Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

25080 results found.

  1. GRB021112, BVRI field photometry
  2. GRB 021112: Variable Source in R-band search
  3. GRB021112: Optical Observations
  4. IPN triangulation of GRB021113 (=H2449; annulus)
  5. GRB 021113: Optical observations
  6. GRB 021112: RAPTOR Observations
  7. GRB021113 (=H2449): A Long GRB Localized by HETE
  8. GRB021112 (=H2448): A Long GRB Localized by HETE
  9. GRB 021016: Optical Observations
  10. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  11. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  12. SGR1900+14 activity, November 2-4, 2002
  13. GRB021104: optical observations
  14. Detection of activity from SGR 1900+14 with the RXTE/PCA
  15. IPN triangulation of GRB021027 (single large error box)
  16. IPN triangulation of GRB021027 (two large error boxes)
  17. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  18. GRB 021004: optical observations
  19. IPN triangulation of GRB021023 (small error boc)
  20. GRB 020813; likely host galaxy.
  21. IPN triangulation of GRB021020 (smaller error box)
  22. IPN triangulation of GRB021020
  23. GRB 021008, optical observations
  24. IPN triangulation of GRB021016 (small error box)
  25. IPN triangulation of GRB021014 (large error box)
  26. IPN triangulation of GRB021013 (single error box)
  27. GRB 021004: optical spectroscopy on Oct 11
  28. IPN triangulation of GRB021013 (two small error boxes)
  29. GRB021004: High-resolution optical spectroscopy
  30. XRF 020903: flattening of the optical light curve.
  31. GRB021004, UBVRcIc field photometry update
  32. IPN triangulation of GRB021008 (single error box)
  33. GRB 021004 submm observations
  34. IPN triangulation of GRB021008 (two small error boxes)
  35. GRB021004 Chandra HETG Observations
  36. GRB 021004: Optical/NIR Observations
  37. GRB 021004: Additional V-band Polarimetric Observations
  38. GRB021004: optical observation
  39. GRB 021004: Host Galaxy Star Formation Rate
  40. GRB 021004 submm observations
  41. GRB 021004: WC wind?
  42. GRB021004: NIR and Optical observations
  43. GRB 021004: Optical observations, AUDE network
  44. GRB 021004 - VLA Radio Observations
  45. GRB 021004 - Unusual Radio-to-Submm Spectrum
  46. GRB 021004: optical spectroscopy
  47. IPN triangulation of GRB021007 (annulus)
  48. GRB021004: optical observations and predicted break time
  49. GRB021004: BVRc photometry
  50. GRB021004 radio observation
  51. HETE fluences for GRB021004
  52. GRB 021004: Optical Photometry at 2.5 Days
  53. GRB 021004: polarimetric observations
  54. GRB 021004: V-band Polarimetric Observations
  55. GRB021004: Update Bisei photometric data
  56. IRAM Millimeter detection of GRB 021004
  57. GRB 021004 radio observation
  58. GRB 021004: Optical Photometry at 1.5 Days
  59. GRB021004, BVRcIc field photometry
  60. GRB021004: Optical Spectroscopy
  61. GRB 021004 radio search
  62. XRF020903, BVRI field photometry
  63. XRF020903: TNG and Asiago photometry
  64. GRB 020903: Optical observations at RIKEN
  65. XRF 020903: Correction to GCN 1560
  66. XRF 020903: VRI observations
  67. XRF 020903: R band observations
  68. XRF 020903: Archival Optical Images
  69. Radio Observations of XRF 020903: The Missing Link
  70. XRF 020903: Supernova
  71. IPN triangulation of GRB020923 (two error boxes)
  72. IPN triangulation of GRB020914B
  73. IPN triangulation of GRB020911 (2 large error boxes)
  74. GRB 020305: HST/STIS observations
  75. Confirmation of IPN error box for GRB020910
  76. IPN triangulation of GRB020910
  77. IPN GCN Circulars now to be issued without restriction
  78. Single IPN error box for GRB020904
  79. XRF 020903: optical observation at Kyoto
  80. GRB020322 : HST/STIS observations
  81. XRF 020903: Optical observations
  82. IPN triangulation of GRB020904
  83. INTEGRAL GRBs added to GCN
  84. SGR1900+14 burst localized by HETE
  85. GRB020813: High-resolution optical spectroscopy
  86. GRB020812: negative optical observations
  87. GRB 020812: optical observation at Kyoto University
  88. Second epoch K band imaging of GRB 020819
  89. GRB 020813 : HST observations
  90. GRB 020812: early time optical observation at Ouda Station
  91. GRB020813: Magellan BVRI Photometry
  92. GRB 020819: Optical observations
  93. K band observation of GRB 020819
  94. GRB020813: optical and NIR observations
  95. GRB020813: Fading X-ray Afterglow Observed with Chandra
  96. GRB020813, UBVRI field calibration
  97. GRB020812: NIR observations
  98. Polarimetry of GRB020813: evidence for variability
  99. GRB020813 IRAM millimeter observations
  100. GRB020812: optical observations

Advanced

Download all Circulars as a .tar.gz archive:
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