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"

28038 results found.

  1. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  2. XRF040916: continuing decay of OT
  3. TAROT Observations of GRB 040916 (HETE #3558)
  4. GRB040912(=H3557): Candidate Optical Afterglow
  5. XRF040916, optical observations
  6. XRF 040912, identification of CXO sources
  7. XRF040912, BVRcIc field calibration
  8. XRF040916, BVRcIc field calibration
  9. GRB040916: Archival optical observations
  10. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  11. GRB040916: Optical observations
  12. GRB040912 (= H3557): Chandra Observations Scheduled
  13. GRB 040912: Optical Observations
  14. GRB/XRF040912,optical observations
  15. GRB 040912, BVRI observations
  16. Optical observations of field of GRB040912
  17. HETE 3557: Optical observations
  18. GRB040903 - A XRF?
  19. GRB040827: analysis of the XMM-Newton observation
  20. GRB040903, REM near-IR observation
  21. Very bright burst detected from SGR 1806-20
  22. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  23. Possible GRB 040903 - further analysis
  24. GRB 040827 - Radio Observations
  25. XMM-Newton Images of GRB 040827
  26. GRB 040827: optical and NIR observations at the VLT
  27. GRB 040827: UKIRT - 2nd epoch K-band imaging
  28. GRB 040827: 2nd epoch of Magellan K-band imaging
  29. GRB 040827: K imaging - no evidence of variability
  30. GRB 040827: Detection of NIR afterglow
  31. GRB040827 XMM-Newton observation
  32. GRB040825A: optical limit before GRB
  33. GRB 040825B: Optical observations
  34. GRB 040827 : Planned XMM-Newton observation
  35. GRB040825B, BVRcIc field photometry
  36. GRB040825A, BVRcIc field photometry
  37. GCN GRB OBSERBATION REPORT
  38. GRB 040825A,optical observations
  39. GRB040825A: optical observations
  40. GRB040825B: optical observations
  41. MASTER: GRB040825b optical observation
  42. GRB 040825: Optical observations
  43. XRF040812: possible afterglow second Chandra observation
  44. GRB 040812: Second epoch CXO Observations
  45. GRB040823,optical observation
  46. XRF040812: GMRT observations
  47. XRF 040812: optical observation at VLT
  48. GRB 040812: Optical counterparts of CXO sources
  49. XRF040812: possible afterglow
  50. CXO observation of GRB 040812
  51. GRB 040812: radio observations
  52. GRB040812, optical/IR observations
  53. GRB 040812: a long GRB detected by INTEGRAL
  54. XRF040701: Optical Observations at ESO
  55. GRB 040730, infrared observations
  56. GRB 040730: a long GRB detected with INTEGRAL
  57. Ongoing activity of SGR 1806-20
  58. GRB040624: optical monitoring at TNG
  59. XRF 040701 - optical observations of the decaying Chandra source
  60. XRF040701: Second-Epoch Chandra Observations
  61. XRF040701: VLA Observations
  62. XRF040701: First-Epoch Chandra Observations
  63. GRB040624, optical observations
  64. GRB040706:observation at University of Miyazaki
  65. Optical Observations of GRB040624
  66. GRB 040624: optical observations at TNG and VLT
  67. MASTER: GRB 040624 optical observation after 0,48d
  68. GRB 040624, optical observations
  69. GRB 040624 - A long GRB detected with INTEGRAL
  70. GRB 030329: Rebrightening of hyperluminal ejecta.
  71. IPN Summary of SGR1806-20 Activity in 2004
  72. SGR 1806-20: no IR variability of the proposed counterparts
  73. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  74. SGR 1806-20, potential NIR counterpart
  75. GRB 040606: Optical observations
  76. MASTER: HETE Alert 3274 optical observation
  77. Activivty of SGR 1806-20
  78. GRB 040511, very fast decay?
  79. GRB 030324: Detection and Color of Host Galaxy
  80. GRB 040511: NIR observations with REM
  81. GRB040511: Candidate optical/NIR afterglow
  82. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  83. GRB 040511: Second Epoch Optical Observations
  84. GRB 040511: Optical observations
  85. GRB 040511: Optical Observations
  86. GRB040511: Optical Observations
  87. GRB040511: Optical Observations
  88. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  89. GRB 040423 (=H3175): A Long GRB Localized by HETE
  90. GRB040422 : I-band follow-up observation at Lulin Observatory
  91. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  92. GRB040422, BVRcIc field calibration
  93. GRB 040422,optical observation
  94. GRB 040422: a long GRB detected with INTEGRAL
  95. GRB 040403, deep optical observations
  96. MASTER: HETE Alert 3163, 3167 technical optical observation
  97. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  98. GRB 040403: Optical observations
  99. GRB 040403: a long GRB detected with INTEGRAL
  100. GRB040323: NIR Observations and Variable Object

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