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"

35948 results found.

  1. IPN triangulation of GRB030306 (single small error box)
  2. IPN triangulation of GRB030306 (two small error boxes)
  3. IPN triangulation of GRB030306 (intense; annulus only so far)
  4. GRB 030226: Optical observations
  5. IPN triangulation of GRB030304 (annulus)
  6. GRB 030227: Optical observations
  7. GRB030226, BVRc observations
  8. Chandra detection of the X-ray afterglow of GRB 030226
  9. GRB 030226, further optical/NIR imaging
  10. GRB030227, optical observations
  11. GRB 030226: Ic Observations
  12. GRB030227: Kiso optical upper limit
  13. IPN triangulation of GRB030301 (annulus)
  14. IPN triangulation of GRB030228 (annulus)
  15. GRB030227, BVRcIc field photometry
  16. GRB030226, BVRcIc field calibration
  17. GRB 030227 optical afterglow
  18. 030302: NOT A GRB
  19. 030228: NOT A GRB
  20. GRB 030228, optical observations
  21. GRB 030226: Steep Decline
  22. GRB 030227: Confirmed Optical Afterglow (S1-A)
  23. GRB 030226: R band polarimetric observations
  24. GRB 030226: Optical observations
  25. GRB 030227: fading of candidate optical afterglow 'S1-A'
  26. GRB030227:Optical observations
  27. GRB 20030226: Upper limits from recent and historical observations
  28. GRB 030227, possible optical counterpart of XMM-Newton source
  29. GRB030227 - faint tentative OT candidate
  30. GRB 030226, optical observations
  31. GRB030227: Kiso optical observations
  32. GRB 030227: Kyoto optical observation
  33. GRB 030226, optical light curve
  34. GRB 030226 spectroscopy
  35. Possible break in the GRB 030226 light curve
  36. GRB 030226 : Predicted light curve
  37. IPN triangulation of GRB030225 (annulus)
  38. GRB 030226: Confirmed decay index
  39. GRB030226: ESI spectroscopy
  40. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  41. GRB 030226 simultaneous optical observations
  42. Two absorption systems in GRB 030226
  43. GRB 030226, optical observations
  44. GRB 030226 Optical Spectra and R,I,z' Imaging
  45. GRB 030226, optical observations
  46. GRB 030226: Optical afterglow
  47. GRB 030217: Optical Observations at 4, 5, and 6 Days
  48. IPN triangulation of GRB030223 (annulus)
  49. IPN triangulation of GRB030220 (annulus)
  50. GRB: Non-Referencing of GCN Circulars.
  51. IPN triangulation of GRB030218 (annulus)
  52. IPN triangulation of GRB030217 (small error box)
  53. IPN triangulation of GRB030215C (annulus)
  54. IPN triangulation of GRB030217 (annulus)
  55. IPN triangulation of GRB030216 (annulus)
  56. IPN triangulation of GRB030215A and GRB030215B (annuli)
  57. GRB030115, WSRT radio observations - correction to GCN 1864
  58. GRB 030131: marginal optical detection
  59. GRB030115, WSRT radio observations
  60. IPN triangulation of GRB030206 (annulus)
  61. IPN triangulation of GRB030208 (annulus)
  62. GRB 030204: Optical Observations
  63. GRB030204 field photometry
  64. GRB020819: Kiso R and I band observations
  65. GRB 030204: Correction to GCN 1856
  66. GRB 030115: Optical Observations
  67. GRB 030204, optical observations
  68. IPN triangulation of GRB030204 (small error box)
  69. IPN triangulation of GRB030202 (annulus)
  70. GRB 030131, optical observations
  71. GRB030131: Kiso optical limit for corrected position
  72. GRB030131: Optical limits for corrected position
  73. GRB 030131: afterglow candidate
  74. GRB 030115, late-time optical observations
  75. GRB030131: corrected INTEGRAL position
  76. Type Ic SN2003L (SN/GRB?), optical spectrum
  77. GRB030131: Kiso Observations
  78. GRB 020819: Host galaxy at Radio Position
  79. IPN triangulation of GRB030131 - CORRECTION
  80. GRB 020819: afterglow candidate
  81. IPN triangulation of GRB030131
  82. GRB 030131 optical observations
  83. GRB 030131 optical observations
  84. A long GRB detected by INTEGRAL
  85. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  86. Type Ic SN2003L (SN/GRB?) Radio Observations
  87. IPN triangulation of GRB030127 (annulus)
  88. GRB030115 submm upper limit
  89. IPN triangulation of GRB030119 (two large error boxes)
  90. GRB 030115: Further IR observations with IRSF/SIRIUS
  91. IPN triangulation of GRB030117 (two large error boxes)
  92. Publicizing GRB Discoveries - A Message from NASA HQ
  93. GRB 030115: Radio detection of IR candidate
  94. GRB 030115, simultaneous observations by BOOTES-1
  95. GRB 030115: IR observations with IRSF/SIRIUS
  96. IPN triangulation of GRB030115C (large error box)
  97. GRB030115: R-band counterpart of IR candidate
  98. GRB030115, afterglow candidate
  99. GRB 021211: R-band observations at late-time
  100. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)

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