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"

32503 results found.

  1. IPN triangulation of GRB030306 (two small error boxes)
  2. GRB 030226: Optical observations
  3. GRB030226: Analysis of Chandra data
  4. GRB 030227: Optical observations
  5. GRB030226, BVRc observations
  6. Chandra detection of the X-ray afterglow of GRB 030226
  7. GRB 030226, further optical/NIR imaging
  8. GRB 030226: Ic Observations
  9. GRB030227: Kiso optical upper limit
  10. GRB030227, BVRcIc field photometry
  11. GRB030226, BVRcIc field calibration
  12. GRB 030227 optical afterglow
  13. GRB 030226: Steep Decline
  14. GRB 030227: Confirmed Optical Afterglow (S1-A)
  15. GRB 030226: R band polarimetric observations
  16. GRB 030226: Optical observations
  17. GRB 030227: fading of candidate optical afterglow 'S1-A'
  18. GRB030227:Optical observations
  19. GRB 20030226: Upper limits from recent and historical observations
  20. GRB 030227, possible optical counterpart of XMM-Newton source
  21. GRB030227 - faint tentative OT candidate
  22. GRB 030226, optical observations
  23. XMM-Newton observation of GRB030227
  24. GRB 030227: Kyoto optical observation
  25. GRB 030226, optical light curve
  26. GRB 030226 spectroscopy
  27. Possible break in the GRB 030226 light curve
  28. GRB030226: optical observation
  29. GRB 030226: Confirmed decay index
  30. GRB030226: ESI spectroscopy
  31. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  32. Two absorption systems in GRB 030226
  33. GRB 030226, optical observations
  34. GRB030226: optical observations and refined redshift
  35. GRB 030226, optical observations
  36. GRB 030226: Optical afterglow
  37. GRB 030217: Optical Observations at 4, 5, and 6 Days
  38. GRB: Non-Referencing of GCN Circulars.
  39. GRB030217: optical observations
  40. IPN triangulation of GRB030217 (small error box)
  41. GRB030115, WSRT radio observations - correction to GCN 1864
  42. GRB 030131: marginal optical detection
  43. GCN/INTEGRAL Mistake Fixed
  44. GRB 030204: Optical Observations
  45. GRB030204 field photometry
  46. GRB020819: Kiso R and I band observations
  47. GRB 030204: Correction to GCN 1856
  48. GRB030131: Candidate Optical Afterglow
  49. GRB 030115: Optical Observations
  50. GRB 030204, optical observations
  51. GRB 030131, optical observations
  52. GRB030131: Kiso optical limit for corrected position
  53. GRB030131: Optical limits for corrected position
  54. GRB 030131: afterglow candidate
  55. GRB 030115, late-time optical observations
  56. Type Ic SN2003L (SN/GRB?), optical spectrum
  57. GRB 020819: Host galaxy at Radio Position
  58. IPN triangulation of GRB030131 - CORRECTION
  59. IPN triangulation of GRB030131
  60. GRB030131: Optical limit
  61. GRB 030131 optical observations
  62. GRB030131: refined position
  63. GRB 030131 optical observations
  64. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  65. GRB030115 submm upper limit
  66. GRB 030115: Further IR observations with IRSF/SIRIUS
  67. Publicizing GRB Discoveries - A Message from NASA HQ
  68. GRB 030115, simultaneous observations by BOOTES-1
  69. GRB 030115: IR observations with IRSF/SIRIUS
  70. GRB030115: R-band counterpart of IR candidate
  71. GRB030115, afterglow candidate
  72. GRB 021211: R-band observations at late-time
  73. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  74. IPN triangulation of GRB030115B (small error box)
  75. GRB 030115 : Possible IR counterpart
  76. GRB 030115: Radio Observations
  77. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  78. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  79. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  80. Distribution of INTEGRAL SPI-ACS triggers
  81. GRB030115: TAROT optical observations
  82. GRB 021211: VLT spectrum
  83. GRB 030115: APO Optical Observations
  84. GRB 030115, no optical candidate
  85. GRB 030115, optical observations
  86. GRB 030115, optical candidate
  87. IPN triangulation of GRB030109 (annulus)
  88. IPN triangulation of GRB030105 (large error box)
  89. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  90. Coronas-F -Wind triangulation of GRB030102
  91. IPN triangulation of GRB030102 (annulus)
  92. VLT spectroscopy of the probable host of GRB 021211
  93. GRB021226
  94. GRB 021211: Probable Host and Underlying Supernova
  95. GRB 021226 registration by Helicon/Coronas-F
  96. GRB 021112: Evidence for Another Dark Optical Afterglow
  97. GRB 021219: OSN optical observations
  98. GRB021219: Radio Observations
  99. GRB021219, optical observations
  100. IPN triangulation of GRB021219 - CORRECTION

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