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"

41624 results found.

  1. GRB031111, optical observations
  2. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  3. GRB031203: Chandra Observations
  4. GRB040106, follow-up radio observations
  5. GRB040106: refined X-ray transient position
  6. SN 2003dh/GRB030329 late-time optical spectroscopy
  7. GRB040106, Radio Observations
  8. GRB040106, likely optical afterglow
  9. GRB040106: Second Epoch Optical Observations
  10. GRB 031220: Optical observations of Chandra X-ray sources
  11. GRB040106: optical observations with REM+ROSS
  12. GRB031220: observation at Univercity of Miyazaki
  13. GRB 040106: Optical observations
  14. GRB 040106 : a long GRB detected with INTEGRAL
  15. IPN triangulation of an intermediate burst from SGR1806-20
  16. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  17. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  18. IPN triangulation of GRB031219 (large error box)
  19. GRB031220: Palomar Observations
  20. GRB 031220 : Kyoto Optical Observation
  21. GRB 031220: Subaru observation
  22. GRB 031220: Optical observation at Tokyo Tech
  23. GRB031220 : Optical Observation of Lulin Observatory
  24. GRB 031203 I-band monitoring
  25. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  26. GRB 2974 follow-up observations
  27. GRB031203, improved XMM position
  28. GRB 031203: Discovery of a dust echo
  29. GRB 031203: SMARTS optical monitoring
  30. GRB 021203: A Normal GRB viewed far off axis?
  31. XMM-Newton Observations of GRB031203: Preliminary Images
  32. GRB 031203: Variable Radio Source
  33. GRB 031203: Magellan spectrum of possible GRB host
  34. GRB 031203: Optical/IR Astrometry
  35. IPN/HETE localization of GRB031203B (=H2949; large error box)
  36. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  37. GRB 031203: Deep NIR NTT & VLT observations
  38. GRB031203: K' Photometry of the likely GRB host
  39. GRB 031203: Radio detection
  40. GRB 031203: Further reports on December 4 observations
  41. GRB 031203: IR NTTobservations do not confirm REM detection
  42. GRB031203 : Optical Observation of Lulin Observatory
  43. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  44. GRB 031203: Apparent Spectral Break
  45. GRB 031203: IR REM Observations
  46. GRB031203: Optical Observations
  47. GRB 031203 XMM-Newton observation
  48. GRB 031203: Optical/IR SMARTS Observations
  49. GRB 031203: A long GRB detected with INTEGRAL
  50. IPN triangulation of GRB031130 (large error box)
  51. GRB031111A, prompt optical observations
  52. GRB 031111B (= H2925) : Kyoto Optical Observation
  53. IPN/HETE localization of GRB031109 (=H2917; large error box)
  54. GRB 031111, Radio observations
  55. GRB 031111: Optical observations
  56. GRB 031111, optical observations
  57. SN 2003jd (SN/GRB?) -- X-ray Observations
  58. HETE Prompt GRB Spectral Analyses
  59. XRF031109 (=H2919): A very long XRF localized by HETE
  60. IPN triangulation of GRB031108 (large error box)
  61. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  62. GRB030929/SN2003jd association unlikely based on IPN localiztion
  63. Lulin optical follow-up observations of GRB031026
  64. SN 2003jd (SN/GRB?), Radio Observations
  65. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  66. GRB 031026: Further Ic Observations
  67. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  68. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  69. IPN triangulation of GRB031024 (single error box)
  70. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  71. GRB 031026: Ic Observations
  72. GRB031026 : KISO optical follow-up observation
  73. GRB030329: radio observations at RT-22 (CrAO)
  74. Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
  75. XRF 030824: additional observations at CFHT
  76. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  77. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  78. IPN detection of continued activity from SGR1806-20
  79. XRF 030723: Subaru Optical Observations
  80. A burst from SGR 1806-20 detected with IBAS
  81. XRF 030824: Early follow-up observation at Kiso observatory
  82. XRF 030824: observations at CFHT
  83. XRF 030723: Detection of the likely host galaxy
  84. GRB030913: Subaru Optical Observations
  85. GRB 030913: ROTSE-3c Optical Observations
  86. GRB030913: OT's limit by MASTER
  87. GRB030913, candidate afterglow observations
  88. GRB 030913, optical candidate
  89. GRB030913: AAVSO optical observations
  90. GRB 030913, BOOTES observations
  91. GRB030913 (=H2849): Confirmation of the Flight Localization
  92. GRB030913 (=H2849): TAROT Observations
  93. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  94. Magellan Observations of GRB030725 (=H2779)
  95. GRB 030913: Optical limit at RIKEN
  96. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  97. XRF030824: Optical observations
  98. IPN triangulation of GRB030903 (large error box)
  99. IBAS detection of bursts from SGR 1806-20
  100. Radio Observations of SGR1806-20

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