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"

42560 results found.

  1. GRB030227:Optical observations
  2. GRB 20030226: Upper limits from recent and historical observations
  3. GRB 030227, possible optical counterpart of XMM-Newton source
  4. GRB030227 - faint tentative OT candidate
  5. GRB 030226, optical observations
  6. XMM-Newton observation of GRB030227
  7. GRB030227: Kiso optical observations
  8. GRB 030227: Kyoto optical observation
  9. GRB 030226, optical light curve
  10. GRB 030226 spectroscopy
  11. Possible break in the GRB 030226 light curve
  12. GRB 030226 : Predicted light curve
  13. GRB030226: optical observation
  14. IPN triangulation of GRB030225 (annulus)
  15. GRB 030226: Confirmed decay index
  16. GRB030226: ESI spectroscopy
  17. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  18. GRB 030226 simultaneous optical observations
  19. GRB 030226, optical observations
  20. GRB030226: Optical decay index
  21. GRB 030226 Optical Spectra and R,I,z' Imaging
  22. GRB 030226, optical observations
  23. GRB 030226: Optical afterglow
  24. GRB030226: Candidate optical afterglow
  25. GRB 030217: Optical Observations at 4, 5, and 6 Days
  26. IPN triangulation of GRB030223 (annulus)
  27. IPN triangulation of GRB030220 (annulus)
  28. GRB: Non-Referencing of GCN Circulars.
  29. IPN triangulation of GRB030218 (annulus)
  30. GRB030217: optical observations
  31. IPN triangulation of GRB030217 (small error box)
  32. IPN triangulation of GRB030215C (annulus)
  33. IPN triangulation of GRB030217 (annulus)
  34. IPN triangulation of GRB030216 (annulus)
  35. IPN triangulation of GRB030215A and GRB030215B (annuli)
  36. GRB030115, WSRT radio observations - correction to GCN 1864
  37. GRB 030131: marginal optical detection
  38. GCN/INTEGRAL Mistake Fixed
  39. GRB030115, WSRT radio observations
  40. IPN triangulation of GRB030206 (annulus)
  41. IPN triangulation of GRB030208 (annulus)
  42. GRB 030204: Optical Observations
  43. GRB030204 field photometry
  44. GRB020819: Kiso R and I band observations
  45. GRB030131: Candidate Optical Afterglow
  46. GRB 030115: Optical Observations
  47. GRB 030204, optical observations
  48. IPN triangulation of GRB030204 (small error box)
  49. IPN triangulation of GRB030202 (annulus)
  50. GRB030131: Optical limits for corrected position
  51. GRB 030131: afterglow candidate
  52. GRB 030115, late-time optical observations
  53. GRB030131: corrected INTEGRAL position
  54. Type Ic SN2003L (SN/GRB?), optical spectrum
  55. GRB030131: Kiso Observations
  56. GRB 020819: Host galaxy at Radio Position
  57. IPN triangulation of GRB030131 - CORRECTION
  58. GRB 020819: afterglow candidate
  59. IPN triangulation of GRB030131
  60. GRB030131: Optical limit
  61. GRB 030131 optical observations
  62. GRB 030131 optical observations
  63. A long GRB detected by INTEGRAL
  64. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  65. Type Ic SN2003L (SN/GRB?) Radio Observations
  66. IPN triangulation of GRB030127 (annulus)
  67. GRB030115 submm upper limit
  68. IPN triangulation of GRB030119 (two large error boxes)
  69. IPN triangulation of GRB030117 (two large error boxes)
  70. Publicizing GRB Discoveries - A Message from NASA HQ
  71. GRB 030115: Radio detection of IR candidate
  72. GRB 030115, simultaneous observations by BOOTES-1
  73. IPN triangulation of GRB030115C (large error box)
  74. GRB030115: R-band counterpart of IR candidate
  75. GRB030115, afterglow candidate
  76. GRB 021211: R-band observations at late-time
  77. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  78. IPN triangulation of GRB030115B (small error box)
  79. GRB 030115 : Possible IR counterpart
  80. GRB 030115: Radio Observations
  81. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  82. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  83. IPN triangulation of GRB030115B (annulus)
  84. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  85. Distribution of INTEGRAL SPI-ACS triggers
  86. GRB030115: R-band observations at Asiago
  87. GRB030115: TAROT optical observations
  88. GRB 021211: VLT spectrum
  89. GRB 030115, no optical candidate
  90. GRB 030115, optical observations
  91. GRB 030115, optical candidate
  92. Possible GRB030113 seen by SPI ACS
  93. Probable GRB030112B seen by SPI ACS
  94. Probable GRB030112 seen by SPI ACS
  95. Information about where HETE will be pointing
  96. Possible GRB030111 seen by SPI ACS
  97. Possible GRB030110b seen by SPI ACS
  98. Possible GRB 030110 seen by SPI ACS
  99. IPN triangulation of GRB030109 (annulus)
  100. IPN triangulation of GRB030105 (large error box)

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