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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').

10636 results found.

  1. GRB021211, OT at 108 s
  2. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  3. HETE 2493: Optical observations
  4. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  5. IPN detection of renewed activity from SGR1806-20
  6. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  7. IPN detection of continued SGR1900+14 activity
  8. Improved IPN error box for GRB021125
  9. GRB021125 : A long GRB localized by INTEGRAL
  10. IPN confirmation of the reactivation of SGR1900+14
  11. IPN detection of possible reactivation of SGR1900+14
  12. IPN triangulation of GRB021119 (annulus)
  13. GRB021112: Optical Observations
  14. GRB021113 (=H2449): A Long GRB Localized by HETE
  15. GRB021112 (=H2448): A Long GRB Localized by HETE
  16. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  17. SGR1900+14 activity, November 2-4, 2002
  18. Detection of activity from SGR 1900+14 with the RXTE/PCA
  19. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  20. GRB 021004: optical observations
  21. IPN triangulation of GRB021020 (smaller error box)
  22. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  23. IPN triangulation of GRB021020
  24. GRB 021016, optical observations
  25. GRB 021004: VRI observations at TNG: possible break
  26. GRB 021008, optical observations
  27. GRB021016(=H2397): A Long GRB Localized by HETE
  28. GRB021004: NIR and Optical observations
  29. GRB 021004: Optical measurement at OHP
  30. GRB 021004: optical spectroscopy
  31. GRB021004: BVRc photometry
  32. GRB 021004: Optical Photometry at 2.5 Days
  33. GRB 021004 radio observation
  34. GRB 021004: Optical Observations
  35. GRB 021004: Optical Photometry at 1.5 Days
  36. GRB021004, Optical Observations
  37. GRB 021004, optical observations
  38. GRB 021004, SPM optical observations
  39. GRB 021004: steepening of the optical decay slope
  40. XRF020903, BVRI field photometry
  41. GRB 020903: Optical observations at RIKEN
  42. XRF 020903: Supernova
  43. IPN triangulation of GRB020926 (two large error boxes)
  44. GRB020924 (ecliptic latitude-only localization)
  45. IPN triangulation of GRB020923 (two error boxes)
  46. Improved IPN position for GRB020918 (two large error boxes)
  47. IPN triangulation of GRB020911 (2 large error boxes)
  48. IPN detection of a burst from SGR1900+14
  49. INTEGRAL GRBs added to GCN
  50. GRB020812: optical observation
  51. Second epoch K band imaging of GRB 020819
  52. GRB 020812: early time optical observation at Ouda Station
  53. GRB020813: Magellan BVRI Photometry
  54. GRB 020819 : OT candidate - confirmation of non variability
  55. K band observation of GRB 020819
  56. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  57. IPN triangulation of GRB020819 (HETE 2275)
  58. GRB020813: Fading X-ray Afterglow Observed with Chandra
  59. GRB020812: NIR observations
  60. GRB020812: optical observations
  61. GRB 020812 : optical afterglow candidate
  62. GRB020813, optical observations
  63. GRB 020812 optical observation
  64. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  65. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  66. GRB020801, optical afterglow candidate
  67. IPN triangulation of GRB020714
  68. GRB 020410: Discovery of Probable OT by HST
  69. Correction to IPN error box for GRB020706
  70. IPN triangulation of GRB020706
  71. GRB 020705: Optical observations
  72. GRB020625 (=H2081): A Long Burst Localized by HETE
  73. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  74. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  75. AXP 1E2259+586: quasi-simultaneous optical observation
  76. AXP 1E2259+586 optical observations
  77. SGR-like Bursts from the AXP 1E 2259+586
  78. GRB 020531, simultaneous optical observations
  79. GRB020531: Second epoch Chandra observations
  80. GRB020531: Observations with the Chandra X-ray Observatory
  81. GRB020531, optical observation
  82. IPN triangulation of the short, hard GRB020531 (=H2042)
  83. GRB020525, optical observations
  84. IPN detection of possible bursts from SGR1806-20
  85. IPN triangulation of GRB020525
  86. XRF 020427: Sudden Ionospheric Disturbance (SID)
  87. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  88. IPN triangulation of a burst from SGR1806-20
  89. GRB 020410, Radio Observations
  90. GRB 020124: Optical observations
  91. IPN triangulation of GRB020418
  92. GRB020410: BeppoSAX NFI observations refined analysis
  93. Mars Odyssey joins the IPN
  94. IPN triangulation of GRB020413
  95. GRB 020409 SARA Observations
  96. GRB 020409, No Optical Detection to R = 20
  97. GRB020410: BeppoSAX NFI observation
  98. GRB 020409, optical observations
  99. GRB020406(?), optical observations
  100. BeppoSAX ALERT: possible GRB020410

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