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 GRB030102B (refined localization - portion of annulus)
  2. Possible GRB 20030109 seen by SPI ACS
  3. IPN triangulation of GRB030102A - correction to peak flux
  4. IPN triangulation of GRB030102B (portion of annulus)
  5. IPN triangulation of GRB030102A (large error box)
  6. Coronas-F -Wind triangulation of GRB030102
  7. Possible GRB20030107 seen by SPI-ACS
  8. Possible GRB 20030105 seen by SPI ACS
  9. IPN triangulation of GRB030102 (annulus)
  10. GRB on 20030102 seen by SPI-ACS
  11. VLT spectroscopy of the probable host of GRB 021211
  12. GRB on 20030101 seen by SPI-ACS
  13. IPN triangulation of GRB030101 (two large error boxes)
  14. GRB021226
  15. GRB 021211: Probable Host and Underlying Supernova
  16. GRB 021226 registration by Helicon/Coronas-F
  17. Probable GRB in INTEGRAL SPI-ACS
  18. IPN triangulation of GRB021223 (two large error boxes)
  19. GRB021211, radio observations
  20. GRB 021112: Evidence for Another Dark Optical Afterglow
  21. GRB 021219: OSN optical observations
  22. GRB021219: Radio Observations
  23. GRB021219, optical observations
  24. IPN triangulation of GRB021219 - CORRECTION
  25. IPN triangulation of GRB021219
  26. GRB021219, optical observation by MASTER
  27. GRB021219: Correction to GCN 1766
  28. GRB021219 refined position with INTEGRAL
  29. VLT spectra of GRB 021211 revisited
  30. GRB021219: a long GRB localized by INTEGRAL
  31. GRB021211: APO optical observations
  32. IPN detection of continued activity from SGR1806-20
  33. IPN triangulation of GRB021215 (large error box)
  34. IPN triangulation of GRB021214 (annulus)
  35. XRF 020903 : HST observations
  36. GRB 021201: Optical Observations
  37. GRB 021211, optical observations
  38. GRB 021211: CTIO observations
  39. GRB021211: Measurement of Early Time Afterglow
  40. VLT spectrum of GRB 021211
  41. IPN triangulation of GRB021211B (two large error boxes)
  42. GRB 021211: early break in light curve
  43. GRB021211, BVRI field photometry
  44. GRB021211: Optical observations in CrAO
  45. GRB 021211, IR observations
  46. GRB 021211, optical observations
  47. GRB 021211: Optical Observations
  48. GRB021211: Kiso Observations
  49. GRB021204: Kiso Observations
  50. GRB 021201, optical observations
  51. GRB 021211: Radio Observations
  52. GRB021211: Optical observations
  53. GRB 021201 (short/hard), NOT observations
  54. SUB-MM SEARCH FOR GRB 021211
  55. Chandra observation of the IPN error box of GRB021201 (short/hard)
  56. GRB 021211 Milagro GeV/TeV Observations
  57. GRB 021211, R- and I-band observations
  58. GRB021211 - Upper limits from recent and historical observations
  59. GRB021211, OT at 108 s
  60. GRB021211 (HETE2493), OT at 143 sec
  61. GRB 021204: I-band Observations
  62. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  63. HETE 2493: Optical observations
  64. HETE 2493: Optical observations
  65. HETE 2493: Optical candidate
  66. GRB 021204: Optical Observations at RIKEN
  67. GRB 021125: Radio Observations
  68. IPN triangulation of GRB021206 (small error box)
  69. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  70. IPN detection of renewed activity from SGR1806-20
  71. IPN triangulation of GRB021205 (large error box)
  72. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  73. GRB021201, BVRcIc field photometry
  74. GRB 021201, Radio Observations
  75. GRB 021201: Optical Observations
  76. GRB 021201: BOOTES simultaneous optical observations
  77. IPN triangulation of GRB021201 (short/hard burst, small error box)
  78. Radio Catalog of GRB Afterglows
  79. GRB021004, late time optical observations
  80. GRB021004 Chandra Observation
  81. IPN detection of continued SGR1900+14 activity
  82. GRB021125 refined position
  83. IPN triangulation of GRB021115 (annulus)
  84. IPN triangulation of GRB021125B (two large error boxes)
  85. IPN triangulation of GRB021119 (large error box)
  86. IPN triangulation of GRB021125B (annulus)
  87. Improved IPN error box for GRB021125
  88. IPN BURST POSITION
  89. IPN triangulation of GRB021125 (INTEGRAL BURST)
  90. GRB021125 : A long GRB localized by INTEGRAL
  91. IPN confirmation of the reactivation of SGR1900+14
  92. IPN detection of possible reactivation of SGR1900+14
  93. GRB021113, SPI ACS observation
  94. IPN triangulation of GRB021119 (annulus)
  95. GRB 021112: Afterglow or Variable Star?
  96. GRB021113: optical observations at Bisei
  97. GRB 021113: Evidence for a Dark Optical Afterglow
  98. GRB 021112, Radio Observations
  99. GRB021112, BVRI field photometry
  100. GRB 021112: Variable Source in R-band search

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