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"

28055 results found.

  1. GRB041006,optical observation
  2. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  3. GRB041006: Fading of optical afterglow candidate
  4. GRB 041006: Optical afterglow candidate
  5. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  6. XRF 020903: Observations of the Host Galaxy
  7. radio observations, GRB 040924
  8. GRB040929,optical observation
  9. GRB040924,optical observation
  10. GRB040924,optical observation
  11. GRB 040924: detection of possible host galaxy by Subaru
  12. GRB040924: KAIT observations
  13. GRB040924 : Optical candidate observations at Lulin observatory
  14. GRB040924 : Optical candidate observations at Lulin observatory
  15. GRB 040924: Subaru NIR observation
  16. XRF 040912: Radio Observations
  17. XRF 040916: Radio Observations
  18. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  19. XRF040916: continuing decay of OT
  20. TAROT Observations of GRB 040916 (HETE #3558)
  21. GRB040912(=H3557): Candidate Optical Afterglow
  22. XRF040916, optical observations
  23. XRF 040912, identification of CXO sources
  24. XRF040912, BVRcIc field calibration
  25. XRF040916, BVRcIc field calibration
  26. GRB040916: Archival optical observations
  27. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  28. GRB040916: Optical observations
  29. GRB040912 (= H3557): Chandra Observations Scheduled
  30. GRB 040912: Optical Observations
  31. GRB/XRF040912,optical observations
  32. GRB 040912, BVRI observations
  33. Optical observations of field of GRB040912
  34. HETE 3557: Optical observations
  35. GRB040903 - A XRF?
  36. GRB040827: analysis of the XMM-Newton observation
  37. GRB040903, REM near-IR observation
  38. Very bright burst detected from SGR 1806-20
  39. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  40. Possible GRB 040903 - further analysis
  41. GRB 040827 - Radio Observations
  42. XMM-Newton Images of GRB 040827
  43. GRB 040827: optical and NIR observations at the VLT
  44. GRB 040827: UKIRT - 2nd epoch K-band imaging
  45. GRB 040827: 2nd epoch of Magellan K-band imaging
  46. GRB 040827: K imaging - no evidence of variability
  47. GRB 040827: Detection of NIR afterglow
  48. GRB040827 XMM-Newton observation
  49. GRB040825A: optical limit before GRB
  50. GRB 040825B: Optical observations
  51. GRB 040827 : Planned XMM-Newton observation
  52. GRB040825B, BVRcIc field photometry
  53. GRB040825A, BVRcIc field photometry
  54. GCN GRB OBSERBATION REPORT
  55. GRB 040825A,optical observations
  56. GRB040825A: optical observations
  57. GRB040825B: optical observations
  58. MASTER: GRB040825b optical observation
  59. GRB 040825: Optical observations
  60. XRF040812: possible afterglow second Chandra observation
  61. GRB 040812: Second epoch CXO Observations
  62. GRB040823,optical observation
  63. XRF040812: GMRT observations
  64. XRF 040812: optical observation at VLT
  65. GRB 040812: Optical counterparts of CXO sources
  66. XRF040812: possible afterglow
  67. CXO observation of GRB 040812
  68. GRB 040812: radio observations
  69. GRB040812, optical/IR observations
  70. GRB 040812: a long GRB detected by INTEGRAL
  71. XRF040701: Optical Observations at ESO
  72. GRB 040730, infrared observations
  73. GRB 040730: a long GRB detected with INTEGRAL
  74. Ongoing activity of SGR 1806-20
  75. GRB040624: optical monitoring at TNG
  76. XRF 040701 - optical observations of the decaying Chandra source
  77. XRF040701: Second-Epoch Chandra Observations
  78. XRF040701: VLA Observations
  79. XRF040701: First-Epoch Chandra Observations
  80. GRB040624, optical observations
  81. GRB040706:observation at University of Miyazaki
  82. Optical Observations of GRB040624
  83. GRB 040624: optical observations at TNG and VLT
  84. MASTER: GRB 040624 optical observation after 0,48d
  85. GRB 040624, optical observations
  86. GRB 040624 - A long GRB detected with INTEGRAL
  87. GRB 030329: Rebrightening of hyperluminal ejecta.
  88. IPN Summary of SGR1806-20 Activity in 2004
  89. SGR 1806-20: no IR variability of the proposed counterparts
  90. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  91. SGR 1806-20, potential NIR counterpart
  92. GRB 040606: Optical observations
  93. MASTER: HETE Alert 3274 optical observation
  94. Activivty of SGR 1806-20
  95. GRB 040511, very fast decay?
  96. GRB 030324: Detection and Color of Host Galaxy
  97. GRB 040511: NIR observations with REM
  98. GRB040511: Candidate optical/NIR afterglow
  99. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  100. GRB 040511: Second Epoch Optical Observations

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