Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

42600 results found.

  1. GRB 021004: optical counterpart
  2. GRB 021004, optical observations
  3. GRB021004: Optical Spectroscopy
  4. GRB 021004: Optical Observations
  5. GRB 021004, SPM optical observations
  6. GRB 021004, optical observations
  7. GRB 021004 radio search
  8. GRB 021004: radio observations
  9. GRB 021004: steepening of the optical decay slope
  10. GRB021004: Upper limits from recent and historical observations
  11. XRF020903, BVRI field photometry
  12. GRB021004: optical observations at Nyrola
  13. GRB021004: Absorption redshift
  14. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  15. GRB 021004: Kyoto observation
  16. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  17. GRB021004: Optical Afterglow
  18. XRF020903: TNG and Asiago photometry
  19. GRB 020903: Optical observations at RIKEN
  20. XRF 020903: Correction to GCN 1560
  21. XRF 020903: VRI observations
  22. IPN triangulation of GRB020926 (single large error box)
  23. XRF 020903: R band observations
  24. XRF 020903: Archival Optical Images
  25. Radio Observations of XRF 020903: The Missing Link
  26. XRF 020903: Supernova
  27. IPN triangulation of GRB020926 (two large error boxes)
  28. GRB020924 (ecliptic latitude-only localization)
  29. IPN triangulation of GRB020923 (two error boxes)
  30. IPN annulus for GRB020923
  31. IPN triangulation of GRB020914B
  32. Improved IPN position for GRB020918 (two large error boxes)
  33. IPN annulus for GRB020914B
  34. IPN triangulation of GRB020918 (annulus)
  35. IPN triangulation of GRB020911 (2 large error boxes)
  36. IPN triangulation of GRB020914 - clarification and additional information
  37. IPN triangulation of GRB020914
  38. GRB 020305: HST/STIS observations
  39. Confirmation of IPN error box for GRB020910
  40. IPN triangulation of GRB020910
  41. IPN GCN Circulars now to be issued without restriction
  42. Single IPN error box for GRB020904
  43. XRF 020903: optical observation at Kyoto
  44. GRB020322 : HST/STIS observations
  45. XRF 020903: Optical observations
  46. IPN triangulation of GRB020904
  47. XRF 020903: Optical observations
  48. IPN detection of a burst from SGR1900+14
  49. XRF 020903, optical observations
  50. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  51. INTEGRAL GRBs added to GCN
  52. GRB020813: optical observation
  53. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  54. SGR1900+14 burst localized by HETE
  55. GRB020813: High-resolution optical spectroscopy
  56. GRB020819: optical observations at Bisei
  57. GRB020812: negative optical observations
  58. GRB 020812: optical observation at Kyoto University
  59. Second epoch K band imaging of GRB 020819
  60. GRB020813, Baade 6.5m data now available
  61. GRB 020813 : HST observations
  62. Confirming no variability for GRB02081
  63. GRB020819 : Optical observations at KISO
  64. GRB 020812: early time optical observation at Ouda Station
  65. GRB020813: VRI Decay Slopes
  66. GRB020813: Magellan BVRI Photometry
  67. GRB 020819 : OT candidate - confirmation of non variability
  68. GRB 020819: Optical observations
  69. K band observation of GRB 020819
  70. GRB020819: optical observations
  71. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  72. IPN triangulation of GRB020819 (HETE 2275)
  73. HETE 2275: Optical observations
  74. GRB020813: optical and NIR observations
  75. GRB020813: Fading X-ray Afterglow Observed with Chandra
  76. GRB020813, UBVRI field calibration
  77. GRB 020813: addendum to GCN 1498
  78. GRB020813: optical observations at Bisei
  79. GRB020813: V-band decay slope
  80. GRB020812: NIR observations
  81. Polarimetry of GRB020813: evidence for variability
  82. GRB020813 IRAM millimeter observations
  83. GRB020812: optical observations
  84. GRB020813: High-Resolution Optical Observations
  85. GRB020813(=H2262): Revised Localization with HETE SXC
  86. GRB 020812: optical observation at Bisei
  87. GRB020813: Early Time Magnitude
  88. GRB020813: optical observations; possible host galaxy
  89. GRB 020813, radio detection
  90. GRB 020812 : optical afterglow candidate
  91. GRB020813, optical observations
  92. Millimeter observation of GRB 020813
  93. GRB020812: optical observations
  94. GRB 020813 : KISO multiband optical observations
  95. GRB020813, optical observations
  96. IPN error box for GRB020813
  97. IPN triangulation of GRB020813
  98. GRB020812: possible afterglow candidate
  99. Early Time Limits for GRB020813
  100. GRB020812: possible afterglow candidate

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