Fig.2.Leader: Veselka Siderova Radeva,
Astronomical Observatory, Varna, Bulgaria

1. Introduction

Comets are the most impressive objects in the Solar system. They, together with asteroids and meteors, belong to the group of small bodies in the Solar system. Bright comets on the night sky are among the most beautiful and breath-taking sights observed in nature! In this project we present to you the bright comet K4 LINEAR that we observed during the International Astronomical Summer School in the National Astronomical Observatory in Rozhen in August 2004.

The LINEAR project announced the discovery of an asteroidal object on images obtained on 2003 May 28.38. The magnitude was given as 17.6. Follow-up observations were obtained by J. McGaha (Tucson, Arizona, USA) and J. Young (Table Mountain Observatory, California, USA). McGaha obtained CCD images on May 29.4 which revealed a nuclear condensation 3 arc seconds across and a coma 6 arc seconds across. He noted that the coma was offset toward the northeast. Young imaged the comet on May 29.5 and May 30.4, and noted a round coma 5-7 arc seconds across, with a total magnitude of 17.5
The comet has been discovered with The GTS-2 Telescope. The GTS-2 telescope is a 1 meter folded prime focus Cassegrain design identical to that of the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) telescope used by the Air Force for space surveillance. It is located at the Experimental Test Site (ETS).[2]

Fig.5 Comet C/2003 K4
08/08/2004 Exp.120sec Filter: B
Image made by Veselka Radeva,
Nadezhda Radeva and Hristo Stoev

• Following the discovery, the comet was well followed during the remainder of 2003. D. Tirelli (Sossano, Italy) obtained an excellent series of observations using a 25-cm reflector and a CCD camera from July through October, which revealed a brightening from magnitude 17.0 on July 3 to 15.0 on September 16. He reported slightly fainter magnitudes of 15.7 to 15.8 during the latter half of October. Before the end of 2003, R. Ligustri (Talmassons, Italy) observed with a 35-cm reflector and a CCD camera and gave the magnitude as 14.8 on December 12.

• The comet continued to slowly brighten during April and May. Observers generally reported a magnitude around 11.5 in the beginning of April, while it had increased to about 11 as the month ended. The coma diameter was generally around 1 arc minute during the first half of April, and was around 1.2 arc minutes as the month came to a close. M. Lehky (Hradec Kralove, Czech Republic) reporting the first observations using binoculars, which had a size of 25x100. In addition, on April 27, Walter Kutschera (Germany) reported a tail about 1 arc minute long. On May 1, observers generally estimated the magnitude as 11, while the coma was perhaps 1.2 arc minutes across. During the last days of May most observers estimated the magnitude as between 9.7 and 10.0, while the coma diameter was around 2.5 arc minutes.

• Up to this point in the comet's brightness evolution, the visual observations could be represented by a fairly uneventful curve that indicated a potential maximum brightness of 7 during October of 2004, but this all changed a few days into June. By June 4, the comet had brightened to a magnitude of approximately 9.5 andwas displaying a coma about

• A newcomer to the Solar system, C/2003 K4 LINEAR reaches perihelion on October 14th 2004. This occurs on the opposite side of the Sun and thus will not become a bright object from Earth's point of view. On June 1st 2004, the comet was situated in Lyra and shone at about 10th magnitude. It gradually brightened as it traversed the constellation of Hercules. By July 5th, the comet could be observed in Bootes and it was visible in the northern evening sky at about 8th magnitude. It crossed into Coma Berenices on Aug 11th, about 5 degrees east of the globular cluster pair M53 and NGC 5053. On August 20th, the comet was situated in Virgo and shone at magnitude 6.5. The comet was lost in the evening twilight by the middle of September.
Between September 28th and October 10th, the comet was visible in the SOHO LASCO C3 Coronagraph. You can see real-time movies from this period at: http://sohowww.nascom.nasa.gov/data/realtime/mpeg/
At the end of October 2004, LINEAR was picked up in the constellation of Corvus in the morning sky and at peak brightness of about magnitude 5.5.
Nov to mid Dec 2004
Comet 2003 K4 LINEAR should maintain a constant brightness of approximately magnitude 5.5-6.0 and be a nice binocular-telescopic sight in the morning sky. Naked eye observations may be possible at this time. By early December, Comet 2003 K4 becomes visible low in the south-eastern late evening sky, trekking through the rich milky way regions of Vela, but still better viewed before dawn. This was the opportunity to observe both 2003 K4 and 2004 Q2 with the naked eye simultaneously although this was quite an observing challenge.
Mid to Late December 2004
Preferably observed before dawn as moonlight interferes during evening hours.The comet is in Carina and it shines at approximately magnitude 6.0-6.5.
Note close approach to open star cluster NGC 2516 on Christmas night.
Jan 2005
The comet shines around magnitude 6.5-7.0 by the start of January and it is in the southern evening sky. It rapidly fades as it recedes from both Sun and Earth.

4. Main characteristics - Orbital Elements of C/2003 K4

The orbital elements are taken from MPC 52 315. From 2244 observations 2003 May 28-2004 July 9 the following orbital parameters have been calculated. We will show some of them that will give us a notion of the comet's orbit.[3]

Fig.16 - Creation of the nucleus - Step1

Fig. 17- Creation of the Comet - Step 2

Fig.18 - Comet from ice cream - Step 3