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"

26420 results found.

  1. GRB040827: analysis of the XMM-Newton observation
  2. GRB040903, REM near-IR observation
  3. Very bright burst detected from SGR 1806-20
  4. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  5. Possible GRB 040903 - further analysis
  6. GRB 040827 - Radio Observations
  7. XMM-Newton Images of GRB 040827
  8. GRB 040827: optical and NIR observations at the VLT
  9. GRB 040827: UKIRT - 2nd epoch K-band imaging
  10. GRB 040827: 2nd epoch of Magellan K-band imaging
  11. GRB 040827: K imaging - no evidence of variability
  12. GRB 040827: Detection of NIR afterglow
  13. GRB040827 XMM-Newton observation
  14. GRB040825A: optical limit before GRB
  15. GRB 040825B: Optical observations
  16. GRB 040827 : Planned XMM-Newton observation
  17. GRB040825B, BVRcIc field photometry
  18. GRB040825A, BVRcIc field photometry
  19. GCN GRB OBSERBATION REPORT
  20. GRB 040825A,optical observations
  21. GRB040825A: optical observations
  22. GRB040825B: optical observations
  23. MASTER: GRB040825b optical observation
  24. GRB 040825: Optical observations
  25. XRF040812: possible afterglow second Chandra observation
  26. GRB 040812: Second epoch CXO Observations
  27. GRB040823,optical observation
  28. XRF040812: GMRT observations
  29. XRF 040812: optical observation at VLT
  30. GRB 040812: Optical counterparts of CXO sources
  31. XRF040812: possible afterglow
  32. CXO observation of GRB 040812
  33. GRB 040812: radio observations
  34. GRB040812, optical/IR observations
  35. GRB 040812: a long GRB detected by INTEGRAL
  36. XRF040701: Optical Observations at ESO
  37. GRB 040730, infrared observations
  38. GRB 040730: a long GRB detected with INTEGRAL
  39. Ongoing activity of SGR 1806-20
  40. GRB040624: optical monitoring at TNG
  41. XRF 040701 - optical observations of the decaying Chandra source
  42. XRF040701: Second-Epoch Chandra Observations
  43. XRF040701: VLA Observations
  44. XRF040701: First-Epoch Chandra Observations
  45. GRB040624, optical observations
  46. GRB040706:observation at University of Miyazaki
  47. Optical Observations of GRB040624
  48. GRB 040624: optical observations at TNG and VLT
  49. MASTER: GRB 040624 optical observation after 0,48d
  50. GRB 040624, optical observations
  51. GRB 040624 - A long GRB detected with INTEGRAL
  52. GRB 030329: Rebrightening of hyperluminal ejecta.
  53. IPN Summary of SGR1806-20 Activity in 2004
  54. SGR 1806-20: no IR variability of the proposed counterparts
  55. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  56. SGR 1806-20, potential NIR counterpart
  57. GRB 040606: Optical observations
  58. MASTER: HETE Alert 3274 optical observation
  59. Activivty of SGR 1806-20
  60. GRB 040511, very fast decay?
  61. GRB 030324: Detection and Color of Host Galaxy
  62. GRB 040511: NIR observations with REM
  63. GRB040511: Candidate optical/NIR afterglow
  64. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  65. GRB 040511: Second Epoch Optical Observations
  66. GRB 040511: Optical observations
  67. GRB 040511: Optical Observations
  68. GRB040511: Optical Observations
  69. GRB040511: Optical Observations
  70. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  71. GRB 040423 (=H3175): A Long GRB Localized by HETE
  72. GRB040422 : I-band follow-up observation at Lulin Observatory
  73. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  74. GRB040422, BVRcIc field calibration
  75. GRB 040422,optical observation
  76. GRB 040422: a long GRB detected with INTEGRAL
  77. GRB 040403, deep optical observations
  78. MASTER: HETE Alert 3163, 3167 technical optical observation
  79. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  80. GRB 040403: Optical observations
  81. GRB 040403: a long GRB detected with INTEGRAL
  82. GRB040323: NIR Observations and Variable Object
  83. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  84. GRB 040323, a dark GRB ?
  85. GRB 040323: a long GRB detected with INTEGRAL
  86. GRB040223: Deep NIR NTT data re-analysis
  87. GRB 040223: XMM-Newton results
  88. GRB040223, improved XMM position
  89. GRB 031203, possible supernova
  90. MASTER: RXTE GRB040308 optical observation
  91. IBAS results on a burst from SGR1806-20
  92. INTEGRAL detection of activity from SGR1806-20
  93. RXTE GRB040229 optical observation: no candidate
  94. GRB 040228 Optical observations
  95. GRB040228 : KISO optical follow-up observation
  96. GRB 040223: Deep NIR NTT observations
  97. GRB 040223 : Optical observation (non-detection)
  98. XMM-Newton Images of GRB 040223
  99. GRB 040223, VLA observations
  100. GRB 040223: REM IJK 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