Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

26363 results found.

  1. GRB 041006: Radio Observations
  2. GRB 041006 : optical follow-up observation at Lulin Observatory
  3. GRB041006: Optical photometry and spectroscopy at TNG
  4. GRB 041006: presice astrometry
  5. GRB041006, optical I observation
  6. GRB041006 (=HETE3570): optical observations
  7. ROTSE-IIIa Observations of GRB 041006
  8. GRB041006: MASTER optical observations
  9. GRB041006,optical observation
  10. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  11. GRB041006: Fading of optical afterglow candidate
  12. GRB 041006: Optical afterglow candidate
  13. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  14. XRF 020903: Observations of the Host Galaxy
  15. radio observations, GRB 040924
  16. GRB040929,optical observation
  17. GRB040924,optical observation
  18. GRB040924,optical observation
  19. GRB 040924: detection of possible host galaxy by Subaru
  20. GRB040924: KAIT observations
  21. GRB040924 : Optical candidate observations at Lulin observatory
  22. GRB040924 : Optical candidate observations at Lulin observatory
  23. GRB 040924: Subaru NIR observation
  24. XRF 040912: Radio Observations
  25. XRF 040916: Radio Observations
  26. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  27. XRF040916: continuing decay of OT
  28. TAROT Observations of GRB 040916 (HETE #3558)
  29. GRB040912(=H3557): Candidate Optical Afterglow
  30. XRF040916, optical observations
  31. XRF 040912, identification of CXO sources
  32. XRF040912, BVRcIc field calibration
  33. XRF040916, BVRcIc field calibration
  34. GRB040916: Archival optical observations
  35. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  36. GRB040916: Optical observations
  37. GRB040912 (= H3557): Chandra Observations Scheduled
  38. GRB 040912: Optical Observations
  39. GRB/XRF040912,optical observations
  40. GRB 040912, BVRI observations
  41. Optical observations of field of GRB040912
  42. HETE 3557: Optical observations
  43. GRB040903 - A XRF?
  44. GRB040827: analysis of the XMM-Newton observation
  45. GRB040903, REM near-IR observation
  46. Very bright burst detected from SGR 1806-20
  47. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  48. Possible GRB 040903 - further analysis
  49. GRB 040827 - Radio Observations
  50. XMM-Newton Images of GRB 040827
  51. GRB 040827: optical and NIR observations at the VLT
  52. GRB 040827: UKIRT - 2nd epoch K-band imaging
  53. GRB 040827: 2nd epoch of Magellan K-band imaging
  54. GRB 040827: K imaging - no evidence of variability
  55. GRB 040827: Detection of NIR afterglow
  56. GRB040827 XMM-Newton observation
  57. GRB040825A: optical limit before GRB
  58. GRB 040825B: Optical observations
  59. GRB 040827 : Planned XMM-Newton observation
  60. GRB040825B, BVRcIc field photometry
  61. GRB040825A, BVRcIc field photometry
  62. GCN GRB OBSERBATION REPORT
  63. GRB 040825A,optical observations
  64. GRB040825A: optical observations
  65. GRB040825B: optical observations
  66. MASTER: GRB040825b optical observation
  67. GRB 040825: Optical observations
  68. XRF040812: possible afterglow second Chandra observation
  69. GRB 040812: Second epoch CXO Observations
  70. GRB040823,optical observation
  71. XRF040812: GMRT observations
  72. XRF 040812: optical observation at VLT
  73. GRB 040812: Optical counterparts of CXO sources
  74. XRF040812: possible afterglow
  75. CXO observation of GRB 040812
  76. GRB 040812: radio observations
  77. GRB040812, optical/IR observations
  78. GRB 040812: a long GRB detected by INTEGRAL
  79. XRF040701: Optical Observations at ESO
  80. GRB 040730, infrared observations
  81. GRB 040730: a long GRB detected with INTEGRAL
  82. Ongoing activity of SGR 1806-20
  83. GRB040624: optical monitoring at TNG
  84. XRF 040701 - optical observations of the decaying Chandra source
  85. XRF040701: Second-Epoch Chandra Observations
  86. XRF040701: VLA Observations
  87. XRF040701: First-Epoch Chandra Observations
  88. GRB040624, optical observations
  89. GRB040706:observation at University of Miyazaki
  90. Optical Observations of GRB040624
  91. GRB 040624: optical observations at TNG and VLT
  92. MASTER: GRB 040624 optical observation after 0,48d
  93. GRB 040624, optical observations
  94. GRB 040624 - A long GRB detected with INTEGRAL
  95. GRB 030329: Rebrightening of hyperluminal ejecta.
  96. IPN Summary of SGR1806-20 Activity in 2004
  97. SGR 1806-20: no IR variability of the proposed counterparts
  98. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  99. SGR 1806-20, potential NIR counterpart
  100. GRB 040606: Optical observations

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