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"

22056 results found.

  1. GRB030115 submm upper limit
  2. GRB 030115: Further IR observations with IRSF/SIRIUS
  3. GRB 030115: Radio detection of IR candidate
  4. GRB 030115, simultaneous observations by BOOTES-1
  5. GRB 030115: IR observations with IRSF/SIRIUS
  6. GRB 021211: R-band observations at late-time
  7. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  8. GRB 030115 : Possible IR counterpart
  9. GRB 030115: Radio Observations
  10. GRB030115: R-band observations at Asiago
  11. GRB030115: TAROT optical observations
  12. GRB 030115: APO Optical Observations
  13. GRB 030115, no optical candidate
  14. GRB 030115, optical observations
  15. GRB 030115, optical candidate
  16. Information about where HETE will be pointing
  17. VLT spectroscopy of the probable host of GRB 021211
  18. GRB 021211: Probable Host and Underlying Supernova
  19. GRB021211, radio observations
  20. GRB 021219: OSN optical observations
  21. GRB021219: Radio Observations
  22. GRB021219, optical observations
  23. IPN triangulation of GRB021219
  24. VLT spectra of GRB 021211 revisited
  25. GRB021211: APO optical observations
  26. XRF 020903 : HST observations
  27. GRB 021201: Optical Observations
  28. GRB 021211, optical observations
  29. GRB 021211: CTIO observations
  30. GRB 021211: early break in light curve
  31. GRB021211: Optical observations in CrAO
  32. GRB 021211, IR observations
  33. GRB 021211, optical observations
  34. GRB 021211: Optical Observations
  35. GRB021211: Kiso Observations
  36. GRB021204: Kiso Observations
  37. GRB 021201, optical observations
  38. GRB 021211: Radio Observations
  39. GRB021211: Optical observations
  40. GRB 021201 (short/hard), NOT observations
  41. SUB-MM SEARCH FOR GRB 021211
  42. GRB 021211 Milagro GeV/TeV Observations
  43. GRB 021211, R- and I-band observations
  44. GRB021211 - Upper limits from recent and historical observations
  45. GRB021211, OT at 108 s
  46. GRB 021204: I-band Observations
  47. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  48. HETE 2493: Optical observations
  49. HETE 2493: Optical observations
  50. HETE 2493: Optical candidate
  51. GRB 021204: Optical Observations at RIKEN
  52. GRB 021125: Radio Observations
  53. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  54. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  55. GRB 021201, Radio Observations
  56. GRB 021201: Optical Observations
  57. GRB 021201: BOOTES simultaneous optical observations
  58. GRB021004, late time optical observations
  59. GRB021113: optical observations at Bisei
  60. GRB 021113: Evidence for a Dark Optical Afterglow
  61. GRB 021112, Radio Observations
  62. GRB 021112: Variable Source in R-band search
  63. GRB021112: Optical Observations
  64. GRB021113: Kiso Observations
  65. GRB 021113: Optical observations
  66. GRB 021112: RAPTOR Observations
  67. GRB 021113: Optical Observations
  68. GRB 021113: Optical Observations
  69. GRB 021112: Optical Observations
  70. GRB 021112: R-band search
  71. GRB 021016: Optical Observations
  72. GRB021004: Near infrared spectroscopy
  73. GRB021104: Optical Observations
  74. GRB021104: Optical observations
  75. GRB021104: optical observations
  76. Detection of activity from SGR 1900+14 with the RXTE/PCA
  77. GRB021004, late-time optical observations
  78. GRB 021023: Infrared Imaging
  79. GRB 021004: optical observations
  80. GRB021004: Optical Observations
  81. GRB 020813; likely host galaxy.
  82. GRB 021008, radio observations
  83. GRB 021016, optical observations
  84. GRB 021004: VRI observations at TNG: possible break
  85. GRB021016, optical observations
  86. GRB 021008, optical observations
  87. GRB021004: Optical Observations
  88. GRB021004: High-resolution optical spectroscopy
  89. IPN triangulation of GRB021013 (annulus)
  90. XRF 020903: flattening of the optical light curve.
  91. GRB021004: Optical Observations
  92. GRB 021004 submm observations
  93. GRB021004 Chandra HETG Observations
  94. GRB 021004: Optical/NIR Observations
  95. GRB 021004: Additional V-band Polarimetric Observations
  96. GRB 021004 submm observations
  97. GRB021004: NIR and Optical observations
  98. GRB 021004: Optical observations, AUDE network
  99. GRB 021004 - VLA Radio Observations
  100. GRB 021004 - Unusual Radio-to-Submm Spectrum

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