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"

42588 results found.

  1. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  2. GRB 030226 simultaneous optical observations
  3. GRB 030226, optical observations
  4. GRB030226: Optical decay index
  5. GRB 030226 Optical Spectra and R,I,z' Imaging
  6. GRB 030226, optical observations
  7. GRB 030226: Optical afterglow
  8. GRB030226: Candidate optical afterglow
  9. GRB 030217: Optical Observations at 4, 5, and 6 Days
  10. IPN triangulation of GRB030223 (annulus)
  11. IPN triangulation of GRB030220 (annulus)
  12. GRB: Non-Referencing of GCN Circulars.
  13. IPN triangulation of GRB030218 (annulus)
  14. GRB030217: optical observations
  15. IPN triangulation of GRB030217 (small error box)
  16. IPN triangulation of GRB030215C (annulus)
  17. IPN triangulation of GRB030217 (annulus)
  18. IPN triangulation of GRB030216 (annulus)
  19. IPN triangulation of GRB030215A and GRB030215B (annuli)
  20. GRB030115, WSRT radio observations - correction to GCN 1864
  21. GRB 030131: marginal optical detection
  22. GCN/INTEGRAL Mistake Fixed
  23. GRB030115, WSRT radio observations
  24. IPN triangulation of GRB030206 (annulus)
  25. IPN triangulation of GRB030208 (annulus)
  26. GRB 030204: Optical Observations
  27. GRB030204 field photometry
  28. GRB020819: Kiso R and I band observations
  29. GRB030131: Candidate Optical Afterglow
  30. GRB 030115: Optical Observations
  31. GRB 030204, optical observations
  32. IPN triangulation of GRB030204 (small error box)
  33. IPN triangulation of GRB030202 (annulus)
  34. GRB030131: Kiso optical limit for corrected position
  35. GRB030131: Optical limits for corrected position
  36. GRB 030131: afterglow candidate
  37. GRB 030115, late-time optical observations
  38. GRB030131: corrected INTEGRAL position
  39. Type Ic SN2003L (SN/GRB?), optical spectrum
  40. GRB030131: Kiso Observations
  41. GRB 020819: Host galaxy at Radio Position
  42. IPN triangulation of GRB030131 - CORRECTION
  43. GRB 020819: afterglow candidate
  44. IPN triangulation of GRB030131
  45. GRB030131: Optical limit
  46. GRB 030131 optical observations
  47. GRB030131: refined position
  48. GRB 030131 optical observations
  49. A long GRB detected by INTEGRAL
  50. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  51. Type Ic SN2003L (SN/GRB?) Radio Observations
  52. IPN triangulation of GRB030127 (annulus)
  53. GRB030115 submm upper limit
  54. IPN triangulation of GRB030119 (two large error boxes)
  55. GRB 030115: Further IR observations with IRSF/SIRIUS
  56. IPN triangulation of GRB030117 (two large error boxes)
  57. Publicizing GRB Discoveries - A Message from NASA HQ
  58. GRB 030115: Radio detection of IR candidate
  59. GRB 030115, simultaneous observations by BOOTES-1
  60. IPN triangulation of GRB030115C (large error box)
  61. GRB030115: R-band counterpart of IR candidate
  62. GRB030115, afterglow candidate
  63. GRB 021211: R-band observations at late-time
  64. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  65. IPN triangulation of GRB030115B (small error box)
  66. GRB 030115 : Possible IR counterpart
  67. GRB 030115: Radio Observations
  68. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  69. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  70. IPN triangulation of GRB030115B (annulus)
  71. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  72. Distribution of INTEGRAL SPI-ACS triggers
  73. GRB030115: R-band observations at Asiago
  74. GRB030115: TAROT optical observations
  75. GRB 021211: VLT spectrum
  76. GRB 030115, no optical candidate
  77. GRB 030115, optical observations
  78. GRB 030115, optical candidate
  79. Possible GRB030113 seen by SPI ACS
  80. Probable GRB030112B seen by SPI ACS
  81. Probable GRB030112 seen by SPI ACS
  82. Information about where HETE will be pointing
  83. Possible GRB030111 seen by SPI ACS
  84. Possible GRB030110b seen by SPI ACS
  85. Possible GRB 030110 seen by SPI ACS
  86. IPN triangulation of GRB030109 (annulus)
  87. IPN triangulation of GRB030105 (large error box)
  88. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  89. Possible GRB 20030109 seen by SPI ACS
  90. IPN triangulation of GRB030102B (portion of annulus)
  91. IPN triangulation of GRB030102A (large error box)
  92. Coronas-F -Wind triangulation of GRB030102
  93. Possible GRB20030107 seen by SPI-ACS
  94. Possible GRB 20030105 seen by SPI ACS
  95. IPN triangulation of GRB030102 (annulus)
  96. GRB on 20030102 seen by SPI-ACS
  97. VLT spectroscopy of the probable host of GRB 021211
  98. GRB on 20030101 seen by SPI-ACS
  99. IPN triangulation of GRB030101 (two large error boxes)
  100. GRB021226

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