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"

32494 results found.

  1. GRB030227, BVRcIc field photometry
  2. GRB030226, BVRcIc field calibration
  3. GRB 030227 optical afterglow
  4. GRB 030226: Steep Decline
  5. GRB 030227: Confirmed Optical Afterglow (S1-A)
  6. GRB 030226: R band polarimetric observations
  7. GRB 030226: Optical observations
  8. GRB 030227: fading of candidate optical afterglow 'S1-A'
  9. GRB030227:Optical observations
  10. GRB 20030226: Upper limits from recent and historical observations
  11. GRB 030227, possible optical counterpart of XMM-Newton source
  12. GRB030227 - faint tentative OT candidate
  13. GRB 030226, optical observations
  14. XMM-Newton observation of GRB030227
  15. GRB 030227: Kyoto optical observation
  16. GRB 030226, optical light curve
  17. GRB 030226 spectroscopy
  18. Possible break in the GRB 030226 light curve
  19. GRB030226: optical observation
  20. GRB 030226: Confirmed decay index
  21. GRB030226: ESI spectroscopy
  22. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  23. Two absorption systems in GRB 030226
  24. GRB 030226, optical observations
  25. GRB030226: optical observations and refined redshift
  26. GRB 030226, optical observations
  27. GRB 030226: Optical afterglow
  28. GRB 030217: Optical Observations at 4, 5, and 6 Days
  29. GRB: Non-Referencing of GCN Circulars.
  30. GRB030217: optical observations
  31. IPN triangulation of GRB030217 (small error box)
  32. GRB030115, WSRT radio observations - correction to GCN 1864
  33. GRB 030131: marginal optical detection
  34. GCN/INTEGRAL Mistake Fixed
  35. GRB 030204: Optical Observations
  36. GRB030204 field photometry
  37. GRB020819: Kiso R and I band observations
  38. GRB 030204: Correction to GCN 1856
  39. GRB030131: Candidate Optical Afterglow
  40. GRB 030115: Optical Observations
  41. GRB 030204, optical observations
  42. GRB 030131, optical observations
  43. GRB030131: Kiso optical limit for corrected position
  44. GRB030131: Optical limits for corrected position
  45. GRB 030131: afterglow candidate
  46. GRB 030115, late-time optical observations
  47. Type Ic SN2003L (SN/GRB?), optical spectrum
  48. GRB 020819: Host galaxy at Radio Position
  49. IPN triangulation of GRB030131 - CORRECTION
  50. IPN triangulation of GRB030131
  51. GRB030131: Optical limit
  52. GRB 030131 optical observations
  53. GRB030131: refined position
  54. GRB 030131 optical observations
  55. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  56. GRB030115 submm upper limit
  57. GRB 030115: Further IR observations with IRSF/SIRIUS
  58. Publicizing GRB Discoveries - A Message from NASA HQ
  59. GRB 030115, simultaneous observations by BOOTES-1
  60. GRB 030115: IR observations with IRSF/SIRIUS
  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. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  71. Distribution of INTEGRAL SPI-ACS triggers
  72. GRB030115: TAROT optical observations
  73. GRB 021211: VLT spectrum
  74. GRB 030115: APO Optical Observations
  75. GRB 030115, no optical candidate
  76. GRB 030115, optical observations
  77. GRB 030115, optical candidate
  78. IPN triangulation of GRB030109 (annulus)
  79. IPN triangulation of GRB030105 (large error box)
  80. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  81. Coronas-F -Wind triangulation of GRB030102
  82. IPN triangulation of GRB030102 (annulus)
  83. VLT spectroscopy of the probable host of GRB 021211
  84. GRB021226
  85. GRB 021211: Probable Host and Underlying Supernova
  86. GRB 021226 registration by Helicon/Coronas-F
  87. GRB 021112: Evidence for Another Dark Optical Afterglow
  88. GRB 021219: OSN optical observations
  89. GRB021219: Radio Observations
  90. GRB021219, optical observations
  91. IPN triangulation of GRB021219 - CORRECTION
  92. IPN triangulation of GRB021219
  93. GRB021219, optical observation by MASTER
  94. GRB021219: Correction to GCN 1766
  95. VLT spectra of GRB 021211 revisited
  96. GRB021219: a long GRB localized by INTEGRAL
  97. GRB021211: APO optical observations
  98. IPN detection of continued activity from SGR1806-20
  99. XRF 020903 : HST observations
  100. GRB 021201: Optical Observations

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