observations
  80. GRB040825B: optical observations
  81. GRB 040812: Second epoch CXO Observations
  82. GRB040823,optical observation
  83. XRF040812: GMRT observations
  84. XRF 040812: optical observation at VLT
  85. GRB 040812: Optical counterparts of CXO sources
  86. CXO observation of GRB 040812
  87. GRB040812, optical/IR observations
  88. Konus-Wind observation of GRB040810 (=H3489)
  89. XRF040701: Optical Observations at ESO
  90. GRB 040730, infrared observations
  91. Ongoing activity of SGR 1806-20
  92. GRB040624: optical monitoring at TNG
  93. XRF 040701 - optical observations of the decaying Chandra source
  94. XRF040701: Second-Epoch Chandra Observations
  95. XRF040701: VLA Observations
  96. XRF040701: First-Epoch Chandra Observations
  97. GRB040624, optical observations
  98. GRB040706:observation at University of Miyazaki
  99. Optical Observations of GRB040624
  100. GRB 040624: optical observations at TNG and VLT

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