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"

35953 results found.

  1. GRB 021004: Optical observations at RIKEN
  2. GRB 021004 radio observation
  3. GRB 021004: Optical Observations
  4. GRB021004: continued fading
  5. GRB 021004: Optical Photometry at 1.5 Days
  6. GRB021004, Optical Observations
  7. GRB021004, BVRcIc field photometry
  8. GRB 021004: Optical observations
  9. GRB 021004: optical counterpart
  10. GRB 021004, optical observations
  11. GRB021004: Optical Spectroscopy
  12. GRB 021004: Optical Observations
  13. GRB 021004, SPM optical observations
  14. GRB 021004, optical observations
  15. GRB 021004 radio search
  16. GRB 021004: radio observations
  17. GRB 021004: steepening of the optical decay slope
  18. GRB021004: Upper limits from recent and historical observations
  19. XRF020903, BVRI field photometry
  20. GRB021004: optical observations at Nyrola
  21. GRB021004: Absorption redshift
  22. GRB 021004: Kyoto observation
  23. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  24. GRB021004: Optical Afterglow
  25. GRB 020903: Optical observations at RIKEN
  26. IPN triangulation of GRB020926 (single large error box)
  27. GRB 020903: correction to GCN 1557
  28. XRF 020903: R band observations
  29. Radio Observations of XRF 020903: The Missing Link
  30. IPN triangulation of GRB020926 (two large error boxes)
  31. GRB020924 (ecliptic latitude-only localization)
  32. IPN triangulation of GRB020923 (two error boxes)
  33. IPN annulus for GRB020923
  34. IPN triangulation of GRB020914B
  35. Improved IPN position for GRB020918 (two large error boxes)
  36. IPN annulus for GRB020914B
  37. IPN triangulation of GRB020918 (annulus)
  38. IPN triangulation of GRB020911 (2 large error boxes)
  39. IPN triangulation of GRB020914 - clarification and additional information
  40. IPN triangulation of GRB020914
  41. GRB 020305: HST/STIS observations
  42. Confirmation of IPN error box for GRB020910
  43. IPN triangulation of GRB020910
  44. IPN GCN Circulars now to be issued without restriction
  45. Single IPN error box for GRB020904
  46. XRF 020903: optical observation at Kyoto
  47. GRB020322 : HST/STIS observations
  48. IPN triangulation of GRB020904
  49. IPN detection of a burst from SGR1900+14
  50. INTEGRAL GRBs added to GCN
  51. GRB020813: High-resolution optical spectroscopy
  52. GRB 020812: optical observation at Kyoto University
  53. Second epoch K band imaging of GRB 020819
  54. GRB020813, Baade 6.5m data now available
  55. GRB 020813 : HST observations
  56. Confirming no variability for GRB02081
  57. GRB020819 : Optical observations at KISO
  58. GRB 020812: early time optical observation at Ouda Station
  59. GRB020813: VRI Decay Slopes
  60. GRB 020819 : OT candidate - confirmation of non variability
  61. GRB 020819: Optical observations
  62. K band observation of GRB 020819
  63. GRB020819: optical observations
  64. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  65. IPN triangulation of GRB020819 (HETE 2275)
  66. GRB020813, UBVRI field calibration
  67. GRB 020813: addendum to GCN 1498
  68. GRB020813: optical observations at Bisei
  69. GRB020813: V-band decay slope
  70. Polarimetry of GRB020813: evidence for variability
  71. GRB020813 IRAM millimeter observations
  72. GRB020812: optical observations
  73. GRB 020812: optical observation at Bisei
  74. GRB020813: optical observations; possible host galaxy
  75. GRB 020813, radio detection
  76. GRB 020812 : optical afterglow candidate
  77. Millimeter observation of GRB 020813
  78. GRB020812: optical observations
  79. GRB 020813 : KISO multiband optical observations
  80. IPN error box for GRB020813
  81. IPN triangulation of GRB020813
  82. GRB020812: possible afterglow candidate
  83. Early Time Limits for GRB020813
  84. GRB020812: possible afterglow candidate
  85. GRB020813, astrometric position
  86. Spectropolarimetry of GRB 020813
  87. GRB 020813 Afterglow Observations; Possible break
  88. GRB 020813: Absorption redshift
  89. GRB 020813 multiband optical observations
  90. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  91. GRB 020812 optical observation
  92. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  93. GRB 020715, optical observations
  94. GRB 020714, optical observations
  95. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  96. HST Imaging of the Host of GRB 011121
  97. GRB020801, optical afterglow candidate
  98. Further refinement to IPN error box for GRB020531
  99. GRB020331: Late-time Optical Light Curve (re-submission)
  100. GRB020331: Late-time Optical Light Curve

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