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"
  1. IPN triangulation of GRB030119 (two large error boxes)
  2. GRB 030115: Further IR observations with IRSF/SIRIUS
  3. IPN triangulation of GRB030117 (two large error boxes)
  4. Publicizing GRB Discoveries - A Message from NASA HQ
  5. GRB 030115: Radio detection of IR candidate
  6. GRB 030115, simultaneous observations by BOOTES-1
  7. GRB 030115: IR observations with IRSF/SIRIUS
  8. IPN triangulation of GRB030115C (large error box)
  9. GRB030115: R-band counterpart of IR candidate
  10. GRB030115, afterglow candidate
  11. GRB 021211: R-band observations at late-time
  12. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  13. IPN triangulation of GRB030115B (small error box)
  14. GRB 030115 : Possible IR counterpart
  15. GRB 030115: Radio Observations
  16. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  17. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  18. IPN triangulation of GRB030115B (annulus)
  19. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  20. Distribution of INTEGRAL SPI-ACS triggers
  21. GRB030115: R-band observations at Asiago
  22. GRB030115: TAROT optical observations
  23. GRB 021211: VLT spectrum
  24. GRB 030115: APO Optical Observations
  25. GRB 030115, no optical candidate
  26. GRB 030115, optical observations
  27. GRB 030115, optical candidate
  28. Possible GRB030113 seen by SPI ACS
  29. Probable GRB030112B seen by SPI ACS
  30. Probable GRB030112 seen by SPI ACS
  31. Information about where HETE will be pointing
  32. Possible GRB030111 seen by SPI ACS
  33. Possible GRB030110b seen by SPI ACS
  34. Possible GRB 030110 seen by SPI ACS
  35. IPN triangulation of GRB030109 (annulus)
  36. IPN triangulation of GRB030105 (large error box)
  37. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  38. Possible GRB 20030109 seen by SPI ACS
  39. IPN triangulation of GRB030102A - correction to peak flux
  40. IPN triangulation of GRB030102B (portion of annulus)
  41. IPN triangulation of GRB030102A (large error box)
  42. Coronas-F -Wind triangulation of GRB030102
  43. Possible GRB20030107 seen by SPI-ACS
  44. Possible GRB 20030105 seen by SPI ACS
  45. IPN triangulation of GRB030102 (annulus)
  46. GRB on 20030102 seen by SPI-ACS
  47. VLT spectroscopy of the probable host of GRB 021211
  48. GRB on 20030101 seen by SPI-ACS
  49. IPN triangulation of GRB030101 (two large error boxes)
  50. GRB021226
  51. GRB 021211: Probable Host and Underlying Supernova
  52. GRB 021226 registration by Helicon/Coronas-F
  53. Probable GRB in INTEGRAL SPI-ACS
  54. IPN triangulation of GRB021223 (two large error boxes)
  55. GRB021211, radio observations
  56. GRB 021112: Evidence for Another Dark Optical Afterglow
  57. GRB 021219: OSN optical observations
  58. GRB021219: Radio Observations
  59. GRB021219, optical observations
  60. IPN triangulation of GRB021219 - CORRECTION
  61. IPN triangulation of GRB021219
  62. GRB021219, optical observation by MASTER
  63. GRB021219: Correction to GCN 1766
  64. GRB021219 refined position with INTEGRAL
  65. VLT spectra of GRB 021211 revisited
  66. GRB021219: a long GRB localized by INTEGRAL
  67. GRB021211: APO optical observations
  68. IPN detection of continued activity from SGR1806-20
  69. IPN triangulation of GRB021215 (large error box)
  70. IPN triangulation of GRB021214 (annulus)
  71. XRF 020903 : HST observations
  72. GRB 021201: Optical Observations
  73. GRB 021211, optical observations
  74. GRB 021211: CTIO observations
  75. GRB021211: Measurement of Early Time Afterglow
  76. VLT spectrum of GRB 021211
  77. IPN triangulation of GRB021211B (two large error boxes)
  78. GRB 021211: early break in light curve
  79. GRB021211, BVRI field photometry
  80. GRB021211: Optical observations in CrAO
  81. GRB 021211, IR observations
  82. GRB 021211, optical observations
  83. GRB 021211: Optical Observations
  84. GRB021211: Kiso Observations
  85. GRB021204: Kiso Observations
  86. GRB 021201, optical observations
  87. GRB 021211: Radio Observations
  88. GRB021211: Optical observations
  89. GRB 021201 (short/hard), NOT observations
  90. SUB-MM SEARCH FOR GRB 021211
  91. Chandra observation of the IPN error box of GRB021201 (short/hard)
  92. GRB 021211 Milagro GeV/TeV Observations
  93. GRB 021211, R- and I-band observations
  94. GRB021211 - Upper limits from recent and historical observations
  95. GRB021211, OT at 108 s
  96. GRB021211 (HETE2493), OT at 143 sec
  97. GRB 021204: I-band Observations
  98. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  99. HETE 2493: Optical observations
  100. HETE 2493: 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