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"

15252 results found.

  1. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  2. GRB030323, ROTSE-III detection of possible optical counterpart
  3. GRB030323, optical observations
  4. GRB 030320: Optical Observations
  5. IPN upper limit to a GRB associated with SN2003L
  6. IPN triangulation of GRB030306 (single small error box - REVISED)
  7. IPN triangulation of GRB030306 (intense; annulus only so far)
  8. GRB 030226: Optical observations
  9. GRB030226: Analysis of Chandra data
  10. GRB 030226, further optical/NIR imaging
  11. GRB 030226: Optical observations
  12. GRB 030227, possible optical counterpart of XMM-Newton source
  13. GRB030227 - faint tentative OT candidate
  14. XMM-Newton observation of GRB030227
  15. GRB 030227: Kyoto optical observation
  16. GRB 030226, optical light curve
  17. GRB 030226 spectroscopy
  18. GRB030227: refined INTEGRAL position
  19. GRB 030226 : Predicted light curve
  20. GRB 030226: Confirmed decay index
  21. GRB030226: ESI spectroscopy
  22. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  23. GRB030226: optical observations and refined redshift
  24. GRB 030226: Optical afterglow
  25. GRB: Non-Referencing of GCN Circulars.
  26. GRB020819: Kiso R and I band observations
  27. GRB 030131, optical observations
  28. GRB 030131: afterglow candidate
  29. GRB 030115, late-time optical observations
  30. GRB030131: corrected INTEGRAL position
  31. GRB030131: Kiso Observations
  32. GRB 020819: Host galaxy at Radio Position
  33. GRB030131: refined position
  34. Publicizing GRB Discoveries - A Message from NASA HQ
  35. GRB030115: R-band counterpart of IR candidate
  36. GRB 021211: R-band observations at late-time
  37. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  38. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  39. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  40. GRB030115: TAROT optical observations
  41. GRB 030115: APO Optical Observations
  42. GRB 030115, no optical candidate
  43. VLT spectroscopy of the probable host of GRB 021211
  44. GRB 021211: Probable Host and Underlying Supernova
  45. GRB021219: Correction to GCN 1766
  46. VLT spectra of GRB 021211 revisited
  47. GRB021219: a long GRB localized by INTEGRAL
  48. GRB021211: APO optical observations
  49. GRB021211: Measurement of Early Time Afterglow
  50. GRB021211: Optical observations in CrAO
  51. GRB 021211: Optical Observations
  52. GRB021211: Optical observations
  53. GRB 021201 (short/hard), NOT observations
  54. GRB 021211 Milagro GeV/TeV Observations
  55. GRB021211, OT at 108 s
  56. GRB021211 (HETE2493), OT at 143 sec
  57. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  58. HETE 2493: Optical observations
  59. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  60. IPN detection of renewed activity from SGR1806-20
  61. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  62. GRB021125 : A long GRB localized by INTEGRAL
  63. GRB021113, SPI ACS observation
  64. GRB 021112, Radio Observations
  65. GRB 021112: Variable Source in R-band search
  66. GRB021112: Optical Observations
  67. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  68. GRB021113 (=H2449): A Long GRB Localized by HETE
  69. GRB021112 (=H2448): A Long GRB Localized by HETE
  70. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  71. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  72. SGR1900+14 activity, November 2-4, 2002
  73. Spectropolarimetry of GRB021004
  74. GRB021104: optical observations
  75. GRB021104: Candidate present in DSS
  76. Detection of activity from SGR 1900+14 with the RXTE/PCA
  77. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  78. GRB021004: Optical Observations
  79. GRB 020813; likely host galaxy.
  80. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  81. GRB 021004: VRI observations at TNG: possible break
  82. GRB 021008, optical observations
  83. GRB021016(=H2397): A Long GRB Localized by HETE
  84. GRB021004: Optical Observations
  85. GRB 021004: optical spectroscopy on Oct 11
  86. GRB021004: High-resolution optical spectroscopy
  87. GRB021004: Optical Observations
  88. GRB021004 Chandra HETG Observations
  89. GRB 021004: Host Galaxy Star Formation Rate
  90. GRB 021004: WC wind?
  91. GRB 021004: Optical observations, AUDE network
  92. GRB 021004 - Unusual Radio-to-Submm Spectrum
  93. GRB 021004: optical spectroscopy
  94. XRF 020903 spectrum
  95. GRB 021004: HST/STIS spectroscopic observations
  96. GRB021004: optical observations and predicted break time
  97. GRB 021004 redshift
  98. GRB 021004 continued IR fading
  99. HETE fluences for GRB021004
  100. GRB021004: Update Bisei photometric data

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