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"

28052 results found.

  1. GRB021004: High-resolution optical spectroscopy
  2. XRF 020903: flattening of the optical light curve.
  3. GRB021004, UBVRcIc field photometry update
  4. IPN triangulation of GRB021008 (single error box)
  5. GRB 021004 submm observations
  6. IPN triangulation of GRB021008 (two small error boxes)
  7. GRB021004 Chandra HETG Observations
  8. GRB 021004: Optical/NIR Observations
  9. GRB 021004: Additional V-band Polarimetric Observations
  10. GRB021004: optical observation
  11. GRB 021004: Host Galaxy Star Formation Rate
  12. GRB 021004 submm observations
  13. GRB 021004: WC wind?
  14. GRB021004: NIR and Optical observations
  15. GRB 021004: Optical observations, AUDE network
  16. GRB 021004 - VLA Radio Observations
  17. GRB 021004 - Unusual Radio-to-Submm Spectrum
  18. GRB 021004: optical spectroscopy
  19. IPN triangulation of GRB021007 (annulus)
  20. GRB021004: optical observations and predicted break time
  21. GRB021004: BVRc photometry
  22. GRB021004 radio observation
  23. HETE fluences for GRB021004
  24. GRB 021004: Optical Photometry at 2.5 Days
  25. GRB 021004: polarimetric observations
  26. GRB 021004: V-band Polarimetric Observations
  27. GRB021004: Update Bisei photometric data
  28. IRAM Millimeter detection of GRB 021004
  29. GRB 021004 radio observation
  30. GRB 021004: Optical Photometry at 1.5 Days
  31. GRB021004, BVRcIc field photometry
  32. GRB021004: Optical Spectroscopy
  33. GRB 021004 radio search
  34. XRF020903, BVRI field photometry
  35. XRF020903: TNG and Asiago photometry
  36. GRB 020903: Optical observations at RIKEN
  37. XRF 020903: Correction to GCN 1560
  38. XRF 020903: VRI observations
  39. XRF 020903: R band observations
  40. XRF 020903: Archival Optical Images
  41. Radio Observations of XRF 020903: The Missing Link
  42. XRF 020903: Supernova
  43. IPN triangulation of GRB020923 (two error boxes)
  44. IPN triangulation of GRB020914B
  45. IPN triangulation of GRB020911 (2 large error boxes)
  46. GRB 020305: HST/STIS observations
  47. Confirmation of IPN error box for GRB020910
  48. IPN triangulation of GRB020910
  49. IPN GCN Circulars now to be issued without restriction
  50. Single IPN error box for GRB020904
  51. XRF 020903: optical observation at Kyoto
  52. GRB020322 : HST/STIS observations
  53. XRF 020903: Optical observations
  54. IPN triangulation of GRB020904
  55. INTEGRAL GRBs added to GCN
  56. SGR1900+14 burst localized by HETE
  57. GRB020813: High-resolution optical spectroscopy
  58. GRB020812: negative optical observations
  59. GRB 020812: optical observation at Kyoto University
  60. Second epoch K band imaging of GRB 020819
  61. GRB 020813 : HST observations
  62. GRB 020812: early time optical observation at Ouda Station
  63. GRB020813: Magellan BVRI Photometry
  64. GRB 020819: Optical observations
  65. K band observation of GRB 020819
  66. GRB020813: optical and NIR observations
  67. GRB020813: Fading X-ray Afterglow Observed with Chandra
  68. GRB020813, UBVRI field calibration
  69. GRB020812: NIR observations
  70. Polarimetry of GRB020813: evidence for variability
  71. GRB020813 IRAM millimeter observations
  72. GRB020812: optical observations
  73. GRB020813: High-Resolution Optical Observations
  74. GRB 020812: optical observation at Bisei
  75. GRB020813: Early Time Magnitude
  76. Millimeter observation of GRB 020813
  77. GRB020812: optical observations
  78. GRB 020813 : KISO multiband optical observations
  79. GRB020813, optical observations
  80. IPN error box for GRB020813
  81. GRB020813, astrometric position
  82. Spectropolarimetry of GRB 020813
  83. GRB 020812 optical observation
  84. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  85. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  86. HST Imaging of the Host of GRB 011121
  87. GRB020801, optical afterglow candidate
  88. GRB020331: Late-time Optical Light Curve (re-submission)
  89. GRB020331: Late-time Optical Light Curve
  90. IPN triangulation of GRB020714
  91. IPN triangulation of GRB020715 (=GRB150702)
  92. IPN triangulation of GRB020714
  93. IPN triangulation of GRB150702
  94. GRB 020410: Discovery of Probable OT by HST
  95. GRB 020124, HST observations of the fading afterglow
  96. IPN triangulation of GRB020708
  97. IPN triangulation of GRB020708
  98. Correction to IPN error box for GRB020706
  99. IPN triangulation of GRB020706
  100. GRB 020705: 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