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"
  1. Possible break in the GRB 030226 light curve
  2. GRB 030226 : Predicted light curve
  3. GRB030226: optical observation
  4. IPN triangulation of GRB030225 (annulus)
  5. GRB 030226: Confirmed decay index
  6. GRB030226: ESI spectroscopy
  7. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  8. GRB 030226 simultaneous optical observations
  9. Two absorption systems in GRB 030226
  10. GRB 030226, optical observations
  11. GRB030226: optical observations and refined redshift
  12. GRB030226: Optical decay index
  13. GRB 030226 Optical Spectra and R,I,z' Imaging
  14. GRB 030226, optical observations
  15. GRB 030226: Optical afterglow
  16. GRB030226: Candidate optical afterglow
  17. GRB 030217: Optical Observations at 4, 5, and 6 Days
  18. IPN triangulation of GRB030223 (annulus)
  19. IPN triangulation of GRB030220 (annulus)
  20. GRB: Non-Referencing of GCN Circulars.
  21. IPN triangulation of GRB030218 (annulus)
  22. GRB030217: optical observations
  23. IPN triangulation of GRB030217 (small error box)
  24. IPN triangulation of GRB030215C (annulus)
  25. IPN triangulation of GRB030217 (annulus)
  26. IPN triangulation of GRB030216 (annulus)
  27. IPN triangulation of GRB030215A and GRB030215B (annuli)
  28. GRB030115, WSRT radio observations - correction to GCN 1864
  29. GRB 030131: marginal optical detection
  30. GCN/INTEGRAL Mistake Fixed
  31. GRB030115, WSRT radio observations
  32. IPN triangulation of GRB030206 (annulus)
  33. IPN triangulation of GRB030208 (annulus)
  34. GRB 030204: Optical Observations
  35. GRB030204 field photometry
  36. GRB020819: Kiso R and I band observations
  37. GRB 030204: Correction to GCN 1856
  38. GRB030131: Candidate Optical Afterglow
  39. GRB 030115: Optical Observations
  40. GRB 030204, optical observations
  41. IPN triangulation of GRB030204 (small error box)
  42. IPN triangulation of GRB030202 (annulus)
  43. GRB 030131, optical observations
  44. GRB030131: Kiso optical limit for corrected position
  45. GRB030131: Optical limits for corrected position
  46. GRB 030131: afterglow candidate
  47. GRB 030115, late-time optical observations
  48. GRB030131: corrected INTEGRAL position
  49. Type Ic SN2003L (SN/GRB?), optical spectrum
  50. GRB030131: Kiso Observations
  51. GRB 020819: Host galaxy at Radio Position
  52. IPN triangulation of GRB030131 - CORRECTION
  53. GRB 020819: afterglow candidate
  54. IPN triangulation of GRB030131
  55. GRB030131: Optical limit
  56. GRB 030131 optical observations
  57. GRB030131: refined position
  58. GRB 030131 optical observations
  59. A long GRB detected by INTEGRAL
  60. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  61. Type Ic SN2003L (SN/GRB?) Radio Observations
  62. IPN triangulation of GRB030127 (annulus)
  63. GRB030115 submm upper limit
  64. IPN triangulation of GRB030119 (two large error boxes)
  65. GRB 030115: Further IR observations with IRSF/SIRIUS
  66. IPN triangulation of GRB030117 (two large error boxes)
  67. Publicizing GRB Discoveries - A Message from NASA HQ
  68. GRB 030115: Radio detection of IR candidate
  69. GRB 030115, simultaneous observations by BOOTES-1
  70. GRB 030115: IR observations with IRSF/SIRIUS
  71. IPN triangulation of GRB030115C (large error box)
  72. GRB030115: R-band counterpart of IR candidate
  73. GRB030115, afterglow candidate
  74. GRB 021211: R-band observations at late-time
  75. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  76. IPN triangulation of GRB030115B (small error box)
  77. GRB 030115 : Possible IR counterpart
  78. GRB 030115: Radio Observations
  79. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  80. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  81. IPN triangulation of GRB030115B (annulus)
  82. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  83. Distribution of INTEGRAL SPI-ACS triggers
  84. GRB030115: R-band observations at Asiago
  85. GRB030115: TAROT optical observations
  86. GRB 021211: VLT spectrum
  87. GRB 030115: APO Optical Observations
  88. GRB 030115, no optical candidate
  89. GRB 030115, optical observations
  90. GRB 030115, optical candidate
  91. Possible GRB030113 seen by SPI ACS
  92. Probable GRB030112B seen by SPI ACS
  93. Probable GRB030112 seen by SPI ACS
  94. Information about where HETE will be pointing
  95. Possible GRB030111 seen by SPI ACS
  96. Possible GRB030110b seen by SPI ACS
  97. Possible GRB 030110 seen by SPI ACS
  98. IPN triangulation of GRB030109 (annulus)
  99. IPN triangulation of GRB030105 (large error box)
  100. IPN triangulation of GRB030102B (refined localization - portion of annulus)

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