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"

28057 results found.

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

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