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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

3382 results found.

  1. LIGO/Virgo S190426c: GRAWITA transients from Asiago Schmidt wide field observations
  2. LIGO/Virgo S190425z: DECam Observations of the UVOT Candidate Region
  3. LIGO/Virgo S190426c: Continued LOAO Observation
  4. LIGO/Virgo S190425z: VISTA K-band observations of the Swift/UVOT Transient
  5. Fermi Trigger 578170097 / GRB 190428783 / GRB190428A: BALROG localization
  6. LIGO/Virgo S190426c: Additional Candidates from the Zwicky Transient Facility
  7. LIGO/Virgo S190426c: Continued infrared wide-field search with Palomar Gattini-IR
  8. LIGO/Virgo S190425z : IRSF/SIRIUS NIR photometric follow-up observation of the Swift/UVOT Transient
  9. LIGO/Virgo S190426c: OAJ-GRANDMA observation report
  10. LIGO/Virgo S190425z: No source found at UVOT source location at 6 hrs after LVC report
  11. LIGO/Virgo S190426c: DDOTI/OAN Optical Observations
  12. LIGO/Virgo S190425z: Lulin observations of the Swift/UVOT transient
  13. LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
  14. LIGO/Virgo S190426c: MMT Follow-Up Observations
  15. LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
  16. GRB 190427A: COATLI Optical Observations
  17. LIGO/Virgo S190426c: CNEOST Optical Observations
  18. LIGO/Virgo S190425z: CNEOST Optical Observations
  19. LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
  20. LIGO/Virgo S190425z: Additional Pan-STARRS transients in the skymap
  21. LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
  22. LIGO/Virgo S190426c: SAO optical observation
  23. LIGO/Virgo S190425z: Further MMT Follow-Up Observations
  24. LIGO/Virgo S190425z: COATLI Observations of Galaxies
  25. LIGO/Virgo S190426c: HAWC follow-up
  26. LIGO/Virgo S190425z: YAHPT Optical Observation
  27. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  28. LIGO/Virgo S190425z: KMTNet Observation
  29. LIGO/Virgo S190425z: Swope follow-up observations
  30. LIGO/Virgo S190425z: KPED Follow-Up Observations
  31. LIGO/Virgo S190425z: OVRO-LWA simultaneous low frequency radio observations of localization region
  32. LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
  33. LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
  34. LIGO/Virgo S190408an: Gaia Photometric Alerts transient candidates
  35. LIGO/Virgo S190425z: Fermi GBM Observations
  36. LIGO/Virgo S190425z: Lick/KAIT Follow-Up Observations
  37. Fermi GRB190425.09 Global MASTER-Net observations report
  38. LIGO/Virgo S190421ar: TAROT-GRANDMA observation report.
  39. LIGO/Virgo S190421ar: Lick/KAIT Follow-Up Observations
  40. Fermi GRB190420.98 Global MASTER-Net observations report
  41. Fermi GRB190419.41 Global MASTER-Net observations report
  42. LIGO/Virgo S190412m: GOTO optical coverage - no notable counterparts
  43. LIGO/Virgo S190408an: MAXI/GSC Observations
  44. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  45. LIGO/Virgo S190408an: CALET Observations
  46. CORRECTED TARGET NAME: GRB 190408A: MAXI/GSC detection
  47. GRB 140408A: MAXI/GSC detection
  48. GRB 140404B: MAXI/GSC detection
  49. GRB 190331B: Swift observations of a ground-detected burst
  50. GRB 190326A: 2.2m CAHA telescope optical limit
  51. Swift Trigger 895479: Detection of GRO J2058+42
  52. Swift Trigger 895257: Detection of GRO J2058+42 in outburst
  53. GRB 190326A: Swift detection of a short burst
  54. SWIFT GRB190323.85 Global MASTER-Net observations report
  55. Swift Trigger 894268: Detection of GRO J2058+42 in outburst
  56. Fermi Trigger 574676902 / GRB 190319353: BALROG localization
  57. GRB190219A: MASTER Global Robotic Net optical observation
  58. GRB190211A: GROWTH-India detection of optical afterglow
  59. GRB 190211A: DOAO optical observation
  60. Trigger 888312: Swift detection of 4U 1901+03
  61. GRB 190204A: MAXI/GSC detection
  62. Swift Trigger 887541: Swift detection of Swift J1728.9-3613
  63. IPN Triangulation of GRB 190129B (long/extremely bright)
  64. Swift Trigger 886157: MASTER optical observation
  65. Trigger 885456: Swift detection of MAXI J1631-479
  66. GRB 190114C: RTT150 optical observations
  67. GRB 190114B: optical afterglow observations in Mondy and Abastumani observatories
  68. GRB 190114B: Mondy optical afterglow detection
  69. GRB 190114C: NOT optical counterpart and redshift
  70. Konus-Wind observation of GRB 190103A
  71. GRB 190109A: Swift-BAT refined analysis
  72. Trigger 882561: Swift detection of MAXI J1631-479
  73. GRB 181228A: Mondy and AbAO optical upper limits
  74. GRB 181228A: possible NOT optical detection
  75. GRB 181228A: Xinglong-2.16m optical upper limit
  76. FRB 181228: Global MASTER Net optical inspection
  77. GRB 181227A: Global MASTER Net oprtical inspection
  78. Swift Trigger 880127 is not a GRB
  79. GRB 181228A: TSHAO optical upper limit
  80. GRB 181228A: Fermi GBM observation
  81. GRB 181228A: Global MASTER Net OT detection
  82. GRB 181228A: REM NIR detection
  83. GRB 181126A: MeerKAT radio observation
  84. GRB 181126B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 564897175)
  85. Swift Trigger 874754 is likely not an astrophysical event
  86. GRB 181201A: Zeiss-1000/CrAO optical observations
  87. GRB 181201A: Swift-XRT afterglow detection
  88. Short-duration GRB 181121.4: MASTER-Tavrida possible OT detection near the PGC galaxy during large Fermi error box inspection
  89. GRB 181028A: CALET Gamma-Ray Burst Monitor detection
  90. GRB 181030A: Swift detection of a burst with a possible optical counterpart
  91. GRB 181028A: Fermi GBM observation
  92. GRB 181028A: Fermi-LAT detection
  93. GRB 181027A: Swift detection of a burst
  94. Swift Trigger 866757: is probably not a GRB
  95. GRB 181011A: MAXI/GSC detection
  96. GRB 181008A: Insight-HXMT/HE detection
  97. GRB 181002A: Swift detection of a burst
  98. GRB 180923A: MAXI/GSC detection
  99. GRB 180914B : continued TSHAO optical observations
  100. GRB 180914B: MASTER OT automatic dtection

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