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"

28096 results found.

  1. GRB021211: Optical observations in CrAO
  2. GRB 021211, IR observations
  3. GRB 021211, optical observations
  4. GRB021211: Kiso Observations
  5. GRB021204: Kiso Observations
  6. GRB021211: Optical observations
  7. GRB 021211, R- and I-band observations
  8. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  9. HETE 2493: Optical observations
  10. HETE 2493: Optical observations
  11. IPN detection of renewed activity from SGR1806-20
  12. GRB021201, BVRcIc field photometry
  13. IPN detection of continued SGR1900+14 activity
  14. GRB021125 : A long GRB localized by INTEGRAL
  15. IPN detection of possible reactivation of SGR1900+14
  16. GRB 021112: Afterglow or Variable Star?
  17. GRB 021113: Evidence for a Dark Optical Afterglow
  18. GRB021112, BVRI field photometry
  19. GRB 021113: Optical observations
  20. GRB021004: Near infrared spectroscopy
  21. GRB021104: optical observations
  22. GRB021104: Candidate present in DSS
  23. GRB021104: possible optical afterglow
  24. Detection of activity from SGR 1900+14 with the RXTE/PCA
  25. GRB021004, late-time optical observations
  26. GRB021004: Optical Observations
  27. GRB 020813; likely host galaxy.
  28. GRB 021016, optical observations
  29. GRB 021008, optical observations
  30. GRB021004: Optical Observations
  31. GRB 021004: optical spectroscopy on Oct 11
  32. GRB021004: High-resolution optical spectroscopy
  33. GRB021004, UBVRcIc field photometry update
  34. GRB021004: Optical Observations
  35. GRB021004 Chandra HETG Observations
  36. GRB021004: optical observation
  37. GRB 021004: WC wind?
  38. GRB 021004: Optical observations, AUDE network
  39. GRB 021004 - VLA Radio Observations
  40. GRB 021004 - Unusual Radio-to-Submm Spectrum
  41. GRB 021004: optical spectroscopy
  42. GRB021004: optical observations and predicted break time
  43. GRB021004: BVRc photometry
  44. GRB 021004 redshift
  45. GRB021004: restart of optical decay
  46. GRB 021004: Optical Decay
  47. GRB 021004, spectroscopic observations
  48. GRB021004: not fading anymore?
  49. GRB 021004: Optical Photometry at 2.5 Days
  50. GRB 021004: polarimetric observations
  51. GRB021004: Update Bisei photometric data
  52. GRB 021004: Optical Decay
  53. GRB021004, astrometric position
  54. GRB021004, Optical Observations
  55. IRAM Millimeter detection of GRB 021004
  56. GRB 021004: Optical observations at RIKEN
  57. GRB021004: continued fading
  58. GRB 021004: Optical Photometry at 1.5 Days
  59. GRB021004, Optical Observations
  60. GRB021004, BVRcIc field photometry
  61. GRB 021004: optical counterpart
  62. GRB 021004: Optical Observations
  63. GRB 021004, SPM optical observations
  64. GRB 021004, optical observations
  65. GRB 021004 radio search
  66. GRB 021004: radio observations
  67. GRB 021004: steepening of the optical decay slope
  68. GRB021004: optical observations at Nyrola
  69. GRB021004: Absorption redshift
  70. GRB 021004: Kyoto observation
  71. GRB021004: Optical Afterglow
  72. XRF 020903: Correction to GCN 1560
  73. Radio Observations of XRF 020903: The Missing Link
  74. XRF 020903: Supernova
  75. GRB 020305: HST/STIS observations
  76. XRF 020903: optical observation at Kyoto
  77. GRB020322 : HST/STIS observations
  78. XRF 020903: Optical observations
  79. IPN detection of a burst from SGR1900+14
  80. XRF 020903, optical observations
  81. GRB020813: High-resolution optical spectroscopy
  82. Second epoch K band imaging of GRB 020819
  83. Confirming no variability for GRB02081
  84. GRB 020819: Optical observations
  85. K band observation of GRB 020819
  86. HETE 2275: Optical observations
  87. GRB020813: Fading X-ray Afterglow Observed with Chandra
  88. GRB 020813: addendum to GCN 1498
  89. GRB020813: optical observations at Bisei
  90. GRB020813: V-band decay slope
  91. Polarimetry of GRB020813: evidence for variability
  92. GRB020813 IRAM millimeter observations
  93. GRB020813(=H2262): Revised Localization with HETE SXC
  94. GRB020813: Early Time Magnitude
  95. GRB020813: optical observations; possible host galaxy
  96. GRB 020813, radio detection
  97. GRB 020812 : optical afterglow candidate
  98. GRB020812: optical observations
  99. GRB020813, optical observations
  100. GRB020812: possible afterglow candidate

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